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Rancière F, Wafo O, Perrot X, Momas I. Associations between heat wave during pregnancy and term birth weight outcomes: The PARIS birth cohort. ENVIRONMENT INTERNATIONAL 2024; 188:108730. [PMID: 38776654 DOI: 10.1016/j.envint.2024.108730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 04/28/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024]
Abstract
BACKGROUND Climate change will make extreme weather events more frequent in the 21st century. Extreme ambient temperatures during the prenatal period have been associated with adverse pregnancy outcomes such as preterm birth. It is unclear, however, whether heat waves during pregnancy impact fetal growth in apparently healthy term newborns. OBJECTIVES We aimed to investigate associations between heat wave during pregnancy and birth weight outcomes in term newborns from the PARIS birth cohort, and to explore meteorological conditions and air pollution as possible intermediate factors. METHODS We examined data on 3,359 newborns born between 37 and 42 weeks in Paris, France, between 2003 and 2006. Associations of maternal exposure to heat wave (during whole pregnancy and each trimester) with birth weight and small for gestational age (SGA) at term were studied using linear and logistic regression models adjusted for potential confounders. Maternal characteristics were investigated as possible modifiers. We explored the mediating role of ambient temperature, relative humidity, and air pollution levels in the relationship between heat wave during the first trimester and term SGA. RESULTS Mothers who were pregnant during the 2003 French heat wave (n = 506, 15 %) were more likely to have a term SGA baby (aOR = 2.70; 95 %CI: 1.38, 5.28) compared to mothers who did not experience heat wave during pregnancy. The association was stronger when heat wave occurred during the first trimester (aOR = 4.18; 95 %CI: 1.69, 10.35). Primiparous women were identified as more vulnerable than multiparous women. Average ambient temperature and air quality index explained about 36 % and 56 % of the association between heat wave during the first trimester and term SGA, respectively. CONCLUSIONS This study suggests prenatal exposure to heat wave, especially during the first trimester, may adversely affect fetal growth of term newborns, which could be explained by both increasing ambient temperatures and worsening air quality.
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Affiliation(s)
- Fanny Rancière
- Université Paris Cité, Inserm U1153 CRESS, Inrae, HERA team, Paris, France; Faculté de Pharmacie de Paris, Université Paris Cité, Paris, France.
| | - Octave Wafo
- Université Paris Cité, Inserm U1153 CRESS, Inrae, HERA team, Paris, France
| | - Xavier Perrot
- Laboratoire de Météorologie Dynamique, Ecole Normale Supérieure, CNRS, Paris, France
| | - Isabelle Momas
- Université Paris Cité, Inserm U1153 CRESS, Inrae, HERA team, Paris, France; Faculté de Pharmacie de Paris, Université Paris Cité, Paris, France; Cellule Cohorte, Direction de l'Action Sociale de l'Enfance et de la Santé, Mairie de Paris, Paris, France
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Weeda LJZ, Bradshaw CJA, Judge MA, Saraswati CM, Le Souëf PN. How climate change degrades child health: A systematic review and meta-analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 920:170944. [PMID: 38360325 DOI: 10.1016/j.scitotenv.2024.170944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 02/08/2024] [Accepted: 02/11/2024] [Indexed: 02/17/2024]
Abstract
BACKGROUND Children are more vulnerable than adults to climate-related health threats, but reviews examining how climate change affects human health have been mainly descriptive and lack an assessment of the magnitude of health effects children face. This is the first systematic review and meta-analysis that identifies which climate-health relationships pose the greatest threats to children. OBJECTIVES We reviewed epidemiologic studies to analyse various child health outcomes due to climate change and identify the relationships with the largest effect size. We identify population-specific risks and provide recommendations for future research. METHODS We searched four large online databases for observational studies published up to 5 January 2023 following PRISMA (systematic review) guidelines. We evaluated each included study individually and aggregated relevant quantitative data. We used quantitative data in our meta-analysis, where we standardised effect sizes and compared them among different groupings of climate variables and health outcomes. RESULTS Of 1301 articles we identified, 163 studies were eligible for analysis. We identified many relationships between climate change and child health, the strongest of which was increasing risk (60 % on average) of preterm birth from exposure to temperature extremes. Respiratory disease, mortality, and morbidity, among others, were also influenced by climate changes. The effects of different air pollutants on health outcomes were considerably smaller compared to temperature effects, but with most (16/20 = 80 %) pollutant studies indicating at least a weak effect. Most studies occurred in high-income regions, but we found no geographical clustering according to health outcome, climate variable, or magnitude of risk. The following factors were protective of climate-related child-health threats: (i) economic stability and strength, (ii) access to quality healthcare, (iii) adequate infrastructure, and (iv) food security. Threats to these services vary by local geographical, climate, and socio-economic conditions. Children will have increased prevalence of disease due to anthropogenic climate change, and our quantification of the impact of various aspects of climate change on child health can contribute to the planning of mitigation that will improve the health of current and future generations.
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Affiliation(s)
- Lewis J Z Weeda
- School of Medicine, University of Western Australia, Perth, Western Australia, Australia.
| | - Corey J A Bradshaw
- Global Ecology | Partuyarta Ngadluku Wardli Kuu, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia; Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, EpicAustralia.org.au, Australia
| | - Melinda A Judge
- Telethon Kids Institute, Perth, Western Australia, Australia; Department of Mathematics and Statistics, University of Western Australia, Perth, Western Australia, Australia
| | | | - Peter N Le Souëf
- School of Medicine, University of Western Australia, Perth, Western Australia, Australia; Telethon Kids Institute, Perth, Western Australia, Australia
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Bonell A, Part C, Okomo U, Cole R, Hajat S, Kovats S, Sferruzzi-Perri AN, Hirst JE. An expert review of environmental heat exposure and stillbirth in the face of climate change: Clinical implications and priority issues. BJOG 2024; 131:623-631. [PMID: 37501633 DOI: 10.1111/1471-0528.17622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 07/11/2023] [Indexed: 07/29/2023]
Abstract
Exposure to extreme heat in pregnancy increases the risk of stillbirth. Progress in reducing stillbirth rates has stalled, and populations are increasingly exposed to high temperatures and climate events that may further undermine health strategies. This narrative review summarises the current clinical and epidemiological evidence of the impact of maternal heat exposure on stillbirth risk. Out of 20 studies, 19 found an association between heat and stillbirth risk. Recent studies based in low- to middle-income countries and tropical settings add to the existing literature to demonstrate that all populations are at risk. Additionally, both short-term heat exposure and whole-pregnancy heat exposure increase the risk of stillbirth. A definitive threshold of effect has not been identified, as most studies define exposure as above the 90th centile of the usual temperature for that population. Therefore, the association between heat and stillbirth has been found with exposures from as low as >12.64°C up to >46.4°C. The pathophysiological pathways by which maternal heat exposure may lead to stillbirth, based on human and animal studies, include both placental and embryonic or fetal impacts. Although evidence gaps remain and further research is needed to characterise these mechanistic pathways in more detail, preliminary evidence suggests epigenetic changes, alteration in imprinted genes, congenital abnormalities, reduction in placental blood flow, size and function all play a part. Finally, we explore this topic from a public health perspective; we discuss and evaluate the current public health guidance on minimising the risk of extreme heat in the community. There is limited pregnancy-specific guidance within heatwave planning, and no evidence-based interventions have been established to prevent poor pregnancy outcomes. We highlight priority research questions to move forward in the field and specifically note the urgent need for evidence-based interventions that are sustainable.
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Affiliation(s)
- Ana Bonell
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Cherie Part
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Uduak Okomo
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Rebecca Cole
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Shakoor Hajat
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Sari Kovats
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Amanda N Sferruzzi-Perri
- Department of Physiology, Development and Neuroscience, Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
| | - Jane E Hirst
- Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK
- The George Institute for Global Health, Imperial College London, London, UK
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Saraswati CM, Judge MA, Weeda LJZ, Bassat Q, Prata N, Le Souëf PN, Bradshaw CJA. Net benefit of smaller human populations to environmental integrity and individual health and wellbeing. Front Public Health 2024; 12:1339933. [PMID: 38504675 PMCID: PMC10949988 DOI: 10.3389/fpubh.2024.1339933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 02/13/2024] [Indexed: 03/21/2024] Open
Abstract
Introduction The global human population is still growing such that our collective enterprise is driving environmental catastrophe. Despite a decline in average population growth rate, we are still experiencing the highest annual increase of global human population size in the history of our species-averaging an additional 84 million people per year since 1990. No review to date has accumulated the available evidence describing the associations between increasing population and environmental decline, nor solutions for mitigating the problems arising. Methods We summarize the available evidence of the relationships between human population size and growth and environmental integrity, human prosperity and wellbeing, and climate change. We used PubMed, Google Scholar, and Web of Science to identify all relevant peer-reviewed and gray-literature sources examining the consequences of human population size and growth on the biosphere. We reviewed papers describing and quantifying the risks associated with population growth, especially relating to climate change. Results These risks are global in scale, such as greenhouse-gas emissions, climate disruption, pollution, loss of biodiversity, and spread of disease-all potentially catastrophic for human standards of living, health, and general wellbeing. The trends increasing the risks of global population growth are country development, demographics, maternal education, access to family planning, and child and maternal health. Conclusion Support for nations still going through a demographic transition is required to ensure progress occurs within planetary boundaries and promotes equity and human rights. Ensuring the wellbeing for all under this aim itself will lower population growth and further promote environmental sustainability.
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Affiliation(s)
| | - Melinda A. Judge
- Telethon Kids Institute, Perth, WA, Australia
- School of Mathematics and Statistics, University of Western Australia, Nedlands, WA, Australia
| | - Lewis J. Z. Weeda
- School of Medicine, University of Western Australia, Nedlands, WA, Australia
| | - Quique Bassat
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
- Paediatrics Department, Hospital Sant Joan de Déu, Universitat de Barcelona, Esplugues, Barcelona, Spain
- Centro de Investigación Biomédica en Red (CIBER) de Epidemiología y Salud Pública, Instituto de Salud Carlos III, Madrid, Spain
| | - Ndola Prata
- Bixby Center for Population Health and Sustainability, School of Public Health, University of California, Berkeley, Berkeley, CA, United States
| | - Peter N. Le Souëf
- School of Medicine, University of Western Australia, Nedlands, WA, Australia
| | - Corey J. A. Bradshaw
- Global Ecology | Partuyarta Ngadluku Wardli Kuu, College of Science and Engineering, Flinders University, Adelaide, SA, Australia
- Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, Wollongong, NSW, Australia
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Lo Y, Vosper E, Higgins JP, Howard G. Heat impacts on human health in the Western Pacific Region: an umbrella review. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2024; 42:100952. [PMID: 38022710 PMCID: PMC10652124 DOI: 10.1016/j.lanwpc.2023.100952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 10/13/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023]
Abstract
Background High temperatures and heatwaves are occurring more frequently and lasting longer because of climate change. A synthesis of existing evidence of heat-related health impacts in the Western Pacific Region (WPR) is lacking. This review addresses this gap. Methods The Scopus and PubMed databases were searched for reviews about heat impacts on mortality, cardiovascular morbidity, respiratory morbidity, dehydration and heat stroke, adverse birth outcomes, and sleep disturbance. The last search was conducted in February 2023 and only publications written in English were included. Primary studies and reviews that did not include specific WPR data were excluded. Data were extracted from 29 reviews. Findings There is strong evidence of heat-related mortality in the WPR, with the evidence concentrating on high-income countries and China. Associations between heat and cardiovascular or respiratory morbidity are not robust. There is evidence of heat-related dehydration and stroke, and preterm and still births in high-income countries in the WPR. Some evidence of sleep disturbance from heat is found for Australia, Japan and China. Interpretation Mortality is by far the most studied and robust health outcome of heat. Future research should focus on morbidity, and lower income countries in continental Asia and Pacific Island States, where there is little review-level evidence. Funding Funded by the World Health Organization WPR Office.
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Affiliation(s)
- Y.T.Eunice Lo
- Cabot Institute for the Environment, University of Bristol, UK
- Elizabeth Blackwell Institute for Health Research, University of Bristol, UK
| | - Emily Vosper
- Cabot Institute for the Environment, University of Bristol, UK
- School of Geographical Sciences, University of Bristol, UK
| | - Julian P.T. Higgins
- Population Health Sciences, Bristol Medical School, University of Bristol, UK
- NIHR Applied Research Collaboration West (ARC West) at University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | - Guy Howard
- Cabot Institute for the Environment, University of Bristol, UK
- School of Civil, Aerospace and Design Engineering, University of Bristol, UK
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Singh T, Jalaludin B, Hajat S, Morgan GG, Meissner K, Kaldor J, Green D, Jegasothy E. Acute air pollution and temperature exposure as independent and joint triggers of spontaneous preterm birth in New South Wales, Australia: a time-to-event analysis. Front Public Health 2023; 11:1220797. [PMID: 38098836 PMCID: PMC10720724 DOI: 10.3389/fpubh.2023.1220797] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 10/23/2023] [Indexed: 12/17/2023] Open
Abstract
Introduction Exposure to high ambient temperatures and air pollution has been shown to increase the risk of spontaneous preterm birth (sPTB). Less clear are the effects of cold and the joint effects of air pollution and temperature. Methods Using a Cox proportional hazard regression model, we assessed the risk of independent and combined short-term exposure to ambient daily mean temperature and PM2.5 associated with sPTB in the last week before delivery on overall sPTB (weeks 23-36) and three subtypes: extremely sPTB, very sPTB, and moderate-to-late sPTB for a birth cohort of 1,318,570 births from Australia (Jan 2001-Dec 2019), while controlling for chronic exposure (i.e., throughout pregnancy except the last week before delivery) to PM2.5 and temperature. The temperature was modeled as a natural cubic spline, PM2.5 as a linear term, and the interaction effect was estimated using a multiplicative term. For short-term exposure to temperature hazard ratios reported are relative to the median temperature (18.1°C). Results Hazard ratios at low temperature [5th percentile(11.5°C)] were 0.95 (95% CI: 0.90, 1.00), 1.08 (95% CI: 0.84, 1.4), 0.87 (95% CI: 0.71, 1.06), and 1.00 (95% CI: 0.94, 1.06) and greater for high temperature [95th percentile (24.5°C)]: 1.22 (95% CI: 1.16, 1.28), 1.27 (95% CI: 1.03, 1.57), and 1.26 (95% CI: 1.05, 1.5) and 1.05 (1.00, 1.11), respectively, for overall, extremely, very, and moderate-to-late sPTBs. While chronic exposure to PM2.5 had adverse effects on sPTB, short-term exposure to PM2.5 appeared to have a negative association with all types of sPTB, with hazard ratios ranging from 0.86 (95th CI: 0.80, 0.94) to 0.98 (95th CI: 0.97, 1.00) per 5 μg/m3 increase in PM2.5. Discussion The risk of sPTB was found to increase following acute exposure to hot and cold ambient temperatures. Earlier sPTB subtypes seemed to be the most vulnerable. This study adds to the evidence that short-term exposure to ambient cold and heat and longer term gestational exposure to ambient PM2.5 are associated with an elevated risk of sPTB.
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Affiliation(s)
- Tanya Singh
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- Australian Research Council Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia
| | - Bin Jalaludin
- School of Population Health, University of New South Wales, Kensington, NSW, Australia
- Ingham Institute for Applied Medical Research, University of New South Wales, Sydney, NSW, Australia
| | - Shakoor Hajat
- Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Geoffrey G. Morgan
- School of Public Health, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
- University Centre for Rural Health, Faculty of Medicine and Health, University of Sydney, Lismore, NSW, Australia
- Healthy Environments and Lives (HEAL) National Research Network, Australian National University, Canberra, ACT, Australia
- Centre for Air Pollution, Energy and Health Research (CAR), Glebe, NSW, Australia
| | - Katrin Meissner
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- Australian Research Council Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia
| | - John Kaldor
- Kirby Institute, University of New South Wales, Sydney, NSW, Australia
| | - Donna Green
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- Australian Research Council Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia
| | - Edward Jegasothy
- School of Public Health, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
- University Centre for Rural Health, Faculty of Medicine and Health, University of Sydney, Lismore, NSW, Australia
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Mehta M, Basu R, Ghosh R. Adverse effects of temperature on perinatal and pregnancy outcomes: methodological challenges and knowledge gaps. Front Public Health 2023; 11:1185836. [PMID: 38026314 PMCID: PMC10646498 DOI: 10.3389/fpubh.2023.1185836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 09/19/2023] [Indexed: 12/01/2023] Open
Abstract
Evidence linking temperature with adverse perinatal and pregnancy outcomes is emerging. We searched for literature published until 30 January 2023 in PubMed, Web of Science, and reference lists of articles focusing on the outcomes that were most studied like preterm birth, low birth weight, stillbirth, and hypertensive disorders of pregnancy. A review of the literature reveals important gaps in knowledge and several methodological challenges. One important gap is the lack of knowledge of how core body temperature modulates under extreme ambient temperature exposure during pregnancy. We do not know the magnitude of non-modulation of body temperature during pregnancy that is clinically significant, i.e., when the body starts triggering physiologic counterbalances. Furthermore, few studies are conducted in places where extreme temperature conditions are more frequently encountered, such as in South Asia and sub-Saharan Africa. Little is also known about specific cost-effective interventions that can be implemented in vulnerable communities to reduce adverse outcomes. As the threat of global warming looms large, effective interventions are critically necessary to mitigate its effects.
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Affiliation(s)
- Maitry Mehta
- Sawyer Business School, Suffolk University, Boston, MA, United States
| | - Rupa Basu
- California Environmental Protection Agency, Office of Environmental Health Hazard Assessment, Oakland, CA, United States
| | - Rakesh Ghosh
- Sawyer Business School, Suffolk University, Boston, MA, United States
- Institute for Health and Aging, University of California, San Francisco, San Francisco, CA, United States
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Gordon M, Casey JA, McBrien H, Gemmill A, Hernández D, Catalano R, Chakrabarti S, Bruckner T. Disparities in preterm birth following the July 1995 Chicago heat wave. Ann Epidemiol 2023; 87:S1047-2797(23)00166-7. [PMID: 37678645 PMCID: PMC10842513 DOI: 10.1016/j.annepidem.2023.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 08/20/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023]
Abstract
PURPOSE To evaluate if changes in preterm birth (PTB, <37 weeks of gestation) incidence differed between non-Hispanic (NH) Black and NH white births following the July 1995 Chicago heat wave-among the most severe U.S. heat waves since 1950. METHODS We used an ecologic study design. We obtained birth data from January 1990-December 1996 from the National Vital Statistics File to calculate the mean monthly PTB incidence in Chicago's Cook County, Illinois. Births between July 1995 and February 1996 were potentially exposed to the heat wave in utero. We generated time series models for NH Black and NH white births, which incorporated synthetic controls of Cook County based on unexposed counties. We ran a secondary analysis considering socioeconomic status (SES). RESULTS From 1990-1996, the mean monthly PTB incidence among NH Black births was 18.6% compared to 7.8% among NH white births. The mean monthly PTB incidence among NH Black births from August 1995-January 1996 was 16.7% higher than expected (three additional PTBs per 100 live births per month [95% confidence interval (CI): 1, 5]). A similar increase occurred among low-SES NH Black births. No increase appeared among NH white births. CONCLUSIONS Severe heat waves may increase racial disparities in PTB incidence.
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Affiliation(s)
- Milo Gordon
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY
| | - Joan A Casey
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY; Department of Environmental & Occupational Health Sciences, University of Washington, Seattle, WA
| | - Heather McBrien
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY
| | - Alison Gemmill
- Department of Population, Family, and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Diana Hernández
- Sociomedical Sciences Department, Columbia University Mailman School of Public Health, New York, NY
| | - Ralph Catalano
- School of Public Health, University of California, Berkeley
| | | | - Tim Bruckner
- Program in Public Health, University of California, Irvine.
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Yu G, Yang L, Liu M, Wang C, Shen X, Fan L, Zhang J. Extreme Temperature Exposure and Risks of Preterm Birth Subtypes Based on a Nationwide Survey in China. ENVIRONMENTAL HEALTH PERSPECTIVES 2023; 131:87009. [PMID: 37585350 PMCID: PMC10431497 DOI: 10.1289/ehp10831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 07/15/2023] [Accepted: 07/17/2023] [Indexed: 08/18/2023]
Abstract
BACKGROUND Previous studies have reported that ambient temperature may affect perinatal outcomes. However, whether extreme temperature affects the risk of preterm birth (PTB) remains controversial. Studies on the associations of extreme temperature with PTB subtypes are lacking. OBJECTIVES We aimed to investigate the associations of extreme climate events with the risks of PTB and its subtypes, discerning possible modifiers. METHODS Data on all singleton deliveries were obtained from the China Labor and Delivery Survey (CLDS), a nationwide investigation implemented in 2015 and 2016. PTB was defined as gestational weeks < 37 and then categorized as early (24-34 wk) and late PTBs (35-36 wk), and clinical subtypes [spontaneous PTB, preterm premature rupture of the fetal membranes (PPROM), iatrogenic PTB]. Ambient temperature data were provided by the China National Weather Data Sharing System. Five heat indexes and five cold indexes were used to define heat waves and cold spells. Generalized linear mixed models with a random term by hospital unit were used to assess the associations of short-term prenatal extreme temperature exposure. The Cox proportional hazard regression model was applied to assess the nonlinear associations of low- or high-temperature exposure at the whole and different trimesters of pregnancy with the risk of PTB. Stratified analyses were conducted to assess the possible modification by geographic region and fetal sex. RESULTS A total of 70,818 singleton births from 96 hospitals in China were included, among which 4,965 (7.01%) were PTBs. Exposure to extreme cold events 1 wk before delivery was associated with an increased PTB risk, with an adjusted odds ratio (aOR) [95% confidence intervals (CIs)] of 1.07 (95% CI: 1.04, 1.10) and 1.06 (1.04, 1.09) for the total days when the daily average temperature below the fifth percentile (fifth-days) and the 10th percentile (10th-days), 1.18 (1.04, 1.34) for the cold spells when the daily average temperature below the fifth percentile for two consecutive days (fifth-2D), 1.09 (1.03, 1.16) and 1.12 (1.06, 1.19) for the cold spells when the daily average temperature below the 10th percentile for three and two consecutive days (10th-3D and 10th-2D), respectively. Results of extreme temperature exposure during 2 weeks before delivery showed similarly significant associations. The association between cold spells and PTB tended to be stronger for late PTB than for early PTB. Cold spells were mainly associated with spontaneous PTB and late PPROM. A stratified analysis indicated that pregnant women in western and northern regions tended to be more sensitive to cold spells, and pregnant women with a female fetus appeared to be at a higher risk of PTB when exposed to cold spells. Pregnant women in late pregnancy were more susceptible to extreme temperatures. No significant or stable association was found between heat waves and preterm birth. DISCUSSION Exposure to cold spells was associated with an increased risk of PTB, especially late, spontaneous PTB and PPROM. The associations appeared to be more pronounced in the north and west regions and in pregnancies with female fetuses. https://doi.org/10.1289/EHP10831.
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Affiliation(s)
- Guoqi Yu
- Ministry of Education – Shanghai Key Laboratory of Children’s Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ling Yang
- Hainan Women and Children’s Medical Center, Hainan, China
| | - Ming Liu
- Department of Obstetrics, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Cuiping Wang
- Ministry of Education – Shanghai Key Laboratory of Children’s Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoli Shen
- Shanghai Jiao Tong University School of Public Health, Shanghai, China
| | - Lichun Fan
- Hainan Women and Children’s Medical Center, Hainan, China
| | - Jun Zhang
- Ministry of Education – Shanghai Key Laboratory of Children’s Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Jiao Tong University School of Public Health, Shanghai, China
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Guo Y, Chen P, Xie Y, Wang Y, Mu Y, Zhou R, Niu Y, Shi X, Zhu J, Liang J, Liu Q. Association of Daytime-Only, Nighttime-Only, and Compound Heat Waves With Preterm Birth by Urban-Rural Area and Regional Socioeconomic Status in China. JAMA Netw Open 2023; 6:e2326987. [PMID: 37566422 PMCID: PMC10422195 DOI: 10.1001/jamanetworkopen.2023.26987] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 06/22/2023] [Indexed: 08/12/2023] Open
Abstract
Importance Associations between heat waves and preterm birth (PTB) have been reported. However, associations of daytime-only, nighttime-only, and compound heat waves with PTB have yet to be explored at a national level. Furthermore, possible heterogeneity across urban-rural communities with different socioeconomic statuses needs to be explored. Objective To examine the association between daytime-only, nighttime-only, and compound heat waves and PTB in China and to find variations between urban and rural regions. Design, Setting, and Participants This case-crossover study used nationwide representative birth data between January 1, 2012, and December 31, 2019, from China's National Maternal Near Miss Surveillance System. This multisite study covered 30 provinces in China and ensured the representation of urban and rural populations across 3 socioeconomic regions. Singleton live births delivered in the warm seasons from April to October during the study period were included. Exclusion criteria consisted of gestational age younger than 20 or older than 45 weeks, maternal ages younger than 13 or older than 50 years, conception dates earlier than 20 weeks before January 1, 2012, and later than 45 weeks before December 31, 2019, and an inconsistent combination of birthweight and gestational age according to growth standard curves of Chinese newborns. Data were analyzed from September 10, 2021, to April 25, 2023. Exposures Eighteen definitions of heat waves by 3 distinct types, including daytime only (only daily maximum temperature exceeds thresholds), nighttime only (only daily minimum temperature exceeds thresholds), and compound (both daily maximum and minimum temperature exceeds thresholds) heat waves, and 6 indexes, including 75th percentile of daily temperature thresholds for 2 or more (75th-D2), 3 or more (75th-D3), or 4 or more (75th-D4) consecutive days and 90th percentile of daily temperature thresholds for 2 or more (90th-D2), 3 or more (90th-D3), and 4 or more (90th-D4) consecutive days. Main Outcomes and Measures Preterm births with less than 37 completed weeks of gestation. Results Among the 5 446 088 singleton births in the final analytic sample (maternal mean [SD] age, 28.8 [4.8] years), 310 384 were PTBs (maternal mean [SD] age, 29.5 [5.5] years). Compared with unexposed women, exposure of pregnant women to compound heat waves in the last week before delivery was associated with higher risk for PTB, with the adjusted odds ratios (AORs) ranging from 1.02 (95% CI, 1.00-1.03) to 1.04 (95% CI, 1.01-1.07) in 6 indexes. For daytime-only heat wave exposures, AORs ranged from 1.03 (95% CI, 1.01-1.05) to 1.04 (95% CI, 1.01-1.08) in the 75th-D4, 90th-D2, 90th-D3, and 90th-D4 indexes. Such associations varied by rural (AOR range, 1.05 [95% CI, 1.01-1.09] to 1.09 [95% CI, 1.04-1.14]) and urban (AOR range, 1.00 [95% CI, 0.98-1.02] to 1.01 [95% CI, 0.99-1.04]) regions during exposure to daytime-only heat waves in the 75th-D3 and 90th-D3 indexes. Conclusions and Relevance In this case-crossover study, exposure to compound and daytime-only heat waves in the last week before delivery were associated with PTB, particularly for pregnant women in rural regions exposed to daytime-only heat waves. These findings suggest that tailored urban-rural preventive measures may improve maternal health in the context of climate change.
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Affiliation(s)
- Yafei Guo
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Chinese Center for Disease Control and Prevention Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Peiran Chen
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Yanxia Xie
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Yanping Wang
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Yi Mu
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Ruobing Zhou
- Department of Health, Ethics and Society, Maastricht University, Maastricht, the Netherlands
| | - Yanlin Niu
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Institute for Nutrition and Food Hygiene, Beijing Center for Disease Prevention and Control, Beijing, China
| | - Xiaoming Shi
- Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jun Zhu
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Juan Liang
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Qiyong Liu
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Yüzen D, Graf I, Tallarek AC, Hollwitz B, Wiessner C, Schleussner E, Stammer D, Padula A, Hecher K, Arck PC, Diemert A. Increased late preterm birth risk and altered uterine blood flow upon exposure to heat stress. EBioMedicine 2023:104651. [PMID: 37355458 PMCID: PMC10363435 DOI: 10.1016/j.ebiom.2023.104651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/26/2023] Open
Abstract
BACKGROUND Climate change, in particular the exposure to heat, impacts on human health and can trigger diseases. Pregnant people are considered a vulnerable group given the physiological changes during pregnancy and the potentially long-lasting consequences for the offspring. Evidence published to date on higher risk of pregnancy complications upon heat stress exposure are from geographical areas with high ambient temperatures. Studies from geographic regions with temperate climates are sparse; however, these areas are critical since individuals may be less equipped to adapt to heat stress. This study addresses a significant gap in knowledge due to the temperature increase documented globally. METHODS Birth data of singleton pregnancies (n = 42,905) from a tertiary care centre in Hamburg, Germany, between 1999 and 2021 were retrospectively obtained and matched with climate data from the warmer season (March to September) provided by the adjacent federal meteorological station of the German National Meteorological Service to calculate the relative risk of heat-associated preterm birth. Heat events were defined by ascending temperature percentiles in combination with humidity over exposure periods of up to 5 days. Further, ultrasound data documented in a longitudinal prospective pregnancy cohort study (n = 612) since 2012 were used to identify pathophysiological causes of heat-induced preterm birth. FINDINGS Both extreme heat and prolonged periods of heat exposure increased the relative risk of preterm birth (RR: 1.59; 95% CI: 1.01-2.43; p = 0.045; RR: 1.20; 95% CI: 1.02-1.40; p = 0.025). We identified a critical period of heat exposure during gestational ages 34-37 weeks that resulted in increased risk of late preterm birth (RR: 1.67; 95% CI: 1.14-1.43; p = 0.009). Pregnancies with a female fetus were more prone to heat stress-associated preterm birth. We found heat exposure was associated with altered vascular resistance within the uterine artery. INTERPRETATION Heat stress caused by high ambient temperatures increases the risk of preterm birth in a geographical region with temperate climate. Prenatal routine care should be revised in such regions to provide active surveillance for women at risk. FUNDING Found in acknowledgements.
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Affiliation(s)
- Dennis Yüzen
- Department of Obstetrics and Fetal Medicine, Laboratory for Experimental Feto-Maternal Medicine, University Medical Centre of Hamburg-Eppendorf, Germany; Institute of Immunology, University Medical Centre of Hamburg-Eppendorf, Germany
| | - Isabel Graf
- Department of Obstetrics and Fetal Medicine, Laboratory for Experimental Feto-Maternal Medicine, University Medical Centre of Hamburg-Eppendorf, Germany
| | - Ann-Christin Tallarek
- Department of Obstetrics and Fetal Medicine, University Medical Centre of Hamburg-Eppendorf, Germany
| | - Bettina Hollwitz
- Department of Obstetrics and Fetal Medicine, University Medical Centre of Hamburg-Eppendorf, Germany
| | - Christian Wiessner
- Institute of Medical Biometry and Epidemiology, University Medical Centre of Hamburg-Eppendorf, Germany
| | | | - Detlef Stammer
- Centre for Earth System Research and Sustainability (CEN), University Hamburg, Germany
| | - Amy Padula
- Division of Maternal-Fetal Medicine, Department of Obstetrics, University of California, San Francisco, USA
| | - Kurt Hecher
- Department of Obstetrics and Fetal Medicine, University Medical Centre of Hamburg-Eppendorf, Germany
| | - Petra Clara Arck
- Department of Obstetrics and Fetal Medicine, Laboratory for Experimental Feto-Maternal Medicine, University Medical Centre of Hamburg-Eppendorf, Germany.
| | - Anke Diemert
- Department of Obstetrics and Fetal Medicine, University Medical Centre of Hamburg-Eppendorf, Germany
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12
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Huang M, Strickland MJ, Richards M, Warren JL, Chang HH, Darrow LA. Confounding by Conception Seasonality in Studies of Temperature and Preterm Birth: A Simulation Study. Epidemiology 2023; 34:439-449. [PMID: 36719763 PMCID: PMC10993929 DOI: 10.1097/ede.0000000000001588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Seasonal patterns of conception may confound acute associations between birth outcomes and seasonally varying exposures. We aim to evaluate four epidemiologic designs (time-stratified case-crossover, time-series, pair-matched case-control, and time-to-event) commonly used to study acute associations between ambient temperature and preterm births. METHODS We conducted simulations assuming no effect of temperature on preterm birth. We generated pseudo-birth data from the observed seasonal patterns of birth in the United States and analyzed them in relation to observed temperatures using design-specific seasonality adjustments. RESULTS Using the case-crossover approach (time-stratified by calendar month), we observed a bias (among 1,000 replicates) = 0.016 (Monte-Carlo standard error 95% CI: 0.015-0.018) in the regression coefficient for every 10°C increase in mean temperature in the warm season (May-September). Unbiased estimates obtained using the time-series approach required accounting for both the pregnancies-at-risk and their weighted probability of birth. Notably, adding the daily weighted probability of birth from the time-series models to the case-crossover models corrected the bias in the case-crossover approach. In the pair-matched case-control design, where the exposure period was matched on gestational window, we observed no bias. The time-to-event approach was also unbiased but was more computationally intensive than others. CONCLUSIONS Most designs can be implemented in a way that yields estimates unbiased by conception seasonality. The time-stratified case-crossover design exhibited a small positive bias, which could contribute to, but not fully explain, previously reported associations.
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Affiliation(s)
| | | | | | | | - Howard H. Chang
- Rollins School of Public Health, Emory University, Atlanta, GA
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13
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Xu W, Li D, Shao Z, You Y, Pan F, Lou H, Li J, Jin Y, Wu T, Pan L, An J, Xu J, Cheng W, Tao L, Lei Y, Huang C, Shu Q. The prenatal weekly temperature exposure and neonatal congenital heart disease: a large population-based observational study in China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:38282-38291. [PMID: 36580248 PMCID: PMC9797890 DOI: 10.1007/s11356-022-24396-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
We aim to explore the link between maternal weekly temperature exposure and CHD in offspring and identify the relative contributions from heat and cold and from moderate and extreme atmospheric temperature. From January 2019 to December 2020, newborns who were diagnosed with CHD by echocardiography in the Network Platform for Congenital Heart Disease (NPCHD) from 11 cities in eastern China were enrolled in the present study. We appraised the exposure lag response relationship between temperature and CHDs in the distributed lag nonlinear model and further probed the pooled estimates by multivariate meta-analysis. We further performed the exposure-response curves in extreme temperature (5th percentile for cold and 95th for hot events). We also delve into the cumulative risk ratios (CRRs) of temperature on CHDs in general and subgroups. In this study, 5904 of 983, 523 infants were diagnosed with CHDs. The temperature-CHD combination performed positive significance in two exposure windows, gestational weeks 10-16 and 26-31, and reached the maximum effect in the 28th week. Compared with extreme cold (5th, 6.14℃), these effects were higher in extreme heat (95th, 29.26℃). The cumulative exposure-response curve showed a steep nonlinear rise in the hot tail but showed non-significance at low temperatures. In this range, the CRRs of temperature showed an increment to a ceiling of 3.781 (95% CI: 1.460-10.723). The temperature- CHD curves for both sex groups showed a general growth trend. No statistical significance was observed between these two groups (P = 0.106). The cumulative effect of the temperature related CHD was significant in regions with lower education levels (maximum CRR was 9.282 (3.019-28.535)). A degree centigrade increase in temperature exposure was associated with the increment of CHD risk in the first and second trimesters, especially in extreme heat. Neonates born in lower education regions were more vulnerable to temperature-related CHDs.
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Affiliation(s)
- Weize Xu
- Department of Cardiac Surgery, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310000, China
| | - Die Li
- Department of Cardiac Surgery, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310000, China
| | - Zehua Shao
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, 450003, China
| | - Yanqin You
- Department of Obstetrics and Gynecology, First Medical Center of Chinese, PLA General Hospital, Beijing, 100853, China
| | - Feixia Pan
- Department of Cardiac Surgery, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310000, China
| | - Hongliang Lou
- Jinhua Maternal and Child Health Care Hospital, Jinhua, 321000, China
| | - Jing Li
- Jiaxing Maternity and Child Health Care Hospital, Jiaxing, 314000, China
| | - Yueqin Jin
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China
| | - Ting Wu
- Hangzhou Women's Hospital, Hangzhou, 310000, China
| | - Lulu Pan
- Wenzhou Guidance Center for Maternity and Child Health, Wenzhou, 325000, China
| | - Jing An
- Huzhou Maternity and Child Health Care Hospital, Huzhou, 313000, China
| | - Junqiu Xu
- Zhoushan Women and Children Hospital, Zhoushan, 316000, China
| | - Wei Cheng
- Ningbo Women and Children Hospital, Ningbo, 315000, China
| | - Linghua Tao
- Taizhou Women and Children's Hospital, Taizhou, 318000, China
| | - Yongliang Lei
- Lishui Maternity and Child Health Care Hospital, Lishui, 323000, China
| | - Chengyin Huang
- Quzhou Maternity and Child Health Care Hospital, Quzhou, 324000, China
| | - Qiang Shu
- Department of Cardiac Surgery, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310000, China.
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14
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Nyadanu SD, Tessema GA, Mullins B, Pereira G. Prenatal acute thermophysiological stress and spontaneous preterm birth in Western Australia, 2000-2015: A space-time-stratified case-crossover analysis. Int J Hyg Environ Health 2022; 245:114029. [PMID: 36049361 DOI: 10.1016/j.ijheh.2022.114029] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/03/2022] [Accepted: 08/20/2022] [Indexed: 10/15/2022]
Abstract
Epidemiologic evidence on acute heat and cold stress and preterm birth (PTB) is inconsistent and based on ambient temperature rather than a thermophysiological index. The aim of this study was to use a spatiotemporal thermophysiological index (Universal Thermal Climate Index, UTCI) to investigate prenatal acute heat and cold stress exposures and spontaneous PTB. We conducted a space-time-stratified case-crossover analysis of 15,576 singleton live births with spontaneous PTB between January 1, 2000 and December 31, 2015 in Western Australia. The association between UTCI and spontaneous PTB was examined with distributed lag nonlinear models and conditional quasi-Poisson regression. Relative to the median UTCI, there was negligible evidence for associations at the lower range of exposures (1st to 25th percentiles). We found positive associations in the 95th and 99th percentiles, which increased with increasing days of heat stress in the first week of delivery. The relative risk (RR) and 95% confidence interval (CI) for the immediate (delivery day) and cumulative short-term (up to six preceding days) exposures to heat stress (99th percentile, 31.2 °C) relative to no thermal stress (median UTCI, 13.8 °C) were 1.01 (95% CI: 1.01, 1.02) and 1.05 (95% CI: 1.04, 1.06), respectively. Elevated effect estimates for heat stress were observed for the transition season, the year 2005-2009, male infants, women who smoked, unmarried, ≤ 19 years old, non-Caucasians, and high socioeconomic status. Effect estimates for cold stress (1st percentile, 0.7 °C) were highest in the transition season, during 2005-2009, and for married, non-Caucasian, and high socioeconomic status women. Acute heat stress was associated with an elevated risk of spontaneous PTB with sociodemographic vulnerability. Cold stress was associated with risk in a few vulnerable subgroups. Awareness and mitigation strategies such as hydration, reducing outdoor activities, affordable heating and cooling systems, and climate change governance may be beneficial. Further studies with the UTCI are required.
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Affiliation(s)
- Sylvester Dodzi Nyadanu
- Curtin School of Population Health, Curtin University, Perth, Kent Street, Bentley, Western Australia, 6102, Australia; Education, Culture, and Health Opportunities (ECHO) Ghana, ECHO Research Group International, Aflao, Ghana.
| | - Gizachew Assefa Tessema
- Curtin School of Population Health, Curtin University, Perth, Kent Street, Bentley, Western Australia, 6102, Australia; School of Public Health, University of Adelaide, Adelaide, South Australia, 5000, Australia
| | - Ben Mullins
- Curtin School of Population Health, Curtin University, Perth, Kent Street, Bentley, Western Australia, 6102, Australia
| | - Gavin Pereira
- Curtin School of Population Health, Curtin University, Perth, Kent Street, Bentley, Western Australia, 6102, Australia; EnAble Institute, Curtin University, Perth, Kent Street, Bentley, Western Australia, 6102, Australia; Centre for Fertility and Health (CeFH), Norwegian Institute of Public Health, 0473, Oslo, Norway
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15
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Syed S, O’Sullivan TL, Phillips KP. Extreme Heat and Pregnancy Outcomes: A Scoping Review of the Epidemiological Evidence. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19042412. [PMID: 35206601 PMCID: PMC8874707 DOI: 10.3390/ijerph19042412] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 12/04/2022]
Abstract
Background: Extreme heat caused by climate change is a major public health concern, disproportionately affecting poor and racialized communities. Gestational heat exposure is a well-established teratogen in animal studies, with a growing body of literature suggesting human pregnancies are similarly at risk. Characterization of extreme heat as a pregnancy risk is problematic due to nonstandard definitions of heat waves, and variable study designs. To better focus future research in this area, we conducted a scoping review to assess the effects of extreme heat on pregnancy outcomes. Methods: A scoping review of epidemiological studies investigating gestational heat-exposure and published 2010 and 2020, was conducted with an emphasis on study design, gestational windows of sensitivity, adverse pregnancy outcomes and characterization of environmental temperatures. Results: A sample of 84 studies was identified, predominantly set in high-income countries. Preterm birth, birthweight, congenital anomalies and stillbirth were the most common pregnancy outcome variables. Studies reported race/ethnicity and/or socioeconomic variables, however these were not always emphasized in the analysis. Conclusion: Use of precise temperature data by most studies avoided pitfalls of imprecise, regional definitions of heat waves, however inconsistent study design, and exposure windows are a significant challenge to systematic evaluation of this literature. Despite the high risk of extreme heat events and limited mitigation strategies in the global south, there is a significant gap in the epidemiological literature from these regions. Greater consistency in study design and exposure windows would enhance the rigor of this field.
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16
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Yu X, Miao H, Zeng Q, Wu H, Chen Y, Guo P, Zhu Y. Associations between ambient heat exposure early in pregnancy and risk of congenital heart defects: a large population-based study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:7627-7638. [PMID: 34476711 DOI: 10.1007/s11356-021-16237-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/25/2021] [Indexed: 02/05/2023]
Abstract
Some epidemiological studies have confirmed the association between environmental factors and congenital heart defects (CHD). While the possibility that maternal ambient heat exposures are related to CHD has received little attention. Our study aims to investigate the association between maternal ambient extreme heat exposure early in pregnancy and the risk of CHD in offspring in China. We conducted a retrospective cohort study of 1,918,105 fetuses between 2 and 8 weeks after gestation from May to October in Guangdong, China, 2015-2019. The main heat exposure was defined as extreme heat events (EHE) by using the 90th (EHE90) or 95th (EHE95) percentile of the daily maximum temperature. For each EHE definition, we further defined four indicators: having EHE or not, frequency, duration, and cumulative days. We used the log-binomial regression models to calculate the prevalence ratios (PR) of CHD with 95% confidence intervals (CI) for the associations between CHD and EHE, adjusted for potentially confounding covariates. There are 1,918,105 infants included in the study, of which 9588 had CHD, with a prevalence rate of 499.9 per 100,000 (95% CI: 489.9, 509.8). We found that all EHE indicators were positively associated with the increased risks of overall CHD, some CHD classes (congenital malformations of cardiac septa, congenital malformations of great arteries, and congenital malformations of great arteries), and some CHD subtypes (atrial septal defect and patent ductus arteriosus). In addition, the PR yielded higher estimates when exposing to EHE95. For instance, the risk of suffering congenital malformations of great arteries was 1.548 (95% CI: 1.401, 1.712) for EHE90 exposure and 1.723 (95% CI: 1.565, 1.898) for EHE95 exposure, respectively. Our study demonstrated that EHE during 2-8 weeks postconception was associated with overall CHD in offspring, particularly atrial septal defects and patent ductus arteriosus. The associations strengthened with the extent and cumulative days of maternal exposure to EHE.
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Affiliation(s)
- Xiaolin Yu
- Department of Preventive Medicine, Shantou University Medical College, Shantou, 515041, China
| | - Huazhang Miao
- Department of Healthcare, Guangdong Women and Children Hospital, No. 521 Xingnan Road, Guangzhou, 511442, China
- School of Health Management, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Qinghui Zeng
- Department of Preventive Medicine, Shantou University Medical College, Shantou, 515041, China
| | - Haisheng Wu
- Department of Preventive Medicine, Shantou University Medical College, Shantou, 515041, China
| | - Yuliang Chen
- Department of Preventive Medicine, Shantou University Medical College, Shantou, 515041, China
| | - Pi Guo
- Department of Preventive Medicine, Shantou University Medical College, Shantou, 515041, China.
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou, 515041, China
| | - Yingxian Zhu
- Department of Healthcare, Guangdong Women and Children Hospital, No. 521 Xingnan Road, Guangzhou, 511442, China
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Cushing L, Morello-Frosch R, Hubbard A. Extreme heat and its association with social disparities in the risk of spontaneous preterm birth. Paediatr Perinat Epidemiol 2022; 36:13-22. [PMID: 34951022 DOI: 10.1111/ppe.12834] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 10/21/2021] [Accepted: 10/24/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND Climate change is increasing the frequency and intensity of heatwaves. Prior studies associate high temperature with preterm birth. OBJECTIVES We tested the hypotheses that acute exposure to extreme heat was associated with higher risk of live spontaneous preterm birth (≥20 and <37 completed weeks), and that risks were higher among people of colour and neighbourhoods with heat-trapping landcover or concentrated racialised economic disadvantage. METHODS We conducted a retrospective cohort study of people giving birth between 2007 and 2011 in Harris County, Texas (Houston metropolitan area) (n = 198,013). Exposures were daily ambient apparent temperature (ATmax in 5°C increments) and dry-bulb temperatures (Tmax and Tmin >historical [1971-2000] summertime 99th percentile) up to a week prior for each day of pregnancy. Survival analysis controlled for individual-level risk factors, secular and seasonal trends. We considered race/ethnicity, heat-trapping neighbourhood landcover and Index of Concentration at the Extremes as effect modifiers. RESULTS The frequency of preterm birth was 10.3%. A quarter (26.8%) of people were exposed to ATmax ≥40°C, and 22.8% were exposed to Tmax and Tmin >99th percentile while at risk. The preterm birth rate among the exposed was 8.9%. In multivariable models, the risk of preterm birth was 15% higher following extremely hot days (hazard ratio [HR] 1.15 (95% confidence interval [CI] 1.01, 1.30) for ATmax ≥40°C vs. <20°C; HR 1.15 (95% CI 1.02, 1.28) for Tmax and Tmin >99th percentile). Censoring at earlier gestational ages suggested stronger associations earlier in pregnancy. The risk difference associated with extreme heat was higher in neighbourhoods of concentrated racialised economic disadvantage. CONCLUSIONS Ambient heat was associated with spontaneous preterm birth, with stronger associations earlier in pregnancy and in racially and economically disadvantaged neighbourhoods, suggesting climate change may worsen existing social inequities in preterm birth rates.
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Affiliation(s)
- Lara Cushing
- Department of Environmental Health Sciences, Fielding School of Public Health, University of California, Los Angeles, California, USA
| | - Rachel Morello-Frosch
- Department of Environmental Science, Policy & Management, University of California, Berkeley, California, USA.,School of Public Health, University of California, Berkeley, California, USA
| | - Alan Hubbard
- School of Public Health, University of California, Berkeley, California, USA
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Jegasothy E, Randall DA, Ford JB, Nippita TA, Morgan GG. Maternal factors and risk of spontaneous preterm birth due to high ambient temperatures in New South Wales, Australia. Paediatr Perinat Epidemiol 2022; 36:4-12. [PMID: 34850413 DOI: 10.1111/ppe.12822] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/09/2021] [Accepted: 09/12/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Exposure to high ambient temperatures has been shown to increase the risk of spontaneous preterm birth. Determining which maternal factors increase or decrease this risk will inform climate adaptation strategies. OBJECTIVES This study aims to assess the risk of spontaneous preterm birth associated with exposure to ambient temperature and differences in this relationship between mothers with different health and demographic characteristics. METHODS We used quasi-Poisson distributed lag non-linear models to estimate the effect of high temperature-measured as the 95th percentile of daily minimum, mean and maximum compared with the median-on risk of spontaneous preterm birth (23-36 weeks of gestation) in pregnant women in New South Wales, Australia. We estimated the cumulative lagged effects of daily temperature and analyses on population subgroups to assess increased or decreased vulnerability to this effect. RESULTS Pregnant women (n = 916,678) exposed at the 95th percentile of daily mean temperatures (25ºC) had an increased risk of preterm birth (relative risk 1.14, 95% confidence interval 1.07, 1.21) compared with the median daily mean temperature (17℃). Similar effect sizes were seen for the 95th percentile of minimum and maximum daily temperatures compared with the median. This risk was slightly higher among women with diabetes, hypertension, chronic illness and women who smoked during pregnancy. CONCLUSIONS Higher temperatures increase the risk of preterm birth and women with pre-existing health conditions and who smoke during pregnancy are potentially more vulnerable to these effects.
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Affiliation(s)
- Edward Jegasothy
- The University of Sydney, Sydney School of Public Health, University Centre for Rural Health, Sydney, NSW, Australia.,The University of Sydney Northern Clinical School, Women and Babies Research, St Leonards, NSW, Australia.,NSW Ministry of Health, NSW Biostatistics Training Program, Sydney, NSW, Australia
| | - Deborah A Randall
- The University of Sydney Northern Clinical School, Women and Babies Research, St Leonards, NSW, Australia.,Northern Sydney Local Health District, Kolling Institute, St Leonards, NSW, Australia
| | - Jane B Ford
- The University of Sydney Northern Clinical School, Women and Babies Research, St Leonards, NSW, Australia.,Northern Sydney Local Health District, Kolling Institute, St Leonards, NSW, Australia
| | - Tanya A Nippita
- The University of Sydney Northern Clinical School, Women and Babies Research, St Leonards, NSW, Australia.,Northern Sydney Local Health District, Kolling Institute, St Leonards, NSW, Australia.,Northern Sydney Local Health District, Department of Obstetrics and Gynecology, Royal North Shore Hospital, Sydney, NSW, Australia
| | - Geoffrey G Morgan
- The University of Sydney, Sydney School of Public Health, University Centre for Rural Health, Sydney, NSW, Australia
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Liang Z, Yang Y, Yi J, Qian Z, Zhang Z, McMillin SE, Liu E, Lin H, Liu G. Maternal PM 2.5 exposure associated with stillbirth: A large birth cohort study in seven Chinese cities. Int J Hyg Environ Health 2021; 236:113795. [PMID: 34186502 DOI: 10.1016/j.ijheh.2021.113795] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 05/14/2021] [Accepted: 06/14/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Maternal exposure to fine particulate matter (PM2.5) has been associated with a few adverse birth outcomes. However, its effect on stillbirth remains unknown in China, especially the susceptible windows and potential modifiers. OBJECTIVE This study aimed to evaluate the associations between maternal PM2.5 exposure and stillbirth in seven Chinese cities. METHODS We used birth cohort data of 1,273,924 mother-and-birth pairs in seven cities in southern China between 2014 and 2017 to examine these associations. Pregnant women were recruited in the cohort at their first visit to a doctor for pregnancy, and stillbirths were recorded at the time of birth. Air pollution exposures were assessed through linking daily air pollutant concentrations from nearby monitoring stations to the mother's residential community. Cox regression models were applied to determine the associations between PM2.5 and stillbirth for different gestational periods. RESULTS Among the participants, 3150 (2.47‰) were identified as stillbirth cases. The hazard ratio (HR) of stillbirths was 1.52 (95% CI: 1.42, 1.62) for each 10 μg/m3 increase in PM2.5 during the entire pregnancy after controlling for some important covariates. Relatively stronger associations were observed during the second trimester [adjusted HR = 1.67 (95% CI: 1.57, 1.77)] than trimesters 1 [HR = 1.44 (95% CI: 1.37, 1.52)] and trimester 3 [HR = 1.23 (95% CI: 1.16, 1.30)]. Stratified analyses also showed a stronger association among pregnant women without previous pregnancy and previous delivery experiences. CONCLUSION The study indicates that maternal exposure to PM2.5, especially during the midpoint period of pregnancy, might increase the risk of stillbirths. Maternal previous pregnancy and delivery may modify this association.
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Affiliation(s)
- Zhijiang Liang
- Department of Public Health, Guangdong Women and Children Hospital, 521 Xingnan Road, Panyu District, Guangzhou, 511442, China
| | - Yin Yang
- Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Jing Yi
- Department of Obstetrics, Guangdong Women and Children Hospital, 521 Xingnan Road, Panyu District, Guangzhou, 511442, China
| | - Zhengmin Qian
- Department of Epidemiology and Biostatistics, College for Public Health & Social Justice, Saint Louis University, Saint Louis, MO, 63104, USA
| | - Zilong Zhang
- Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Stephen Edward McMillin
- School of Social Work, College for Public Health & Social Justice, Saint Louis University, St. Louis, MO, 63103, USA
| | - Echu Liu
- Department of Health Management and Policy, College for Public Health and Social Justice, Saint Louis University, Saint Louis, MO, 63104, USA
| | - Hualiang Lin
- Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China.
| | - Guocheng Liu
- Department of Obstetrics, Guangdong Women and Children Hospital, 521 Xingnan Road, Panyu District, Guangzhou, 511442, China.
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20
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Huang M, Strickland MJ, Richards M, Holmes HA, Newman AJ, Garn JV, Liu Y, Warren JL, Chang HH, Darrow LA. Acute associations between heatwaves and preterm and early-term birth in 50 US metropolitan areas: a matched case-control study. Environ Health 2021; 20:47. [PMID: 33892728 PMCID: PMC8066488 DOI: 10.1186/s12940-021-00733-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND The effect of heatwaves on adverse birth outcomes is not well understood and may vary by how heatwaves are defined. The study aims to examine acute associations between various heatwave definitions and preterm and early-term birth. METHODS Using national vital records from 50 metropolitan statistical areas (MSAs) between 1982 and 1988, singleton preterm (< 37 weeks) and early-term births (37-38 weeks) were matched (1:1) to controls who completed at least 37 weeks or 39 weeks of gestation, respectively. Matching variables were MSA, maternal race, and maternal education. Sixty heatwave definitions including binary indicators for exposure to sustained heat, number of high heat days, and measures of heat intensity (the average degrees over the threshold in the past 7 days) based on the 97.5th percentile of MSA-specific temperature metrics, or the 85th percentile of positive excessive heat factor (EHF) were created. Odds ratios (OR) for heatwave exposures in the week preceding birth (or corresponding gestational week for controls) were estimated using conditional logistic regression adjusting for maternal age, marital status, and seasonality. Effect modification by maternal education, age, race/ethnicity, child sex, and region was assessed. RESULTS There were 615,329 preterm and 1,005,576 early-term case-control pairs in the analyses. For most definitions, exposure to heatwaves in the week before delivery was consistently associated with increased odds of early-term birth. Exposure to more high heat days and more degrees above the threshold yielded higher magnitude ORs. For exposure to 3 or more days over the 97.5th percentile of mean temperature in the past week compared to zero days, the OR was 1.027 for early-term birth (95%CI: 1.014, 1.039). Although we generally found null associations when assessing various heatwave definitions and preterm birth, ORs for both preterm and early-term birth were greater in magnitude among Hispanic and non-Hispanic black mothers. CONCLUSION Although associations varied across metrics and heatwave definitions, heatwaves were more consistently associated with early-term birth than with preterm birth. This study's findings may have implications for prevention programs targeting vulnerable subgroups as climate change progresses.
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Affiliation(s)
- Mengjiao Huang
- School of Community Health Sciences, University of Nevada, 1664 N. Virginia Street, Reno, NV, 89557, USA.
| | - Matthew J Strickland
- School of Community Health Sciences, University of Nevada, 1664 N. Virginia Street, Reno, NV, 89557, USA
| | - Megan Richards
- School of Community Health Sciences, University of Nevada, 1664 N. Virginia Street, Reno, NV, 89557, USA
| | - Heather A Holmes
- Department of Chemical Engineering, University of Utah, Salt Lake City, UT, USA
| | | | - Joshua V Garn
- School of Community Health Sciences, University of Nevada, 1664 N. Virginia Street, Reno, NV, 89557, USA
| | - Yan Liu
- School of Community Health Sciences, University of Nevada, 1664 N. Virginia Street, Reno, NV, 89557, USA
| | - Joshua L Warren
- Department of Biostatistics, Yale University, New Haven, CT, USA
| | - Howard H Chang
- Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Lyndsey A Darrow
- School of Community Health Sciences, University of Nevada, 1664 N. Virginia Street, Reno, NV, 89557, USA
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21
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Olivier K, Reinders LA, Clarke MW, Crew RC, Pereira G, Maloney SK, Wyrwoll CS. Maternal, Placental, and Fetal Responses to Intermittent Heat Exposure During Late Gestation in Mice. Reprod Sci 2021; 28:416-425. [PMID: 32804351 DOI: 10.1007/s43032-020-00291-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 08/06/2020] [Indexed: 11/30/2022]
Abstract
Physiological adaptations during heat exposure are critical in pregnancy. Maternal thermoregulation has to accommodate the increased metabolic load of the developing fetus. Here, we assess the consequences of intermittent heat exposure, as occurs in heat waves, for maternal adaptations during pregnancy, and chronic feto-placental outcomes. Following timed mating, C57BL/6J mice were allocated to either standard animal housing temperature conditions (SH) or housing at a temperature within the thermoneutral zone (TNZ). A subset of the TNZ group was exposed to 37 °C for 8 h a day from E15.5 to E17.5 to simulate a heat wave (HW). Maternal weight gain, food intake, rectal temperature, and nesting behaviors were measured across gestation. Fetal and placental tissues were collected at E18.5. With heat exposure, maternal rectal temperature increased while food intake and nest complexity decreased. Maternal daily weight gain initially decreased due to heat exposure, but on the last day of exposure, it was comparable to the other experimental groups. These maternal responses during heat exposure impacted on the fetus, with restrictions in placental and fetal development evident just before birth. Thus, the vascular portion of the placenta, and the relative fetal head size, was smaller. Furthermore, SH and TNZ animals demonstrated distinct differences in food intake and nesting behavior during pregnancy, reinforcing the need for caution in extrapolating from animal models to humans when housing occurs outside of thermoneutral zone conditions. This study highlights the direct effects of temperature conditions on health in pregnancy and provides a foundation for future studies to investigate fetal health consequences that are associated with intermittent heat exposure.
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Affiliation(s)
- Karike Olivier
- School of Human Sciences, The University of Western Australia, Perth, 6009, Australia
| | - Lauren A Reinders
- School of Human Sciences, The University of Western Australia, Perth, 6009, Australia
| | - Michael W Clarke
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, 6009, Australia
| | - Rachael C Crew
- School of Human Sciences, The University of Western Australia, Perth, 6009, Australia
| | - Gavin Pereira
- School of Public Health, Curtin University, Bentley, 6102, Australia
| | - Shane K Maloney
- School of Human Sciences, The University of Western Australia, Perth, 6009, Australia
| | - Caitlin S Wyrwoll
- School of Human Sciences, The University of Western Australia, Perth, 6009, Australia.
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Mayvaneh F, Entezari A, Sadeghifar F, Baaghideh M, Guo Y, Atabati A, Zhao Q, Zhang Y. Exposure to suboptimal ambient temperature during specific gestational periods and adverse outcomes in mice. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:45487-45498. [PMID: 32789805 DOI: 10.1007/s11356-020-10416-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
Exposure to suboptimal ambient temperature during pregnancy has been reported as a potential teratogen of fetal development. However, limited animal evidence is available regarding the impact of extreme temperatures on maternal pregnancy and the subsequent adverse pregnancy outcomes. Our objective in this study is to investigate the relationship between temperature and maternal stress during pregnancy in mice. This study used the Naval Medical Research Institute (NMRI) mice during the second and third pregnant weeks with the gestational day (GD) (GD 6.5-14.5 and GD 14.5-17.5). Mice were exposed to suboptimal ambient temperature (1 °C, 5 °C, 10 °C, 15 °C, 40 °C, 42 °C, 44 °C, 46 °C, and 48 °C for the experimental group and 23 °C for the control group) 1 h per day, 7 days a weekin each trimester. Measurements of placental development (placental weight [PW] and placental diameter [PD]) and fetal growth (fetal weight [FW] and crown-to-rump length [CRL]) between experimental and control groups were compared using analysis of variance (ANOVA). Data on the occurrence of preterm birth (PTB) and abnormalities were also collected. The results showed that exposure to both cold and heat stress in the second and third weeks of pregnancy caused significant decreases in measurements of placental development (PW and PD) and fetal growth (FW and CRL). For all temperature exposures, 15 °C was identified as the optimal temperature in the development of the embryo. Most PTB occurrences were observed in high-temperature stress groups, with the highest PTB number seen in the exposure group at 48 °C, whereas PTB occurred only at 1 °C among cold stress groups. In the selected exposure experiments, an approximate U-shaped relation was observed between temperature and number of abnormality occurrence. The highest percentage of these anomalies occurred at temperatures of 1 °C and 48 °C, while no abnormalities were observed at 15 °C and in the control group. Our findings strengthened the evidence that exposure to suboptimal ambient temperatures may trigger adverse pregnancy outcomes and worsen embryo and fetal development in mice.
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Affiliation(s)
- Fatemeh Mayvaneh
- Faculty of Geography and Environmental Sciences, Hakim Sabzevari University, Khorasan Razavi, Sabzevar, 9617916487, Iran
| | - Alireza Entezari
- Faculty of Geography and Environmental Sciences, Hakim Sabzevari University, Khorasan Razavi, Sabzevar, 9617916487, Iran.
| | - Fatemeh Sadeghifar
- Department of Science, Hakim Sabzevari University, Khorasan Razavi, Sabzevar, 9617916487, Iran
| | - Mohammad Baaghideh
- Faculty of Geography and Environmental Sciences, Hakim Sabzevari University, Khorasan Razavi, Sabzevar, 9617916487, Iran
| | - Yuming Guo
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
| | - Azadeh Atabati
- Faculty of Geography and Environmental Sciences, Hakim Sabzevari University, Khorasan Razavi, Sabzevar, 9617916487, Iran
| | - Qi Zhao
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
| | - Yunquan Zhang
- Department of Epidemiology and Biostatistics, School of Public Health, Medical College, Wuhan University of Science and Technology, Wuhan, 430065, China.
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, 430065, China.
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23
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Chersich MF, Pham MD, Areal A, Haghighi MM, Manyuchi A, Swift CP, Wernecke B, Robinson M, Hetem R, Boeckmann M, Hajat S. Associations between high temperatures in pregnancy and risk of preterm birth, low birth weight, and stillbirths: systematic review and meta-analysis. BMJ 2020; 371:m3811. [PMID: 33148618 PMCID: PMC7610201 DOI: 10.1136/bmj.m3811] [Citation(s) in RCA: 153] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To assess whether exposure to high temperatures in pregnancy is associated with increased risk for preterm birth, low birth weight, and stillbirth. DESIGN Systematic review and random effects meta-analysis. DATA SOURCES Medline and Web of Science searched up to September 2018, updated in August 2019. ELIGIBILITY CRITERIA FOR SELECTING STUDIES Clinical studies on associations between high environmental temperatures, and preterm birth, birth weight, and stillbirths. RESULTS 14 880 records and 175 full text articles were screened. 70 studies were included, set in 27 countries, seven of which were countries with low or middle income. In 40 of 47 studies, preterm births were more common at higher than lower temperatures. Exposures were classified as heatwaves, 1°C increments, and temperature threshold cutoff points. In random effects meta-analysis, odds of a preterm birth rose 1.05-fold (95% confidence interval 1.03 to 1.07) per 1°C increase in temperature and 1.16-fold (1.10 to 1.23) during heatwaves. Higher temperature was associated with reduced birth weight in 18 of 28 studies, with considerable statistical heterogeneity. Eight studies on stillbirths all showed associations between temperature and stillbirth, with stillbirths increasing 1.05-fold (1.01 to 1.08) per 1°C rise in temperature. Associations between temperature and outcomes were largest among women in lower socioeconomic groups and at age extremes. The multiple temperature metrics and lag analyses limited comparison between studies and settings. CONCLUSIONS Although summary effect sizes are relatively small, heat exposures are common and the outcomes are important determinants of population health. Linkages between socioeconomic status and study outcomes suggest that risks might be largest in low and middle income countries. Temperature rises with global warming could have major implications for child health. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD 42019140136 and CRD 42018118113.
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Affiliation(s)
- Matthew Francis Chersich
- Wits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Hillbrow, Johannesburg 2001, South Africa
| | - Minh Duc Pham
- Burnet Institute, Melbourne, VIC, Australia
- School of Public Health and Preventive Medicine, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Ashtyn Areal
- Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Marjan Mosalam Haghighi
- The Children's Hospital at Westmead, Cardiology Centre, University of Sydney, Sydney, NSW, Australia
| | - Albert Manyuchi
- Global Change Institute, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Bianca Wernecke
- Environment and Health Research Unit, South African Medical Research Council, Johannesburg, South Africa
- Environmental Health Department, Faculty of Health Sciences, University of Johannesburg, South Africa
| | | | - Robyn Hetem
- School of Animal, Plant and Environmental Sciences, Faculty of Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Melanie Boeckmann
- Department of Environment and Health, School of Public Health, Bielefeld University, Germany
| | - Shakoor Hajat
- Department of Public Health, Environments and Society, and the Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
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Sun Y, Ilango SD, Schwarz L, Wang Q, Chen JC, Lawrence JM, Wu J, Benmarhnia T. Examining the joint effects of heatwaves, air pollution, and green space on the risk of preterm birth in California. ENVIRONMENTAL RESEARCH LETTERS : ERL [WEB SITE] 2020; 15:104099. [PMID: 34659452 PMCID: PMC8516119 DOI: 10.1088/1748-9326/abb8a3] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
BACKGROUND Exposure to high air temperature in late pregnancy is increasingly recognized as a risk factor for preterm birth (PTB). However, the combined effects of heatwaves with air pollution and green space are still unexplored. In the context of climate change, investigating the interaction between environmental factors and identifying communities at higher risk is important to better understand the etiological mechanisms and design targeted interventions towards certain women during pregnancy. OBJECTIVES To examine the combined effects of heatwaves, air pollution and green space exposure on the risk of PTB. METHODS California birth certificate records for singleton births (2005-2013) were obtained. Residential zip code-specific daily temperature during the last week of gestation was used to create 12 definitions of heatwave with varying temperature thresholds and durations. We fit multi-level Cox proportional hazard models with time to PTB as the outcome and gestational week as the temporal unit. Relative risk due to interaction (RERI) was applied to estimate the additive interactive effect of air pollution and green space on the effect of heatwaves on PTB. RESULTS In total, 1,967,300 births were included in this study. For PM2.5, PM10 and O3, we found positive additive interactions (RERIs >0) between heatwaves and higher air pollution levels. Combined effects of heatwaves and green space indicated negative interactions (RERIs <0) for less intense heatwaves (i.e., shorter duration or relatively low temperature), whereas there were potential positive interactions (RERIs >0) for more intense heatwaves. CONCLUSION This study found synergistic harmful effects for heatwaves with air pollution, and potential positive interactions with lack of green space on PTB. Implementing interventions, such as heat warning systems and behavioral changes, targeted toward pregnant women at risk for high air pollution and low green space exposures may optimize the benefits of reducing acute exposure to extreme heat before delivery.
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Affiliation(s)
- Yi Sun
- Department of Environmental and Occupational Health, University of California, Irvine, CA 92697-3957, USA
| | - Sindana D. Ilango
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA 92093, USA
- School of Public Health, San Diego State University, San Diego, CA, 92182, USA
| | - Lara Schwarz
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA 92093, USA
- School of Public Health, San Diego State University, San Diego, CA, 92182, USA
| | - Qiong Wang
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Jiu-Chiuan Chen
- Department of Preventive Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Jean M. Lawrence
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
| | - Jun Wu
- Department of Environmental and Occupational Health, University of California, Irvine, CA 92697-3957, USA
- Program in Public Health, 653 East Peltason Drive, University of California, Irvine CA 92697-3957, USA
| | - Tarik Benmarhnia
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA 92093, USA
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, 92037, USA
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Association of Summer Heat Waves and the Probability of Preterm Birth in Minnesota: An Exploration of the Intersection of Race and Education. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17176391. [PMID: 32887349 PMCID: PMC7503599 DOI: 10.3390/ijerph17176391] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/24/2020] [Accepted: 08/28/2020] [Indexed: 11/17/2022]
Abstract
Preterm birth (PTB) is common and has negative impacts on infant health. While some maternal risk factors have been identified, including age under 20 or over 40, substance abuse, low BMI, and racism, less is known about the impact of environmental exposures like high heat. We combined 154,157 records of live births occurring in Minnesota between 2009 and 2015 with hourly weather records collected from the Minneapolis–St. Paul airport. We tested if maternal heat wave exposure (a seven-day period with a mean daily high temp of 37 °C) immediately prior to birth leads to a higher risk of preterm birth. Additional covariates included maternal age, race/ethnicity, educational status, and residence in the seven-county Minneapolis–St. Paul metro area. Pregnant women exposed to a seven-day heat wave of 37 °C or higher experienced a higher relative risk of PTB compared to women who did not experience a heat wave (1.14 risk ratio (RR), 1.0–1.3 95% confidence interval (CI)). The result is robust to controls for a woman’s age, race/ethnicity, educational attainment, place of residence, and year of the birth. Children born to Black women with college degrees who are exposed to heat waves experience a higher relative risk of PTB compared to White women with college degrees in a heat wave (2.97 RR, 1.5–6.1 95% CI). Summer heat waves are associated with higher risk of PTB in late-term pregnancies in Minnesota.
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Spolter F, Kloog I, Dorman M, Novack L, Erez O, Raz R. Prenatal exposure to ambient air temperature and risk of early delivery. ENVIRONMENT INTERNATIONAL 2020; 142:105824. [PMID: 32603968 PMCID: PMC7537740 DOI: 10.1016/j.envint.2020.105824] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/01/2020] [Accepted: 05/18/2020] [Indexed: 05/09/2023]
Abstract
BACKGROUND Preterm birth is a major determinant of adverse health consequences, and early term births are also associated with increased risk of various outcomes. In light of climate change, the effect of ambient temperature on earlier delivery is an important factor to consider. Several studies have focused on associations of ambient air temperature (Ta) on preterm birth, but few have examined associations with early term births. AIMS To investigate the association of prenatal exposure to Ta with preterm birth (<37 completed gestation weeks) and with early-term birth (<39 completed gestation weeks) in a semi-arid climate. METHODS All singleton deliveries at the Soroka Medical Center from the Southern district of Israel, with estimated conception dates between May 1, 2004 and March 31, 2013 (N = 62,547) were linked to prenatal Ta estimates from a spatiotemporally resolved model, with daily 1 km resolution. We used time-dependent Cox regression models with weekly mean Ta throughout gestation, adjusted for calendar month and year of conception, ethnicity, census-level socio-economic status and population density. RESULTS Ta was positively associated with late preterm birth (31 + 0/7 - 36 + 6/7 weeks), with increased risk in the upper Ta quintile as compared to the third quintile, hazard ratio (HR) = 1.31, 95% confidence interval (CI) = 1.11-1.56. Ta also associated with early term birth (37 + 0/6 - 38 + 6/7), with increased risk in the upper Ta quintile as compared to the third quintile, HR = 1.24, 95% CI = 1.13-1.36. CONCLUSION Exposure to high ambient temperature during pregnancy is associated with a higher risk of preterm and early term birth in southern Israel.
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Affiliation(s)
- Faige Spolter
- Braun School of Public Health and Community Medicine, The Hebrew University of Jerusalem, Israel
| | - Itai Kloog
- The Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Israel
| | - Michael Dorman
- The Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Israel
| | - Lena Novack
- Soroka University Medical Center, Israel, Ben-Gurion University of the Negev, Israel
| | - Offer Erez
- Division of Obstetrics and Gynecology, Soroka University Medical Center, Israel, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel, Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, USA
| | - Raanan Raz
- Braun School of Public Health and Community Medicine, The Hebrew University of Jerusalem, Israel.
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27
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Affiliation(s)
- Dolores Malaspina
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York.,Blavatnik Family Women's Health Research Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Elizabeth A Howell
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York.,Blavatnik Family Women's Health Research Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Julie Spicer
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York.,Blavatnik Family Women's Health Research Institute, Icahn School of Medicine at Mount Sinai, New York, New York
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A population-based case-control study of the association between weather-related extreme heat events and low birthweight. J Dev Orig Health Dis 2020; 12:335-342. [PMID: 32468978 DOI: 10.1017/s2040174420000392] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Although prenatal exposure to high ambient temperatures were reported to be associated with preterm birth, limited research assessed the impact of weather-related extreme heat events (EHE) on birthweight, particularly by trimester. We, therefore, investigated the impact of prenatal EHE on birthweight among term babies (tLBW) by trimester and birthweight percentile. We conducted a population-based case-control study on singleton live births at 38-42 gestational weeks in New York State (NYS) by linking weather data with NYS birth certificates. A total of 22,615 cases were identified as birthweight <2500 gram, and a random sample of 139,168 normal birthweight controls was included. EHE was defined as three consecutive days with the maximum temperatures of ≥32.2 °C/90 °F (EHE90) and two consecutive days of temperatures ≥97th percentile (EHE97) based on the distribution of the maximum temperature for the season and region. We estimated odds ratios (ORs) and 95% confidence intervals (95% CI) with multivariable unconditional logistic regression, controlling for confounders. Overall exposure to EHE97 for 2 d was associated with tLBW (OR 1.05; 95% CI 1.02, 1.09); however, the strongest associations were only observed in the first trimester for both heat indicators, especially when exposure was ≥3 d (ORs ranged: 1.06-1.13). EHE in the first trimester was associated with significant reduction in mean birthweight from 26.78 gram (EHE90) to 36.25 gram (EHE97), which mainly affected the 40th and 60th birthweight percentiles. Findings revealed associations between multiple heat indicators and tLBW, where the impact was consistently strongest in the first trimester.
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Ilango SD, Weaver M, Sheridan P, Schwarz L, Clemesha RES, Bruckner T, Basu R, Gershunov A, Benmarhnia T. Extreme heat episodes and risk of preterm birth in California, 2005-2013. ENVIRONMENT INTERNATIONAL 2020; 137:105541. [PMID: 32059147 DOI: 10.1016/j.envint.2020.105541] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 01/16/2020] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Preterm birth is a leading cause of infant morbidity and mortality. Identifying potentially modifiable triggers toward the end of gestation, such as extreme heat, can improve understanding of the role of acute stress on early deliveries and inform warning systems. In this study we examined the association between extreme heat, variously defined during the last week of gestation, and risk of preterm birth among mothers in California. METHODS We created a population-based cohort comprised of 1,967,300 mothers who had live, singleton births in California, from May through September 2005-2013. Daily temperature data estimated at the maternal zip code of residence was used to create 12 definitions of extreme heat with varying relative temperatures (75th, 90th, 95th, and 98th percentiles) and durations (at least 2, 3, or 4 consecutive days). We estimated risk of preterm birth (<37 gestational weeks) in relation to exposure to extreme heat during the last week of gestation with multi-level Cox proportional hazard regression models, adjusting for maternal characteristics, sex of neonate, and seasonality. We also included randomly generated data, SAS code, and estimates for reproducibility purposes. RESULTS Approximately 7% of the cohort had a preterm birth. For all definitions of extreme heat, the risk of preterm birth was consistently higher among mothers who experienced an extreme heat episode during their last week of gestation. Hazard ratios ranged from 1.008 (95% CI: 0.997, 1.021) to 1.128 (95% CI: 1.052, 1.210), with increasing associations as the relative temperature and duration of extreme heat episode increased. CONCLUSION This study adds to the previous literature by considering multiple definitions of extreme heat and applying a time-to-event framework. Findings suggest that acute exposure to extreme heat during the last week of gestation may trigger an earlier delivery. Implementing heat warning systems targeted toward pregnant women may improve birth outcomes.
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Affiliation(s)
- Sindana D Ilango
- School of Public Health, San Diego State University, San Diego, CA, United States; Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, United States.
| | - Meschelle Weaver
- Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, United States
| | - Paige Sheridan
- School of Public Health, San Diego State University, San Diego, CA, United States; Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, United States
| | - Lara Schwarz
- School of Public Health, San Diego State University, San Diego, CA, United States; Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, United States
| | - Rachel E S Clemesha
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, United States
| | - Tim Bruckner
- Program in Public Health, UC Irvine, Irvine, CA, United States
| | - Rupa Basu
- Office of Environmental Hazard Assessment, California Environmental Protection Agency, Oakland, CA, United States
| | - Alexander Gershunov
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, United States
| | - Tarik Benmarhnia
- Department of Family Medicine and Public Health, UC San Diego, La Jolla, CA, United States; Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, United States
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Bonell A, Hirst J, Vicedo-Cabrera AM, Haines A, Prentice AM, Maxwell NS. A protocol for an observational cohort study of heat strain and its effect on fetal wellbeing in pregnant farmers in The Gambia. Wellcome Open Res 2020; 5:32. [PMID: 32292825 PMCID: PMC7141168 DOI: 10.12688/wellcomeopenres.15731.2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2020] [Indexed: 11/20/2022] Open
Abstract
Introduction: Climate change predictions indicate that global temperatures are likely to exceed those seen in the last 200,000 years, rising by around 4°C above pre-industrial levels by 2100 (without effective mitigation of current emission rates). In regions of the world set to experience extreme temperatures, women often work outside in agriculture even during pregnancy. The implications of heat strain in pregnancy on maternal health and pregnancy outcome are not well understood. This protocol describes a study to assess the physiological response of pregnant women to environmental heat stress and the immediate effect this has on fetal wellbeing. Methods and analysis: The study will be performed in West Kiang district, The Gambia; a semi-arid zone in West Africa with daily maximum temperatures ranging from approximately 32 to 40°C. We will recruit 125 pregnant women of all ages who perform agricultural work during their pregnancy. Participants will be followed every two months until delivery. At each study visit fetal growth will be measured by ultrasound scan. During the course of their working day we will take the following measurements: continuous maternal physiological measurements (heart rate, respiratory rate, chest skin temperature and tri-axis accelerometer data); intermittent maternal tympanic core temperature, four point skin temperature, blood pressure; intermittent fetal heart rate and, if eligible, umbilical artery doppler; intermittent environmental measurements of air temperature, humidity, solar radiation and wind speed. Venous blood and urine will be collected at beginning and end of day for biomarkers of heat strain or fetal distress and hydration status.
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Affiliation(s)
- Ana Bonell
- Medical Research Council Gambia @ London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Jane Hirst
- Nuffield Department of Women's and Reproductive Health and the George Institute for Global Health, University of Oxford, Oxford, UK
| | - Ana M Vicedo-Cabrera
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.,Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
| | - Andy Haines
- Department of Public Health, Environment and Society; Department of Population health, London School of Hygiene and Tropical Medicine, London, UK
| | - Andrew M Prentice
- Medical Research Council Gambia @ London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Neil S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Brighton, UK
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Bonell A, Hirst J, Vicedo-Cabrera AM, Haines A, Prentice AM, Maxwell NS. A protocol for an observational cohort study of heat strain and its effect on fetal wellbeing in pregnant farmers in The Gambia. Wellcome Open Res 2020; 5:32. [PMID: 32292825 PMCID: PMC7141168 DOI: 10.12688/wellcomeopenres.15731.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2020] [Indexed: 11/15/2023] Open
Abstract
Introduction: Climate change predictions indicate that global temperatures are likely to exceed those seen in the last 200,000 years, rising by around 4°C above pre-industrial levels by 2100 (without effective mitigation of current emission rates). In regions of the world set to experience extreme temperatures, women often work outside in agriculture even during pregnancy. The implications of heat strain in pregnancy on maternal health and pregnancy outcome are not well understood. This protocol describes a study to assess the physiological response of pregnant women to environmental heat stress and the immediate effect this has on fetal wellbeing. Methods and analysis: The study will be performed in West Kiang district, The Gambia; a semi-arid zone in West Africa with daily maximum temperatures ranging from approximately 32 to 40°C. We will recruit 125 pregnant women of all ages who perform agricultural work during their pregnancy. Participants will be followed every two months until delivery. At each study visit fetal growth will be measured by ultrasound scan. During the course of their working day we will take the following measurements: continuous maternal physiological measurements (heart rate, respiratory rate, chest skin temperature and tri-axis accelerometer data); intermittent maternal tympanic core temperature, four point skin temperature, blood pressure; intermittent fetal heart rate and, if eligible, umbilical artery doppler; intermittent environmental measurements of air temperature, humidity, solar radiation and wind speed. Venous blood and urine will be collected at beginning and end of day for biomarkers of heat strain or fetal distress and hydration status.
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Affiliation(s)
- Ana Bonell
- Medical Research Council Gambia @ London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Jane Hirst
- Nuffield Department of Women's and Reproductive Health and the George Institute for Global Health, University of Oxford, Oxford, UK
| | - Ana M. Vicedo-Cabrera
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
| | - Andy Haines
- Department of Public Health, Environment and Society; Department of Population health, London School of Hygiene and Tropical Medicine, London, UK
| | - Andrew M. Prentice
- Medical Research Council Gambia @ London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, University of Brighton, Brighton, UK
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Liu X, Xiao J, Sun X, Chen Q, Yao Z, Feng B, Cao G, Guo L, He G, Hu J, Zeng W, Rong Z, Wang Q, Zhang B, Dong M, Wang J, Chen D, Ma W, Liu T. Associations of maternal ambient temperature exposures during pregnancy with the risk of preterm birth and the effect modification of birth order during the new baby boom: A birth cohort study in Guangzhou, China. Int J Hyg Environ Health 2020; 225:113481. [PMID: 32058935 DOI: 10.1016/j.ijheh.2020.113481] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/28/2020] [Accepted: 02/03/2020] [Indexed: 10/25/2022]
Abstract
Maternal exposures to ambient temperatures during pregnancy may increase the preterm birth (PTB) risk; however, which periods have stronger effects remain controversial. The effects of temperature exposure on PTB in first- and second-born neonate groups may be different during the new baby boom that has followed the Two-child Policy in China. We examined a birth cohort of 4928 pregnant women beginning in 2016 in Guangzhou, China. An inverse distance weighted method was used to estimate the temperature exposure at each individual residential address. A distribution lag non-linear model incorporating a Cox proportional hazard model was employed to estimate the effects of temperature exposure on PTB and test the effects modification of birth order related to the new baby boom. A total of 4101 pregnant women were included, of which 234 (5.7%) experienced PTB. Compared with the mean temperature (23.0 °C), we found a significantly higher risks of PTB associated with high temperatures (i.e, 30 °C [95th centile]) from the 4th to 8th, and 22nd to 27th gestational weeks. A peak effect was found during the 6th week (HR = 1.79, 95% CI: 1.26, 2.54) and 24th week (HR = 1.83, 95% CI: 1.27, 2.62). The risks of PTB were reduced for low temperatures (i.e. 14 °C [5th centile] versus 23.0 °C) from the 2nd to 10th and 20th to 26th gestational weeks, and the negative peak effect was found during the 4th week (HR = 0.43, 95% CI: 0.26, 0.72) and 23rd week (HR = 0.59, 95% CI: 0.43, 0.83). Stratification analyses showed that significant effects of 30 °C versus 23 °C on PTB were observed during the 4th to 8th weeks in the second-born neonate, and the peak effect was found in the 6th week (HR = 2.13, 95% CI: 1.31, 3.47). However, we did not find significant effects of 30 °C during the same weeks in the first-born neonate group. Maternal exposures to higher temperatures during pregnancy may increase the risk of PTB, and lower temperatures may decrease the risk of PTB. Stronger effects of temperature exposures during the first trimester on PTB risk were found among the second-born neonates than among the first-born neonates.
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Affiliation(s)
- Xin Liu
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, 510080, China; Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Jianpeng Xiao
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Xiaoli Sun
- Gynecology Department, Guangdong Women and Children Hospital, Guangzhou, 511442, China
| | - Qingsong Chen
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, 510080, China
| | - Zhenjiang Yao
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, 510080, China
| | - Baixiang Feng
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Ganxiang Cao
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Lingchuan Guo
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Guanhao He
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Jianxiong Hu
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Weilin Zeng
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Zuhua Rong
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Qiong Wang
- School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Bo Zhang
- Food Safety and Health Research Center, School of Public Health, Southern Medical University, Guangzhou, 510515, China; Department of Environmental and Occupational Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Moran Dong
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Jiaqi Wang
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Dengzhou Chen
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Wenjun Ma
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China
| | - Tao Liu
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, 510080, China; Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, 511430, China.
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Wang Q, Li B, Benmarhnia T, Hajat S, Ren M, Liu T, Knibbs LD, Zhang H, Bao J, Zhang Y, Zhao Q, Huang C. Independent and Combined Effects of Heatwaves and PM2.5 on Preterm Birth in Guangzhou, China: A Survival Analysis. ENVIRONMENTAL HEALTH PERSPECTIVES 2020; 128:17006. [PMID: 31909654 PMCID: PMC7015562 DOI: 10.1289/ehp5117] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 05/29/2023]
Abstract
BACKGROUND Both extreme heat and air pollution exposure during pregnancy have been associated with preterm birth; however, their combined effects are unclear. OBJECTIVES Our goal was to estimate the independent and joint effects of heatwaves and fine particulate matter [PM <2.5μm in aerodynamic diameter (PM2.5)], exposure during the final gestational week on preterm birth. METHODS Using birth registry data from Guangzhou, China, we included 215,059 singleton live births in the warm season (1 May-31 October) between January 2015 and July 2017. Daily meteorological variables from 5 monitoring stations and PM2.5 concentrations from 11 sites were used to estimate district-specific exposures. A series of cut off temperature thresholds and durations (2, 3, and 4 consecutive d) were used to define 15 different heatwaves. Cox proportional hazard models were used to estimate the effects of heatwaves and PM2.5 exposures during the final week on preterm birth, and departures from additive joint effects were assessed using the relative excess risk due to interaction (RERI). RESULTS Numbers of preterm births increased in association with heatwave exposures during the final gestational week. Depending on the heatwave definition used, hazard ratios (HRs) ranged from 1.10 (95% CI: 1.01, 1.20) to 1.92 (1.39, 2.64). Associations were stronger for more intense heatwaves. Combined effects of PM2.5 exposures and heatwaves appeared to be synergistic (RERIs>0) for less extreme heatwaves (i.e., shorter or with relatively low temperature thresholds) but were less than additive (RERIs<0) for more intense heatwaves. CONCLUSIONS Our research strengthens the evidence that exposure to heatwaves during the final gestational week can independently trigger preterm birth. Moderate heatwaves may also act synergistically with PM2.5 exposure to increase risk of preterm birth, which adds new evidence to the current understanding of combined effects of air pollution and meteorological variables on adverse birth outcomes. https://doi.org/10.1289/EHP5117.
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Affiliation(s)
- Qiong Wang
- School of Public Health, Sun Yat-sen University, Guangzhou, China
- Shanghai Typhoon Institute, China Meteorological Administration, Shanghai, China
- Shanghai Key Laboratory of Meteorology and Health, Shanghai Meteorological Service, Shanghai, China
| | - Bing Li
- Department of Healthcare, Guangdong Women and Children Hospital, Guangzhou, China
| | - Tarik Benmarhnia
- Department of Family Medicine and Public Health, University of California, San Diego, San Diego, USA
- Scripps Institution of Oceanography, University of California, San Diego, San Diego, California, USA
| | - Shakoor Hajat
- Department of Public Health, Environments and Society, London School of Hygiene & Tropical Medicine, London, UK
- Centre on Climate Change and Planetary Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Meng Ren
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Tao Liu
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Luke D. Knibbs
- School of Public Health, the University of Queensland, Brisbane, Australia
| | - Huanhuan Zhang
- School of Public Health, Sun Yat-sen University, Guangzhou, China
- School of Public Health, Zhengzhou University, Zhengzhou, China
| | - Junzhe Bao
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Yawei Zhang
- School of Public Health, Yale University, New Haven, USA
| | - Qingguo Zhao
- Epidemiological Research Office of Key Laboratory of Male Reproduction and Genetics (National Health and Family Planning Commission), Family Planning Research Institute of Guangdong Province/Family Planning Special Hospital of Guangdong Province, Guangzhou, China
| | - Cunrui Huang
- School of Public Health, Sun Yat-sen University, Guangzhou, China
- Shanghai Typhoon Institute, China Meteorological Administration, Shanghai, China
- Shanghai Key Laboratory of Meteorology and Health, Shanghai Meteorological Service, Shanghai, China
- School of Public Health, Zhengzhou University, Zhengzhou, China
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Ward A, Clark J, McLeod J, Woodul R, Moser H, Konrad C. The impact of heat exposure on reduced gestational age in pregnant women in North Carolina, 2011-2015. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2019; 63:1611-1620. [PMID: 31367892 DOI: 10.1007/s00484-019-01773-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 07/06/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Research on the impact of heat on pregnant women has focused largely on outcomes following extreme temperature events, such as particular heat waves or spells of very cold weather on pregnant women. Consistently, the literature has shown a statistically significant relationship between heat with shortened gestational age with studies concentrated largely in the western states of the USA or other nations. The association between heat and shortened gestational age has not been examined in the Southeastern US where maternal outcomes are some of the most challenging in the nation. Unlike previous studies that focus on the impacts of a single heat wave event, this study seeks to understand the impact of high heat over a 5-year period during the annual warm season (May-September). To achieve this goal, a case-crossover study design is employed to understand the impact of heat on preterm labor across regions in North Carolina (NC). Temperature thresholds for impact and the underlying relationships between preterm labor and heat are investigated using generalized additive models (GAM). Gridded temperature data (PRISM) is used to establish exposure classifications. The results reveal significant impacts to pregnant women exposed to heat with regional variations. The exposure variable with the most stable and significant result was minimum temperature, indicating high overnight temperatures have the most impact on preterm birth. The magnitude of this impact varies across regions from a 1% increase in risk to 6% increase in risk per two-degree increment above established minimum temperature thresholds.
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Affiliation(s)
- Ashley Ward
- Nicholas Institute of Environmental Policy Solution, Duke University, Box 90335, Durham, NC, 27708, USA.
| | - Jordan Clark
- Department of Geography, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jordan McLeod
- NOAA Southeast Regional Climate Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rachel Woodul
- Department of Geography, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Haley Moser
- Department of Geography, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Charles Konrad
- Department of Geography, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- NOAA Southeast Regional Climate Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Schumann B, Häggström Lundevaller E, Karlsson L. Weather extremes and perinatal mortality - Seasonal and ethnic differences in northern Sweden, 1800-1895. PLoS One 2019; 14:e0223538. [PMID: 31639133 PMCID: PMC6804957 DOI: 10.1371/journal.pone.0223538] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 09/23/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Many studies have shown the impact of heat and cold on total and age-specific mortality, but knowledge gaps remain regarding weather vulnerability of very young infants. This study assessed the association of temperature extremes with perinatal mortality (stillbirths and deaths in the first week of life), among two ethnic groups in pre-industrial northern Sweden. METHODS We used population data of indigenous Sami and non-Sami in selected parishes of northern Sweden, 1800-1895, and monthly temperature data. Multiple logistic regression models were conducted to estimate the association of cold (<10th percentile of temperature) and warmth (>90th percentile) in the month of birth with perinatal mortality, adjusted for cold and warmth in the month prior birth and period, stratified by season and ethnicity. RESULTS Perinatal mortality was slightly higher in Sami than in non-Sami (46 vs. 42 / 1000 live and stillbirths), but showed large variations across the region and over time. Both groups saw the highest perinatal mortality in autumn. For Sami, winter was a high-risk time as well, while for non-Sami, seasonality was less distinct. We found an association between exposure to cold and perinatal mortality among winter-born Sami [Odds ratio (OR) 1.91, 95% confidence interval (CI) 1.26-2.92, compared to moderate temperature], while there was little effect of cold or warmth during other seasons. Non-Sami, meanwhile, were affected in summer by warmth (OR 0.20, CI 0.05-0.81), and in autumn by cold (OR 0.39, CI 0.19-0.82). CONCLUSIONS In this pre-industrial, subarctic setting, the indigenous Sami's perinatal mortality was influenced by extreme cold in winter, while non-Sami seemed to benefit from high temperature in summer and low temperature in autumn. Climate vulnerability of these two ethnic groups sharing the same environment was shaped by their specific lifestyles and living conditions.
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Affiliation(s)
- Barbara Schumann
- Centre for Demographic and Ageing Research (CEDAR), Umeå University, Umeå, Sweden
- Department of Epidemiology and Global Health, Umeå University, Umeå, Sweden
| | | | - Lena Karlsson
- Centre for Demographic and Ageing Research (CEDAR), Umeå University, Umeå, Sweden
- Department of Sociology, Umeå University, Umeå, Sweden
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A Survey of Rural Residents' Perception and Response to Health Risks from Hot Weather in Ethnic Minority Areas in Southwest China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16122190. [PMID: 31234271 PMCID: PMC6616902 DOI: 10.3390/ijerph16122190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 05/31/2019] [Accepted: 06/19/2019] [Indexed: 12/05/2022]
Abstract
Ethnic minority areas in southwestern China are facing frequent high-temperature heatwaves. The health risk perceptions and responses of the local residents need to be investigated in order to formulate public policies to mitigate the impacts of climate change on health. In this study, a household survey was conducted in Pengshui Miao and Tujia Autonomous County of Chongqing from January to February 2019. A total of 624 local residents were sampled using the multi-stage sampling method. We used multivariate logistic regression models to explore the factors affecting risk perceptions and responses with regard to hot weather. The results showed that despite a relatively high level of risk perception, the study population had a very low level of willingness to see a doctor (24.4%), especially ethnic minority residents (17.5%). In particular, 80% of residents were aware of climate warming and 79% of residents were aware of the health risks of hot weather. Almost all survey participants reported a response to hot weather, with more than half of the participants stating that they would go somewhere cooler (58.5%) and drink more water (56.3%). Compared with the Han Chinese, ethnic minority participants had a higher perception of warm temperature (p <0.001) and associated health risks (p <0.001) but a lower perception of physical discomfort (p <0.001) and aggravated diseases (p = 0.001). The logistic models indicated that ethnic minority, residence time, outdoor working hours, and health status can significantly influence perceptions and subsequently significantly affect coping behaviors. In conclusion, our findings provide significant implications for the development of policies and health education and promotion programs for ethnic minorities in southwest China to aid them in maintaining good health during future hot weather events.
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Vulnerability to the Cardiovascular Effects of Ambient Heat in Six US Cities: Results from the Multi-Ethnic Study of Atherosclerosis (MESA). Epidemiology 2019; 29:756-764. [PMID: 30113342 DOI: 10.1097/ede.0000000000000910] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND With climate change, temperatures are increasing. Heat-associated health events disproportionately affect certain subpopulations. However, prior research has often lacked information on individual-level health and air conditioning and neighborhood stressors/protections. OBJECTIVES To assess whether (1) heat (2-day mean temperature above local 75th percentiles) is associated with increased heart rate and decreased blood pressure, controlling for age, time, season, daily ozone, and daily particulate matter (PM2.5) and (2) associations differ by antihypertensive medication use, renal function, fasting glucose, emotional support, air conditioning ownership and use, normalized difference vegetation index, neighborhood safety, and residence- specific oxides of nitrogen and PM2.5. METHODS Health and behavioral characteristics were obtained repeatedly on participants of the Multi-Ethnic Study of Atherosclerosis in six US sites (2000-2010). These were linked with airport temperature, air quality, and satellite- and survey-derived neighborhood characteristics. We used a fixed-effects design, regressing health outcomes on linear temperature splines with knots at the 75th percentiles, interaction terms for each characteristic, and adjustment for month of year, age, PM2.5, and ozone. RESULTS Overall, heat was not associated with heart rate. However, for a 2°C increase in heat, systolic blood pressure decreased by 1.1 mmHg (95% CI = -1.6, -0.6) and diastolic blood pressure by 0.3 mmHg (95% CI = -0.6, -0.1). Among nonusers of antihypertensive medications, heat-associated decreases in SBP were 2.1 mmHg greater among individuals with central air conditioning versus those without. Confidence intervals around the remaining modifiers were wide after multiple-comparisons corrections or sensitivity analyses. CONCLUSIONS Outdoor heat is associated with decreasing blood pressure, and cardiovascular vulnerability may vary primarily by ownership of central air conditioning.
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Li S, Wang J, Xu Z, Wang X, Xu G, Zhang J, Shen X, Tong S. Exploring associations of maternal exposure to ambient temperature with duration of gestation and birth weight: a prospective study. BMC Pregnancy Childbirth 2018; 18:513. [PMID: 30594173 PMCID: PMC6311008 DOI: 10.1186/s12884-018-2100-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 11/19/2018] [Indexed: 12/22/2022] Open
Abstract
Background Evidence suggests the possible impact of ambient high temperature on fetal growth and birth outcomes. However, little is known about the relative impact of exposure to heat and cold and the possible vulnerable window during pregnancy. Methods Data on a total of 237,585 pregnant women from January 1st, 2001 to December 31st, 2010 were acquired from the Queensland Health, Australia. Daily data on meteorological factors, including ambient temperature, relative humidity, barometric pressure, and air pollutants, such as PM10, SO2, NO2, and O3, were obtained from relevant government agencies. This study was to examine the associations of maternal exposure to ambient temperature (high and low temperatures, in early vs. late pregnancy) with the duration of gestation and birth weight. Results A J-shaped association between minimum temperature at conception and duration of gestation was observed after adjusting for seasonality and other confounders. Compared to women who were exposed to the minimum temperature of 15–20 °C in the first gestational week, exposure to the minimum temperature of > 20 °C significantly increased the duration of gestation by 0.029 weeks (95% CI: 0.008, 0.049). A cumulative effect was found when exposure across the first four weeks was examined. There was an inverted U-shaped relationship between minimum temperature at delivery and the duration of gestation. Compared to women exposed to 15–20 °C, exposure to minimum temperature of > 20 °C and ≤ 10 °C was associated with a shortened gestation by 0.030 weeks (95% CI: -0.052, − 0.008) and 0.018 weeks (95% CI: -0.057, − 0.004), respectively. By contrast, an inverse relationship between maximum temperature and birth weight was observed. Compared to exposure to the maximum temperature of > 30 °C in the last week of pregnancy, maternal exposure to 20–25 °C and < 20 °C significantly increased birth weight by 0.011 kg (95% CI: 0.008, 0.018) and 0.018 kg (95% CI: 0.010, 0.031), respectively. Similarly, a mild cumulative effect was observed when maximum temperature exposure across the four weeks before delivery was evaluated. Conclusions The finding emphasized the importance of keeping an optimal temperature range during pregnancy for reducing the risk of preterm birth and low birthweight. Electronic supplementary material The online version of this article (10.1186/s12884-018-2100-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shenghui Li
- School of Public Health, Shanghai Jiao Tong University, Shanghai, China. .,MOE - Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
| | - Jiajia Wang
- School of Public Health and Social Work, Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology, Brisbane, Australia
| | - Zhiwei Xu
- School of Public Health and Social Work, Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology, Brisbane, Australia
| | - Xiaoyu Wang
- School of Public Health and Social Work, Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology, Brisbane, Australia
| | - Gang Xu
- School of Public Health, Shanghai Jiao Tong University, Shanghai, China
| | - Jun Zhang
- School of Public Health, Shanghai Jiao Tong University, Shanghai, China.,MOE - Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaoming Shen
- School of Public Health, Shanghai Jiao Tong University, Shanghai, China.,MOE - Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shilu Tong
- School of Public Health and Social Work, Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology, Brisbane, Australia
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Liang Z, Wang P, Zhao Q, Wang BQ, Ma Y, Lin H, Xiao J, Zhou JY. Effect of the 2008 cold spell on preterm births in two subtropical cities of Guangdong Province, Southern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 642:307-313. [PMID: 29902628 DOI: 10.1016/j.scitotenv.2018.06.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/05/2018] [Accepted: 06/02/2018] [Indexed: 05/27/2023]
Abstract
BACKGROUND A few studies have reported that low temperatures were associated with an increased risk of preterm birth. However, the effect of extreme weather events, such as cold spell, on preterm birth has not been studied in China. OBJECTIVE This study was conducted to evaluate the impact of the 2008 cold spell on preterm birth in two subtropical cities of Guangdong Province. METHODS Data of daily preterm birth, air pollution and meteorological variables from 2006 to 2010 were collected in Dongguan and Shenzhen. A Poisson regression with a distributed lag nonlinear model was used to investigate the association between the 2008 cold spell and daily rate of preterm birth for each city. RESULTS During the 2008 cold spell, total vaginal preterm births were increased by 22.44% and 21.25% in Dongguan and Shenzhen, respectively. The effect of the cold spell on preterm births lasted for more than 1 week, the lag0-6 days cumulative relative risk (RR) is 1.32 (95% CI: 1.10-1.58) and 1.40 (95% CI: 1.18-1.68) in Dongguan and Shenzhen, respectively. The effects were found to be more pronounced for the pregnant women with 34-36 gestation weeks, maternal age < 35 years group. CONCLUSION This study demonstrates that cold spell could increase the risk of preterm births in Dongguan and Shenzhen, and the effect lasts for more than 1 week. Specific measures should be considered to protect the pregnant women, especially the vulnerable subgroups.
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Affiliation(s)
- Zhijiang Liang
- State Key Laboratory of Organ Failure Research, Ministry of Education, and Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Biostatistics, School of Public Health, Southern Medical University, Guangzhou 510515, China; Department of Public Health, Guangdong Women and Children Hospital, Guangzhou 511442, China
| | - Peng Wang
- State Key Laboratory of Organ Failure Research, Ministry of Education, and Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Biostatistics, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Qingguo Zhao
- Department of Epidemiology, Family Planning Research Institute of Guangdong Province, Guangzhou 510600, China
| | - Bei-Qi Wang
- State Key Laboratory of Organ Failure Research, Ministry of Education, and Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Biostatistics, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Yuanzhu Ma
- Department of Public Health, Guangdong Women and Children Hospital, Guangzhou 511442, China
| | - Hualiang Lin
- Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Jianpeng Xiao
- Department of Occupational Health and Occupational Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Ji-Yuan Zhou
- State Key Laboratory of Organ Failure Research, Ministry of Education, and Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Biostatistics, School of Public Health, Southern Medical University, Guangzhou 510515, China.
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Yu X, Feric Z, Cordero JF, Meeker JD, Alshawabkeh A. Potential influence of temperature and precipitation on preterm birth rate in Puerto Rico. Sci Rep 2018; 8:16106. [PMID: 30382121 PMCID: PMC6208375 DOI: 10.1038/s41598-018-34179-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 10/12/2018] [Indexed: 11/21/2022] Open
Abstract
The preterm birth (PTB) rate for singletons born in the tropical Caribbean island Puerto Rico increased from 11.3% in 1994, which was comparable to rates in the U.S., to as high as 18.3% in 2006 before decreasing to 15.5% in 2012. A few studies have reported that weather extremes are associated with higher risk of preterm birth, however, the effects of ambient temperature and precipitation has not been well examined in Puerto Rico. We compiled child birth data from the National Center for Health Statistics and weather data from the National Oceanic and Atmospheric Administration from 1994 to 2012. We explored the association between the weather factors and PTB rates with a distributed lag non-linear model (DLNM). We did not find direct association of lagged effect of temperature on birth outcome over monthly timescales. Both high intensity and frequency of precipitation and high frequency of storm and flood events are associated with increased risk of PTB rates. While the weather factors do not explain the marked increase and decrease in PTB rate, we emphasize the negative effects on PTB from weather extremes particularly precipitation in Puerto Rico.
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Affiliation(s)
- Xue Yu
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, USA
| | - Zlatan Feric
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, USA
| | - José F Cordero
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, GA, USA
| | - John D Meeker
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Akram Alshawabkeh
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, USA.
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Li S, Chen G, Jaakkola JJK, Williams G, Guo Y. Temporal change in the impacts of ambient temperature on preterm birth and stillbirth: Brisbane, 1994-2013. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 634:579-585. [PMID: 29635200 DOI: 10.1016/j.scitotenv.2018.03.385] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/19/2018] [Accepted: 03/31/2018] [Indexed: 05/24/2023]
Abstract
BACKGROUND Pregnant women are susceptible to ambient temperature which may associate with adverse birth outcomes. These associations might change over time due to adaptation. However, no evidence is available worldwide. OBJECTIVES To examine the effects of ambient temperature at three trimesters of pregnancy on preterm birth and stillbirth, and evaluate the effect changes during 1994-2013. METHODS Information on birth outcomes and meteorological parameters during 1994-2013 were obtained in Brisbane, Australia. Cox proportional hazards models were employed to evaluate the effects of mean temperature during each trimester of pregnancy on preterm birth and stillbirth. An interaction term between time and temperature was used to assess the potential changes in effects of temperature over time. RESULTS Both low and high temperatures at the 3rd trimester of pregnancy significantly increased the risk of preterm birth, with similar hazard ratios (HRs) [95% confidence intervals (CIs)] for low [1.21 (1.16, 1.27)] and high [1.21 (1.16, 1.26)] temperatures in comparison with thresholds. Increased risk of stillbirth was significantly associated with both low and high temperatures at the 2nd trimester of pregnancy, and lower HRs were observed for low temperature [1.23 (1.04, 1.45)] than high temperature [1.47 (1.24, 1.74)], in comparison with thresholds. The effects of low temperature became stronger, whereas the effects of high temperature became weaker from 1994 to 2013 for both preterm birth and stillbirth. CONCLUSIONS Both low and high ambient temperatures during pregnancy increase the risks of preterm birth and stillbirth. Pregnant women should have adapted to high temperature but not low temperature.
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Affiliation(s)
- Shanshan Li
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
| | - Gongbo Chen
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Jouni J K Jaakkola
- Center for Environmental and Respiratory Health Research and Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Gail Williams
- School of Public Health, The University of Queensland, Brisbane, Queensland, Australia
| | - Yuming Guo
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
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Zheng X, Zhang W, Lu C, Norbäck D, Deng Q. An epidemiological assessment of the effect of ambient temperature on the incidence of preterm births: Identifying windows of susceptibility during pregnancy. J Therm Biol 2018; 74:201-207. [PMID: 29801628 DOI: 10.1016/j.jtherbio.2018.04.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/31/2018] [Accepted: 04/03/2018] [Indexed: 01/07/2023]
Abstract
It is well known that exposure to thermal stress during pregnancy can lead to an increased incidence of premature births. However, there is little known regarding window(s) of susceptibility during the course of a pregnancy. We attempted to identify possible windows of susceptibility in a cohort study of 3604 children in Changsha with a hot-summer and cold winter climatic characteristics. We examined the association between PTB and ambient temperature during different timing windows of pregnancy: conception month, three trimesters, birth month and entire pregnancy. We found a U-shaped relation between the prevalence of PTB and mean ambient temperature during pregnancy. Both high and low temperatures were associated with PTB risk, adjusted OR (95% CI) respectively 2.57 (1.98-3.33) and 2.39 (1.93-2.95) for 0.5 °C increase in high temperature range (>18.2°C) and 0.5°C decrease in low temperature range (< 18.2°C). Specifically, PTB was significantly associated with ambient temperature and extreme heat/cold days during conception month and the third trimester. Sensitivity analysis indicated that female fetus were more susceptible to the risk of ambient temperature. Our study indicates that the risk of preterm birth due to high or low temperature may exist early during the conception month.
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Affiliation(s)
- Xiangrong Zheng
- Department of Pediatrics, XiangYa Hospital, Central South University, Changsha, China
| | - Weishe Zhang
- Department of Obstetrics, XiangYa Hospital, Central South University, Changsha, China
| | - Chan Lu
- School of Energy Science and Engineering, Central South University, Changsha, China
| | - Dan Norbäck
- School of Energy Science and Engineering, Central South University, Changsha, China; Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Qihong Deng
- School of Energy Science and Engineering, Central South University, Changsha, China; XiangYa School of Public Health, Central South University, Changsha, China; Center for Environment and Water Resources, Central South University, Changsha, China.
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Chen G, Guo Y, Abramson MJ, Williams G, Li S. Exposure to low concentrations of air pollutants and adverse birth outcomes in Brisbane, Australia, 2003-2013. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:721-726. [PMID: 29223898 DOI: 10.1016/j.scitotenv.2017.12.050] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND It's unclear whether exposures to low-level air pollution have adverse effects on birth outcomes, and which trimester-specific pregnant exposure is sensitive. OBJECTIVES To investigate the effects of maternal exposure during each trimester and the whole pregnancy to particles with aerodynamic diameter<2.5μm (PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3) on preterm birth (PTB) and low birth weight (LBW). METHODS Daily data on birth records, air quality, and weather conditions were collected in Brisbane, Australia during 2003-2013. Mean concentrations of air pollutants were calculated for each trimester of pregnancy. Cox proportional hazards models were used to examine the associations between air pollution and birth outcomes. Multi-pollutant models and stratified analyses by ambient temperature were performed. RESULTS Exposures to PM2.5, SO2, NO2, and O3 during the whole pregnancy were associated with increased risk of PTB [IQR HRs (hazard ratios with an interquartile range increase in air pollutants) and 95% confidence intervals (CIs): 1.05 (1.02, 1.08), 1.12 (1.09, 1.16), 1.07 (1.01, 1.13), and 1.13 (1.10, 1.16), respectively] and LBW [IQR HRs and 95% CIs: 1.06 (1.02, 1.10), 1.12 (1.08, 1.16), 1.11 (1.03, 1.18), and 1.13 (1.09, 1.17), respectively]. Highest HRs were observed during trimester 3, and lowest in trimester 1. For each air pollutant, stronger effects on PTB and LBW were present for exposure to low and moderate temperatures than exposure to high ambient temperature. CONCLUSIONS Exposures to low-level air pollutants are related to adverse birth outcomes. More effective policies for air quality control could contribute to improving neonatal health.
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Affiliation(s)
- Gongbo Chen
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Yuming Guo
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Michael J Abramson
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Gail Williams
- School of Public Health, The University of Queensland, Brisbane, Queensland, Australia
| | - Shanshan Li
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia; School of Public Health, The University of Queensland, Brisbane, Queensland, Australia.
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Auger N, Fraser WD, Smargiassi A, Bilodeau-Bertrand M, Kosatsky T. Elevated outdoor temperatures and risk of stillbirth. Int J Epidemiol 2018; 46:200-208. [PMID: 27160765 DOI: 10.1093/ije/dyw077] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/16/2016] [Indexed: 12/15/2022] Open
Abstract
Background The causes of stillbirth are poorly understood, including whether elevated outdoor temperatures increase risk. We assessed the relationship between elevated ambient temperatures and risk of stillbirth by gestational age and cause of death during warm months in a temperate region. Methods We performed a case-crossover study of 5047 stillbirths in continental Quebec, Canada, between the months of April through September from 1981 to 2011. Using data on maximum daily temperatures adjusted for relative humidity, we estimated associations with stillbirth, comparing temperatures before fetal death with temperatures on adjacent days. The main outcomes were stillbirth according to age of gestation (term, preterm), and cause of death (undetermined, maternal, placenta/cord/membranes, birth asphyxia, congenital anomaly, other). Results Elevated outdoor temperatures the week before the death were more strongly associated with risk of term than preterm stillbirth. Odds of term stillbirth for temperature 28 °C the day before death were 1.16 times greater relative to 20 °C (95% confidence interval, CI 1.02-1.33). Elevated outdoor temperature was associated with stillbirth due to undetermined and maternal causes, but not other causes. Compared with 20 °C, the odds of stillbirth at 28 °C were 1.19 times greater for undetermined causes (95% CI 1.02-1.40) and 1.46 times greater for maternal complications (95% CI 1.03-2.07). Conclusions Elevated outdoor temperatures may be a risk factor for term stillbirth, including stillbirth due to undetermined causes or maternal complications.
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Affiliation(s)
- Nathalie Auger
- Institut national de santé publique du Québec and University of Montreal Hospital Research Centre, Montreal, QC, Canada
| | - William D Fraser
- Centre de recherche du CHUS and Department of Obstetrics and Gynecology, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Audrey Smargiassi
- Department of Occupational and Environmental Health, University of Montreal, Montreal, QC, Canada and
| | - Marianne Bilodeau-Bertrand
- Institut national de santé publique du Québec and University of Montreal Hospital Research Centre, Montreal, QC, Canada
| | - Tom Kosatsky
- National Collaborating Centre for Environmental Health, British Columbia Centre for Disease Control, Vancouver, BC, Canada
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Abstract
Supplemental Digital Content is available in the text. Background: Daily changes in aeroallergens during pregnancy could trigger early labor, but few investigations have evaluated this issue. This study aimed to investigate the association between exposure to aeroallergens during the week preceding birth and the risk of early delivery among preterm and term pregnancies. Methods: We identified data on 225,234 singleton births that occurred in six large cities in the province of Ontario, Canada, from 2004 to 2011 (April to October) from a birth registry. We obtained daily counts of pollen grains and fungal spores from fixed-site monitoring stations in each city and assigned them to pregnancy period of each birth. Associations between exposure to aeroallergens in the preceding week and risk of delivery among preterm (<37 gestational weeks), early-term (37–38 weeks), and full-term (≥39 weeks) pregnancies were evaluated with Cox regression models, adjusting for maternal characteristics, meteorologic parameters, and air pollution concentrations, and pooled across the six cities. Results: The risk of delivery increased by 3% per interquartile range width (IQRw = 22.1 grains/m3) increase in weed pollen the day before birth among early-term (hazard ratio [HR] = 1.03; 95% confidence interval [CI]: 1.01, 1.05) and full-term pregnancies (HR = 1.03; 95% CI: 1.01, 1.04). Exposure to fungal spores cumulated over 0 to 2 lagged days was associated with increased risk of delivery among full-term pregnancies only (HR = 1.07; 95% CI: 1.01, 1.12). We observed no associations among preterm deliveries. Conclusions: Increasing concentrations of ambient weed pollen and fungal spores may be associated with earlier delivery among term births.
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Cil G, Cameron TA. Potential Climate Change Health Risks from Increases in Heat Waves: Abnormal Birth Outcomes and Adverse Maternal Health Conditions. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2017; 37:2066-2079. [PMID: 28230268 DOI: 10.1111/risa.12767] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 12/08/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
We investigate the risks presented by heat waves for adverse health conditions for babies and expectant mothers when these mothers have been exposed to heat waves during gestation or during the period just prior to conception. Rather than just birth weight and gestational age, we focus on less common metrics such as abnormal conditions in the newborn (fetal distress, reliance on a ventilator, and meconium aspiration) and adverse health conditions in the mother (pregnancy-related hypertension, uterine bleeding during pregnancy, eclampsia, and incompetent cervix). We use monthly panel data for over 3,000 U.S. counties, constructed from the confidential version of the U.S. Natality Files for 1989-2008. Our models control for sociodemographic factors and include county, month, and state-by-year fixed effects to control for unobserved spatial and timewise heterogeneity in the data. Even within the United States, where there is widespread access to air conditioning, heat waves increase the fraction of babies with abnormal conditions related to maternal stress, as well as the fraction of mothers who experience pregnancy-related adverse health conditions. The scope for these risks in developing countries is likely to be even greater.
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Affiliation(s)
- Gulcan Cil
- Department of Economics, University of Oregon, Eugene, OR, USA
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Heat Exposure and Maternal Health in the Face of Climate Change. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14080853. [PMID: 28758917 PMCID: PMC5580557 DOI: 10.3390/ijerph14080853] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/18/2017] [Accepted: 07/23/2017] [Indexed: 12/17/2022]
Abstract
Climate change will increasingly affect the health of vulnerable populations, including maternal and fetal health. This systematic review aims to identify recent literature that investigates increasing heat and extreme temperatures on pregnancy outcomes globally. We identify common research findings in order to create a comprehensive understanding of how immediate effects will be sustained in the next generation. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guide, we systematically reviewed articles from PubMed and Cochrane Reviews. We included articles that identify climate change-related exposures and adverse health effects for pregnant women. There is evidence that temperature extremes adversely impact birth outcomes, including, but not limited to: changes in length of gestation, birth weight, stillbirth, and neonatal stress in unusually hot temperature exposures. The studies included in this review indicate that not only is there a need for further research on the ways that climate change, and heat in particular, may affect maternal health and neonatal outcomes, but that uniform standards for assessing the effects of heat on maternal fetal health also need to be established.
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Muresan D, Staicu A, Zaharie G, Marginean C, Rotar IC. The influence of seasonality and weather changes on premature birth incidence. ACTA ACUST UNITED AC 2017; 90:273-278. [PMID: 28781523 PMCID: PMC5536206 DOI: 10.15386/cjmed-744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 11/28/2016] [Indexed: 12/18/2022]
Abstract
Background Although the effects of meteorological factors on the general population health are widely documented, little is known about their influence on human pregnancy and birth. The present study aims at analyzing the influence of the atmospheric conditions on premature births. Method One hundred and eight nine cases of premature births were included in the study, with a gestational age between 24 to 37 weeks of amenorrhea. Cases with antepartum fetal death and those with uncertain gestational age have been excluded. Daily weather data were obtained using http://www.wunderground.com site. A Pearson’s product-moment correlation was run to assess the relationship between weekly preterm birth incidence and the total number of premature births and the mean maximum and minimum temperature (Tmax, Tmin), maximum and minimum average humidity (Umax, Umin), maximum and minimum atmospheric pressure mean (P max, P min), average wind speed and average quantity precipitations, calculated for one calendar week. Results Approximately 7.7% of all births during the study period occurred before 37 weeks of gestation, the main reason for hospitalization being premature rupture of membranes (45%). The analysis revealed a moderate positive correlation between weekly preterm birth incidence and the average temperature (r=0.306, n=52, p=0.027) and a moderate positive correlation between weekly preterm birth incidence and temperature variation (r=0.307, n=52, p=0.007). Our study found no significant statistic correlation between the humidity variation, pressure variation, and wind speed. Conclusions The incidence of premature births can be influenced by variations of specific weather factors, especially during the weeks characterized by large fluctuations in temperature. The results obtained might inspire the construction of multicenter studies to investigate more thoroughly the adverse effects of some meteorological factors that can influence the outcomes of human pregnancy.
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Affiliation(s)
- Daniel Muresan
- 1 Obstetrics and Gynecology Department, Iuliu Hatieganu University of Medicine and Pharmacy Cluj-Napoca, Romania
| | - Adelina Staicu
- 1 Obstetrics and Gynecology Department, Iuliu Hatieganu University of Medicine and Pharmacy Cluj-Napoca, Romania
| | - Gabriela Zaharie
- Neonatology Department, Iuliu Hatieganu University of Medicine and Pharmacy Cluj-Napoca, Romania
| | - Claudiu Marginean
- Department of Obstetrics and Gynecology I, University of Medicine and Pharmacy of Targu Mures, Romania
| | - Ioana Cristina Rotar
- 1 Obstetrics and Gynecology Department, Iuliu Hatieganu University of Medicine and Pharmacy Cluj-Napoca, Romania
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Zhang Y, Yu C, Wang L. Temperature exposure during pregnancy and birth outcomes: An updated systematic review of epidemiological evidence. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 225:700-712. [PMID: 28284544 DOI: 10.1016/j.envpol.2017.02.066] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/24/2017] [Accepted: 02/28/2017] [Indexed: 05/02/2023]
Abstract
Seasonal patterns of birth outcomes have been observed worldwide, and there was increasing evidence that ambient temperature played as a trigger of adverse birth outcomes, such as preterm birth (PTB), low birth weight (LBW), and stillbirth. To systematically review updated epidemiological evidence about the relationship between temperature exposure during pregnancy and PTB, LBW, and stillbirth, we searched for related studies published in English from electronic databases and references of identified papers. We only included original articles that directly reported the effects of prenatal temperature exposure on birth outcomes. The characteristics and main findings of included studies were examined. A total of 36 epidemiological studies were finally included in this review. Most of these studies focused on PTB and LBW, while less attention has been paid to stillbirth that was relatively rare in the occurrence. Several designs including ecological (e.g., descriptive and time-series) and retrospective cohort studies (e.g., case-crossover and time-to-event) were applied to assess temperature effects on birth outcomes. Temperature metrics and exposure windows varied greatly in these investigations. Exposure to high temperature was generally found to be associated with PTB, LBW, and stillbirth, while several studies also reported the adverse impact of low temperature on birth outcomes of PTB and LBW. Despite no conclusive causality demonstrated, the current evidence for adverse effect on birth outcomes was stronger for heat than for cold. In summary, the evidence linking birth outcomes with ambient temperature was still very limited. Consequently, more related studies are needed worldwide and should be conducted in diversified climate zones, so as to further ascertain the association between temperature and birth outcomes. Future studies should focus on more sophisticated study designs, more accurate estimation of temperature exposure during pregnancy, and more efficient methods to find out the exposure windows, as well as cold-related effects on birth outcomes.
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Affiliation(s)
- Yunquan Zhang
- Department of Epidemiology and Biostatistics, School of Health Sciences, Wuhan University, 185 Donghu Road, Wuchang District, Wuhan 430071, China
| | - Chuanhua Yu
- Department of Epidemiology and Biostatistics, School of Health Sciences, Wuhan University, 185 Donghu Road, Wuchang District, Wuhan 430071, China; Global Health Institute, Wuhan University, 8 Donghunan Road, Wuchang District, Wuhan 430072, China.
| | - Lu Wang
- Department of Epidemiology and Biostatistics, School of Health Sciences, Wuhan University, 185 Donghu Road, Wuchang District, Wuhan 430071, China
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Basu R, Chen H, Li DK, Avalos LA. The impact of maternal factors on the association between temperature and preterm delivery. ENVIRONMENTAL RESEARCH 2017; 154:109-114. [PMID: 28056406 PMCID: PMC5459758 DOI: 10.1016/j.envres.2016.12.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/19/2016] [Indexed: 05/11/2023]
Abstract
BACKGROUND Few studies have examined maternal modifiers of temperature and adverse birth outcomes because of lack of data. We assessed the relationship between apparent temperature, preterm delivery (PTD) and maternal demographics, medical and mental health conditions, and behaviors. METHODS A time-stratified case-crossover analysis was conducted using 14,466 women who had a PTD (20 to less than 37 gestational weeks) from 1995 to 2009 using medical records from a large health maintenance organization in Northern California. Effect modifiers considered by stratification included several maternal factors: age, race/ethnicity, depression, hypertension, diabetes, smoking, alcohol use, pre-pregnancy body mass index, and Medicaid status. Apparent temperature data for women who had a monitor located within 20km of their residential zip codes were included. All analyses were stratified by warm (May 1 through October 31) and cold (November 1 through April 30) seasons. RESULTS For every 10°F (5.6°C) increase in average cumulative weekly apparent temperature (lag06), a greater risk was observed for births occurring during the warm season (11.63%; 95% CI: 4.08, 19.72%) compared to the cold season (6.18%; -2.96, 16.18%), especially for mothers who were younger, Black, Hispanic, underweight, smoked or consumed alcohol during pregnancy, or had pre-existing /gestational hypertension, diabetes, or pre-eclampsia. CONCLUSIONS Our findings suggest that warmer apparent temperatures exacerbate the risk of PTD, particularly for subgroups of more vulnerable women.
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Affiliation(s)
- Rupa Basu
- California Office of Environmental Health Hazard Assessment, Air and Climate Epidemiology Section, Oakland, CA, United States.
| | - Hong Chen
- Kaiser Permanente Northern California, Division of Research, Oakland, CA, United States
| | - De-Kun Li
- Kaiser Permanente Northern California, Division of Research, Oakland, CA, United States
| | - Lyndsay A Avalos
- Kaiser Permanente Northern California, Division of Research, Oakland, CA, United States
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