Associations between high temperatures in pregnancy and risk of preterm birth, low birth weight, and stillbirths: systematic review and meta-analysis

'Too much, too little' - heat wave impact during pregnancy and the need for adaptation measures

The balls are rolling for climate change, with increasing vulnerability to women and children related to climate extreme events. Recent evidence has shown that acute exposure to heat wave during pregnancy can be associated with adverse health outcomes in childhood, with the risk being significantly higher among socially disadvantaged population, despite their lack of contribution to global carbon dioxide emissions and the rising global ambient temperature. This unequal impact requires utmost attention to develop tools, establish interdisciplinary teams, and to implement evidence-based interventions for the betterment of women and children in climate-vulnerable populations.

Amazon's climate crossroads: analyzing air pollution and health impacts under machine learning-based temperature increase scenarios in Northern Mato Grosso, Brazil

Air pollution has long been a public health concern in South America, now increasingly linked to climate change. In Brazil, this issue is particularly acute in smaller cities with limited monitoring infrastructure. Sinop, located in the Amazon biome of Mato Grosso, exemplifies the intersection of agricultural expansion and environmental vulnerability. This study presents a comprehensive assessment of meteorological conditions, air pollutant levels, and related health impacts in Sinop, focusing on PM2.5, PM10, and ground-level ozone (O3). Using 2022 data, we applied Health Impact Assessment (HIA) via the WHO's AirQ + tool and simulated temperature rise scenarios through a machine learning model. ur findings indicate that O3 levels are highly sensitive to meteorological variation, while PM2.5 and PM10 concentrations are projected to increase by up to 50% and 70%, respectively, under extreme warming scenarios. These changes correspond to an estimated increase in non-external mortality of over 90% for PM2.5 and more than 1000% for PM10. Seasonal simulations revealed that the dry season, marked by intense biomass burning, significantly exacerbates pollutant concentrations. These results underscore the growing burden of air pollution on public health in rapidly urbanizing regions. They also highlight the urgent need for enhanced air quality monitoring and climate-adaptive public health strategies in vulnerable areas such as the southern Amazon.

Exposure to Extreme Heat Increases Preterm Birth Risk: Hypothetical Pathophysiological Mechanisms

Preterm birth (PTB), delivery before 37 weeks of gestation, is the leading cause of neonatal mortality globally, accounting for nearly half of all neonatal deaths. While numerous established risk factors for PTB have been identified, ongoing research continues to elucidate additional contributing factors. Epidemiological studies increasingly demonstrate that elevated ambient temperature is an environmental risk factor for PTB, with odds increasing 16% during heat waves and 5% per 1°C temperature rise. This is particularly concerning given escalating global warming trends. While maternal heat susceptibility during pregnancy may be linked to compromised thermoregulation from gestational adaptations, the exact pathophysiological mechanisms leading to heat-associated PTB remain unclear, hindering therapeutic development. This review proposes multitudes potential pathophysiologic mechanisms leading to PTB that can be induced by heat. They include but are not limited to metabolic derangement, mitochondria dysfunction, inflammation, endothelial dysfunction, oxidative stress, and change in cell fate. These mechanisms are derived from integrated knowledge of pregnancy physiology, parturition processes, and temperature effects on physiological pathways. We also outline future experimental approaches to test these hypotheses.

Heat in the transport sector: measured heat exposure and interventions to address heat-related health impacts in the minibus taxi industry in South Africa

High temperatures, heat and heatwaves are being experienced more frequently and with greater intensity in many parts of the world, including South Africa, and record-breaking maximum temperatures are becoming more common. Exposure to heat has adverse impacts on human health and wellbeing. The transport sector and its users are vulnerable to heat both inside vehicles as well as in places where people wait for public transport. We sought to assess the temperatures experienced in minibus taxis, a common mode of transport in South Africa and in minibus taxi ranks as well as the heat-related perceptions of minibus taxi drivers working in the Chesterville Taxi Association in Durban. We also observed heat-related elements in minibus taxi ranks. Data from temperature loggers showed that temperatures inside minibus taxis reached up to 39 °C and were between 3-4 °C warmer than outdoors. For around 11 h every day, temperatures inside minibus taxis were warmer than 27 °C - the temperature that is linked to heat-health symptoms. Taxi drivers (N = 16) all agreed they feel hot in the minibus taxi and more than 90% said they drink water to try to cool down. Taxi ranks were lacking in supply of drinking water and shade for minibus taxis and seating. With the projected increase in temperatures caused by climate change, it is imperative to co-develop mitigation and adaptation strategies to minimise heat-related human health impacts in minibus taxis and taxi ranks especially in low- and middle-income countries.

Factors related to successful medication management with mifepristone and misoprostol in missed miscarriage: a retrospective case-control study

BACKGROUND

Treatment with mifepristone in combination with misoprostol may be a safe and less expensive option compared with surgical management in missed miscarriage, but the efficacy of medication management varies in clinical practice. This study aims to identify the risk factors related to successful medical management using mifepristone and misoprostol for missed miscarriage.

METHODS

We carried out a retrospective case-control study in the First Affiliated Hospital with Nanjing Medical University from January 1, 2023 to December 31, 2023. Patients were recruited into this study if they were aged 16 years and older, diagnosed with a missed miscarriage by pelvic ultrasound scan in the first 13 weeks of pregnancy (by last menstrual period), and chose to have medication management. Women who failed to spontaneously pass the gestational sac within 24 h of the oral misoprostol dose were included in the case group, while women who had complete gestational sac expulsion within 24 h of the oral misoprostol dose were defined as controls. The baseline characteristics of the patients were collected in the electronic medical record system and the meteorological data were obtained from the Nanjing Meteorological Observation Centre. Logistic regression analysis was used to identify the risk factors which affected medication management efficacy.

RESULTS

A total of 163 patients met inclusion criteria, including 60 patients in the case group and 103 patients in the control group. Our results showed that the history of gravidity, history of parity, history of miscarriage, history of caesarean section, prior uterine surgery, and the use of supplemental vaginal misoprostol could be potential risk factors, while the remaining variables showed no significant differences between the two groups. The univariable logistic regression model demonstrated that the risk of unsuccessful medication management was increased 3.67-fold in patients who had been pregnant more than 3 times (95% CI: 1.66, 8.08; p = 0.001); increased 2.29-fold in parous women (95% CI: 1.13, 4.62; p = 0.021); and increased 2.09-fold in patients who had previous miscarriages (95% CI: 1.10, 4.00; p = 0.026). Additionally, prior uterine surgery was related to the outcomes of medication management (OR: 2.94; 95% CI: 1.46, 5.93; p = 0.003), especially caesarean section (OR: 2.09; 95% CI: 1.13, 4.62; p = 0.021). Interestingly, the repeated vaginal administration of misoprostol was not associated with an increased success rate (OR: 3.65; 95% CI: 1.76, 7.56; p = 0.001). Moreover, we evaluated the effect of meteorological factors on which the exposure of 4 days average visibility emerged as a statistically significant risk factor (OR: 1.13, 95% CI: 1.01, 1.27; p = 0.036). Multivariable logistic regression model showed that the history of parity, prior uterine surgery, use of supplemental vaginal misoprostol and 4 days average visibility were still independently associated with the outcomes of medication management, while the gestational age by ultrasound was no longer related.

CONCLUSIONS

The missed miscarriage patients who are parous or have uterine surgery history may suffer from a higher risk of unsuccessful medication management. The exposure to reduced visibility had a significant influence on the efficacy of mifepristone and misoprostol, while the supplementary administration of vaginal misoprostol could not increase the chance of successful miscarriage management.

Prevention and Management of Growth Failure During the First 6 Months of Life: Recommendations by the Joint Committee of the Pediatric and Adolescent Nutrition Society and the IAP Infant and Young Child Feeding Chapter

OBJECTIVE

To develop evidence-based guidelines for the prevention, identification, and management of growth failure in infants under 6 months (U6M), ensuring early detection and intervention to improve health outcomes.

JUSTIFICATION

Growth failure in the first 6 months of life significantly increases the risk of acute malnutrition and stunting in later childhood. Unlike older children, management in this age group prioritizes establishing exclusive breastfeeding and addressing feeding challenges. There are no standardized guidelines for identifying and managing growth failure in this vulnerable population.

PROCESS

A national consultative committee of experts was convened to formulate these guidelines. The committee conducted extensive discussions, dividing key areas among six working groups. The process included four virtual and one in-person meeting between August and October 2024. A draft guideline was developed, reviewed, and approved by all committee members.

RECOMMENDATIONS

Early growth failure is a significant public health concern. Timely identification of at-risk infants through mother-infant dyad assessments during routine health visits is essential. Weight-for-age is the most reliable anthropometric indicator for recognizing at-risk infants U6M. The term "infant at risk of poor growth and development" is recommended to identify at-risk infants needing intensified support. Community-based interventions should support at-risk infants without medical complications, while those with complications need facility-based care with skilled lactation support. Severely wasted infants require close monitoring for hypothermia, hypoglycemia, and sepsis. Establishing exclusive breastfeeding should be prioritized in all cases, and when not feasible, F-100D (Catch-up D) should be used to ensure safe nutritional rehabilitation while minimizing renal solute load.

Independent and joint effects of air quality index and the average ambient temperature on in vitro fertilization pregnancy outcomes in Zhengzhou, China

OBJECTIVES

This study aimed to estimate the independent and joint effects of the air quality index (AQI) and the average temperature on IVF pregnancy outcomes.

METHODS

We retrospectively analyzed 15,326 first fresh cycles garnered from January 2015 to December 2021 at the First Affiliated Hospital of Zhengzhou University. Daily average levels of AQI and air temperature were obtained from fixed monitoring stations near patients' residences. They were divided into six different exposure periods according to the clinical timeline of IVF treatment. Logistic regression analysis and the interaction calculation table were used to assess independent and joint effects.

RESULTS

The effects of AQI and the average temperature on clinical pregnancy were not statistically significant across age groups and window periods. However, AQI and the average temperature significantly impacted live births. We only found a significant interaction effect of AQI and the average temperature on live births, more vital in periods after embryo transfer (ET) compared to the various pre-ET windows. The independent and joint associations were more pronounced in those < 35 years of age.

CONCLUSIONS

AQI and the average temperature did not affect clinical pregnancy but were negatively correlated with the probability of live birth. There was an interaction effect between the AQI and average temperature on live birth, significantly reducing the odds of live birth, especially after ET. These correlations were more pronounced in the < 35-year-old population than ≥ 35-year-old.

Risk of Adverse Birth Outcomes and Birth Defects Among Women Living With HIV on Antiretroviral Therapy and HIV-Negative Women in Uganda, 2015-2021

INTRODUCTION

We assessed the risk of adverse pregnancy and birth outcomes and birth defects among women living with HIV (WLHIV) on antiretroviral therapy (ART) and HIV-negative women.

METHODS

We analyzed data on live births, stillbirths, and spontaneous abortions during 2015-2021 from a hospital-based birth defects surveillance system in Kampala, Uganda. ART regimens were recorded from hospital records and maternal self-reports. Using a log-binomial regression model, we compared the prevalence of 16 major external birth defects and other adverse birth outcomes among WLHIV on ART and HIV-negative women.

RESULTS

A total of 203,092 births were included from 196,373 women of whom 15,020 (7.6%) were WLHIV on ART. During pregnancy, 15,566 infants were primarily exposed to non-nucleoside reverse transcriptase inhibitor-based ART (n = 13,614; 87.5%). After adjusting for maternal age, parity, and number of antenatal care visits, WLHIV on non-nucleoside reverse transcriptase inhibitor were more likely than HIV-negative women to deliver preterm (adjusted prevalence ratio [aPR] = 1.27, 95% confidence interval: 1.21 to 1.32), post-term (aPR = 1.23, 95% CI: 1.16 to 1.32), or small for gestational age infants (aPR = 1.35, 95% CI: 1.30 to 1.40). Spina bifida was more prevalent among infants born to WLHIV on ART periconceptionally compared with HIV-negative women (aPR = 2.45, 95% CI: 1.27 to 4.33). The prevalence of the other selected birth defects was similar between infants from WLHIV on ART and HIV-negative women.

CONCLUSIONS

In Uganda, WLHIV on ART were more likely than HIV-negative women to experience selected adverse birth outcomes. Further surveillance of maternal ART exposure, including by drug class and ART regimen, is needed to monitor and prevent adverse birth outcomes in WLHIV.

Impact of early life exposure to heat and cold on linguistic development in two-year-old children: findings from the ELFE cohort study

BACKGROUND

A number of negative developmental outcomes in response to extreme temperature have been documented. Yet, to our knowledge, environmental research has left the question of the effect of temperature on human neurodevelopment largely unexplored. Here, we aimed to investigate the effect of ambient temperature on linguistic development at the age of 2 years-old.

METHODS

We used data from the prospective national French birth cohort ELFE (N = 12,163) and highly-resolved exposure models with daily temporal resolution and 200 m to 1 km spatial resolution. We investigated the effect of weekly averages of overall, daytime and night-time temperature in the prenatal (first 30 weeks of gestation) and postnatal (91 weeks after birth) period on vocabulary production scores from the MacArthur-Bates Communicative Development Inventories (MB-CDI) at 2 years-old. Exposure-response and lag-response relationships were modeled with confounder-adjusted distributed lag non-linear models.

RESULTS

Scores at the MB-CDI decreased by 3.2% (relative risk (RR) 0.968, 95% confidence interval (CI): 0.939-0.998) following exposure to severe night-time heat of 15.6 °C (95th percentile) vs. 8.3 °C (median) throughout gestational weeks 14 to 19. In the postnatal period, scores at the MB-CDI decreased by 14.8% (RR 0.852; 95% CI: [0.756-0.96]) for severe overall heat of 21.9 °C (95th percentile) vs. 11.5 °C (median) throughout weeks 1 to 28. Consistent results were found for daytime and night-time heat. We observed positive effects of overall and night-time heat in the first few weeks of pregnancy. Night-time cold in the pre-natal period also resulted in improved scores at the MB-CDI. Adjusting our models for air pollutants (PM2.5, PM10 and NO2) tended to confirm these observations. Finally, there were no significant differences in temperature effects between boys and girls.

CONCLUSION

In this large cohort study, we showed a negative impact of hot temperatures during pregnancy and after birth on language acquisition. Positive associations observed in the first few weeks of pregnancy are likely the results of methodological artifacts. Positive associations with night-time cold during the prenatal period are likely truly protective, as colder temperatures may encourage staying indoors at a comfortable temperature. Policymakers should consider neurodevelopment impairments as a deleterious effect of climate change.

Exposure to low concentrations of PM2.5 and its constituents with preterm birth in Shenzhen, China: a retrospective cohort study

BACKGROUND

Due to the Air Pollution Prevention and Control Measures issued by the Chinese government, air quality has significantly improved, particularly with respect to PM2.5. However, studies on the relationship between low concentrations of PM2.5 and preterm birth (PTB) remain limited in China.

OBJECTIVE

To examine the associations between low concentrations of PM2.5 and its constituents and PTB.

METHODS

This retrospective cohort study was conducted from July 2021 to April 2023 in Shenzhen, China. Data on questionnaires and pregnancy outcomes were collected for each participant. Using the Tracking Air Pollution in China (TAP) dataset, we assessed the concentrations of PM2.5 and its chemical constituents, including sulfate (SO42-), nitrate (NO3-), organic matter (OM), black carbon (BC), and ammonium (NH4+). We applied a generalized additive model (GAM) to evaluate the relationship. The relationship between exposure to PM2.5 and its constituents and PTB was further examined using a method that combined dummy variable settings with trend tests. Stratified analysis was conducted to explore the potential factors.

RESULTS

Among 17,240 live-born infants, the rate of PTB was 6.0%, and the average exposure concentration of PM2.5 was 20.24 μg/m3. There were positive associations between PM2.5 and its constituents and PTB. With each interquartile range (IQR) increase in PM2.5 during the third trimester, the risk of PTB increased by 2.23 times. The exposure effects of sulfate (SO42-) and organic matter (OM) were comparable to the total PM2.5. The third trimester might be the critical susceptibility window. The risk was higher among women who conceived in the cold season and were exposed to higher temperatures during pregnancy.

CONCLUSION

Even at low levels, PM2.5 can still increase the risk of PTB, with varying health effects attributed to different constituents. This underscores the importance of further strengthening environmental management and characterizing the contributions of PM2.5 sources.

Maternal Health Risk Detection: Advancing Midwifery with Artificial Intelligence

Background/Objectives: Maternal health risks remain one of the critical challenges in the world, contributing much to maternal and infant morbidity and mortality, especially in the most vulnerable populations. In the modern era, with the recent progress in the area of artificial intelligence and machine learning, much promise has emerged with regard to achieving the goal of early risk detection and its management. This research is set out to relate high-risk, low-risk, and mid-risk maternal health using machine learning algorithms based on physiological data. Materials and Methods: The applied dataset contains 1014 instances (i.e., cases) with seven attributes (i.e., variables), namely, Age, SystolicBP, DiastolicBP, BS, BodyTemp, HeartRate, and RiskLevel. The preprocessed dataset used was then trained and tested with six classifiers using 10-fold cross-validation. Finally, the performance metrics of the models erre compared using metrics like Accuracy, Precision, and the True Positive Rate. Results: The best performance was found for the Random Forest, also reaching the highest values for Accuracy (88.03%), TP Rate (88%), and Precision (88.10%), showing its robustness in handling maternal health risk classification. The mid-risk category was the most challenging across all the models, characterized by lowered Recall and Precision scores, hence underlining class imbalance as one of the bottlenecks in performance. Conclusions: Machine learning algorithms hold strong potential for improving maternal health risk prediction. The findings underline the place of machine learning in advancing maternal healthcare by driving more data-driven and personalized approaches.

Association of Ambient Air Pollution and Temperature Exposure with Placental Abruption: A Nested Case-Control Study Based on Live Birth Registrations

BACKGROUND

Placental abruption, a rare disorder of unclear etiology, lacks evidence to illustrate its relationship with exposure to air pollution and temperature.

OBJECTIVE

This study aimed to investigate the association between exposure to ambient pollutants and temperatures and placental abruption to identify susceptible time windows and subpopulations.

METHODS

A nested case-control study was based on a live birth registration database in Chongqing, the largest Chinese municipality in China, from 2018 to 2022. The placental abruption cases were each matched with four controls by maternal age at delivery, gestational week, gravidity, parity, and delivery date. Six ambient pollutants [particulate matter (PM) with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ), PM with aerodynamic diameter ≤ 10 μ m (PM 10 ), NO 2 , CO, O 3 , and SO 2 ] and temperature were estimated using machine learning algorithms. A conditional logistic regression model analyzed associations of exposure to air pollution and temperature with placental abruption in five time windows (prepregnancy, the entire pregnancy, and each of the 3 trimesters). Stratification analyses were applied to examine potential modifiers including gravidity, parity, mothers' residential area (urban/rural), pandemic experience, and delivery season.

RESULTS

After data quality control, 798 cases were identified and matched with 3,192 controls. An exposure relationship was identified between NO 2 during the pregnancy period and placental abruption (p < 0.001 ). In comparison with the first quartile level of NO 2 , the odds ratios (ORs) of abruption associated with exposure to the second, third, and fourth quartile levels of NO 2 were 1.42 [95% confidence interval (CI): 1.03, 1.96], 1.90 (95% CI: 1.30, 2.76), and 2.27 (95% CI: 1.39, 3.71), respectively. The association for NO 2 exposure existed in the 3 trimesters but not prepregnancy. Exposure to locally extreme low temperatures (< fifth percentile) in the third trimester was associated with increased risks of abruption (OR = 3.68 ; 95% CI: 1.67, 8.08) in comparison with locally moderate temperatures (25th-75th percentile). Stratified analysis showed no statistical significances within the effect modifiers.

DISCUSSION

Based on a large-scale live birth record, the study suggested that exposure to air pollutants, mainly NO 2 , during pregnancy may be a substantial risk factor for placental abruption. https://doi.org/10.1289/EHP14714.

Association between embryo transfer season and the risks of hypertensive disorders of pregnancy and gestational diabetes mellitus

PURPOSE

To explore the impact of seasonal variations on the risks of hypertensive disorders of pregnancy (HDP) and gestational diabetes mellitus (GDM) in women who undergo in vitro fertilization (IVF) treatment.

METHODS

We retrospectively included a total of 21,469 women who achieved singleton delivery during their first cycles of IVF, the risks of HDP and GDM were compared in different seasonal groups according to the time of embryo transfer and the time of oocyte retrieval.

RESULTS

After adjustment via multivariable logistic regression, women who underwent embryo transfer in spring with the expected date of confinement in winter had a higher risk of HDP (4.9% vs. 3.8%; adjusted odds ratio (aOR), 1.34; 95% confidence interval (CI), 1.09-1.64; P = 0.005) than those underwent embryo transfer in winter with the expected date of confinement in autumn. There were no seasonal variations in the risk of HDP according to the time of oocyte retrieval or in the risk of GDM regardless of the time of embryo transfer or the time of oocyte retrieval. After subgroup analysis, the seasonal variations in the risk of HDP remained in frozen embryo transfer (FET) cycles but not in fresh embryo transfer (FreET) cycles.

CONCLUSIONS

The risk of HDP was increased in women who underwent embryo transfer in spring compared to those who underwent embryo transfer in winter. The risk of HDP is more likely to be affected by the season at the time of embryo transfer in FET cycles compared to FreET cycles.

Heat Waves and Early Birth: Exploring Vulnerability by Individual- and Area-Level Factors

Extreme heat has been linked to many health outcomes, including preterm and early term birth. We examine associations between acute heat wave exposure and risk of preterm (PTB) (28-36 weeks) or early term (ETB) (37-38 weeks) birth, stratified by individual-level and area-level factors. Daily ambient mean temperature was linked to maternal residence in state vital records for preterm and early term births in California, Florida, Georgia, Kansas, Nevada, New Jersey, North Carolina, and Oregon between 1990 and 2017. Heat waves were identified during the four-day exposure window preceding birth using the 97.5th percentile mean temperature for zip code tabulation areas (ZCTA). We used a time-stratified case-crossover design, restricted to the warm season (May through September) and stratified by maternal age, maternal education, ZCTA-level impervious land cover or social deprivation index. We pooled estimated odds ratios across states using inverse-variance weighting. The PTB and ETB analyses included up to 945,836 and 2,966,661 cases, respectively. Heat-related ETB risk was consistently highest among women <25 years of age, women with ≤high school education, and women living in areas of higher social deprivation and impervious land cover. PTB associations were also elevated in these subgroups, but positive associations were also observed among older, more educated mothers, and in areas with less social deprivation. Across all subgroups and outcomes, the change in odds associated with heat waves ranged from no increase to a 7.9% increase. Heat-related early term birth risk is enhanced among subgroups associated with socioeconomic disadvantage, but patterns of vulnerability were less consistent for preterm birth.

Exploring heat risk in pregnant women: do environmental and social inequalities amplify heat exposure?

Heat exposure in pregnancy has been associated with mother-child health. However, characterization of exposure to heat in pregnant women and its associated factors, such as air pollution, vegetation or social stressors, is lacking. We aimed to describe heat exposure according to air pollution and vegetation co-exposures, individual social position and socio-economic context of residence among French pregnant women. We studied 12,235 pregnant women from four mother-child cohorts. Exposure to heat (intensity, duration, severity), particulate matter, nitrogen dioxide (NO2), ozone (O3), and vegetation during summer were estimated at the women's residences. Socio-economic context of residence was assessed using the European Deprivation Index (EDI). Cumulative overexposure to heat, air pollution and vegetation were estimated according to reference values. Three profiles of heat exposure, multi-exposure and individual social position, were created using multivariate analysis and unsupervised clustering. Associations of the profiles of heat exposure and multi-exposure with air pollution, vegetation, individual social position and EDI were described using Wilcoxon tests and polytomous regressions. About one-third of pregnant women had a high heat exposure profile combining intense, severe and durable exposure. Depending on the location and year of pregnancy, 27-88% of women were overexposed to heat, air pollution and lack of vegetation. The relationships between profiles of heat and multi-exposure with air pollution, vegetation and individual social position and socioeconomic context of residence depended on the geographical and temporal context. No clear differential exposure pattern across social strata was found. Co-exposure to heat, air pollution and lack of vegetation is common among French pregnant women. Protective measures against summer heat would apply to all pregnant women, as heat exposure represents a universal risk, regardless of socioeconomic status. This research supports future epidemiological studies on combined effects of heat and co-exposures on pregnancy outcomes.

Mapping multilevel adaptation response to protect maternal and child health from climate change impacts: A scoping review

Anthropogenic climate change attributed increases in air pollution, rising temperatures, and extreme weather events are linked to a higher risk of adverse pregnancy and birth outcomes, necessitating interventions to protect maternal and child health. This scoping review mapped multilevel adaptation strategies implemented to protect maternal and child health from climate change effects. Eighteen unique adaptation strategies we identified included educational interventions, risk communication, air purifiers, air cleaning strategies, nutrition supplementation, cash transfer, employment guarantee scheme, community health worker program, chemoprophylaxis, insecticide-treated nests, home and environmental remediation, and bioethanol cooking fuel. Our findings suggest that these adaptation strategies are generally nonspecific and fail to address the specialized needs and unique health risks faced by pregnant women and young children. Prioritizing the involvement of pregnant women, mothers of young children and local healthcare services in developing tailored adaptation interventions is crucial to support climate change adaptation, resilience, and reducing maternal and child health risks.

Can nutraceuticals counteract the detrimental effects of the environment on male fertility? A parallel systematic review and expert opinion

INTRODUCTION

Male fertility relies on a complex physiology that may be negatively influenced by lifestyle, diet, and environment. The beneficial effect of nutraceuticals on male fertility is a debated claim. The aim of this study was to assess if the positive effect of nutraceuticals can counteract the negative effects of the environment on male fertility.

EVIDENCE ACQUISITION

PubMed®/MEDLINE®, Embase and Cochrane Database were searched (September-October 2023), along with crosschecking of references and search for ongoing studies of the effects of the environment and nutraceuticals on male fertility, in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

EVIDENCE SYNTHESIS

Several environmental factors such as microplastic and other endocrine-disrupting chemicals and climate changes may affect the sperm quality in terms of reduction of sperm count number, mobility and altered morphology and thereby reduce male fertility. On the other hand, new evidence demonstrates that a balanced diet rich in antioxidants and essential nutrients, together with minimized exposure to environmental toxins, may improve male fertility and reproductive health. Several nutraceutical compounds proved a protective role against negative environmental effects on male fertility.

CONCLUSIONS

Available evidence confirms that the environment may negatively impact male fertility, and this impact is estimated to rise in the forthcoming years. On the other hand, new data indicate that nutraceuticals may have a protective role against the negative impact of environmental factors on male fertility. The need for future studies to monitor and explore these aspects of men's health cannot be underestimated.

Impact of air pollution and climate change on maternal, fetal and postnatal health

OBJECTIVE

Besides socioeconomic factors, environmental pollution, and climate change are contemporary threats to health. In this review, the authors present results from a recent comprehensive synthesis of existing research on the effects of air pollution and climate change on gestation, fetal development, and postnatal health.

DATA SOURCES

Findings from systematic reviews conducted over the past five years and available in PubMed were used.

SUMMARY OF FINDINGS

A vast and robust evidence exists on the association between air pollution exposures and negative outcomes. Gestational diabetes, hypertensive disorders of pregnancy, preeclampsia, spontaneous abortion, and maternal postpartum depression are reported. Fetal development and postnatal health are also impaired by exposures; low birth weight is a common finding from studies worldwide, but there are increased risks for malformations and impairments in neurodevelopment. While there are fewer studies on factors related to climate change, there is sufficient evidence regarding the direct and indirect effects on maternal health and fetal development. Increased risks for prematurity, low birth, and emergency room visits are associated with higher temperatures. Asthma incidence and infectious respiratory disease risks are also influenced by extreme weather events. It is essential to recognize the profound impact that environmental factors, such as air pollution and climate change can have on maternal health, fetal development, and neonatal health.

CONCLUSION

The data presented underscores the significant risks that environmental pollution poses during gestation, influencing not only maternal health but also the short- and long-term well-being of the child.

Imaging Climate-Related Environmental Exposures: Impact and Opportunity

Climate change is the most important challenge of this century. Global surface temperature is continuously rising to new record highs, adversely affecting the health of the planet and humans. The purpose of this article is to review the impact of climate related environmental exposures on human health, healthcare delivery, and medical imaging and explore the potential to leverage medical imaging as a non-invasive tool to advance our understanding of climate related health effects. Radiology departments and healthcare systems must focus on building resilience to the effects of climate change while ensuring that the delivery of care is environmentally sustainable. Further research is needed to refine our understanding of the effects of climate change on human health and to forecast the expected changes in the demand for healthcare and radiology services.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Seasonal Influences on Human Placental Transcriptomes Associated with Spontaneous Preterm Birth

Demographic studies have revealed a strong association between exposure to high ambient temperatures during pregnancy and increased risks of preterm birth (PTB). The mechanism underlying this association is unclear, but it is plausible that altered placental function may contribute to it. In this study, we conducted differential gene expression analysis, gene set enrichment analysis (GSEA), and gene ontology (GO) analysis on bulk RNA-seq data from human placentas delivered at term and preterm during the warmer months compared to placentas delivered at term and preterm during the colder months in the UK. We detected 48 differentially expressed genes in preterm placentas delivered during the warmer months compared to preterm placentas delivered during the colder months, the majority of which were inflammatory cytokines and chemokines, including SERPINA1, IL1B, CCL3, CCL3L3, CCL4, CCL4L2, CCL20, and CXCL8. The GSEA positively enriched 17 signalling pathways, including the NF-κB, IL17, Toll-like receptor, and chemokine signalling pathways in preterm placentas delivered during warmer months. These results were not observed in the placentas delivered at term during the same times of the year. The GO analysis revealed several enhanced biological processes, including neutrophil, granulocyte, monocyte, and lymphocyte chemotaxis, as well as inflammatory and humoral immune responses in preterm placentas, but not in placentas delivered at term in the summer. We conclude that maternal exposure to warm environmental temperatures during pregnancy likely alters the placental transcriptomes towards inflammation and immune regulation, potentially leading to PTB.

The association of temperature extremes, ecosystem resilience, with child mortality: Novel evidence from India

The present study investigates how ecosystem resilience affects children's health and acts as a protective shield against high temperature exposure. Ecosystem resilience is the ability of an ecosystem to absorb anthropogenic or climatic shocks and recover from those shocks. The study used various data sources to estimate the impact of temperature extremes on child mortality in India. Data on neonatal mortality (NMR) and infant mortality (IMR) were obtained from the National Family Health Survey (NFHS-5) conducted between 2019 and 2021. Satellite data were used to assess extreme heat and ecosystem resilience. Univariate and bivariate Local Indicator of Spatial Autocorrelation (LISA) analysis were applied to examine the spatial association of high temperature, ecosystem resilience, and NMR, IMR. Further, a multivariate Cox hazard model, taking into account the censored data, was used to estimate mortality risk in high temperatures and non-resilient ecosystems. The spatial regression model reveals a significant association between higher temperatures and higher NMR (β: 1.78) and IMR (β: 1.79). The cox-proportional hazard models show elevated risks for neonatal and infant deaths due to high temperatures and non-resilient ecosystems. The resilience of the ecosystem plays an important role in exerting a positive effect on children's health, though, at its current state, resilience fails to moderate the high temperature impact on mortality. The present study, the first of its kind in India, highlights the exposure to high temperatures leading to neonatal and infant deaths when reliance imparts limited protective effect to offshoot the impact of high temperature on excess mortality.

Interventions to reduce the effects of air pollution and of extreme heat on maternal, newborn, and child health outcomes: a mapping of the literature

Background

There is an increasing awareness of the ongoing and projected impacts of air pollution and of extreme heat on maternal, newborn, and child health (MNCH) outcomes, showing significant short and long-term health problems. There is a dearth of information available for policy makers on interventions that have been implemented to reduce the impact on MNCH, impeding the integration of action into health planning. This paper presents an inventory of interventions aimed at reducing the effects of these two climate hazards on MNCH.

Methods

We conducted a scoping review of articles published in three databases and grey literature to identify and map interventions implemented to address the impact of air pollution and/or extreme heat on MNCH. Items were included if published between January 2016 and November 2022, regardless of language, and as this is an inventory, regardless of if the intervention was evaluated. Over 32 700 journal items were reviewed for inclusion and a sample of grey literature from web-based searches.

Results

A final inventory of 76 items were included. Interventions identified were primarily based in the Global North (n = 51), with the largest proportion in the USA (n = 17), while 32 items were based in the Global South. Fifty-seven items focused on air pollution, 18 on extreme heat, and one on both. Interventions were categorised in four adapted socioecological components: (i) individual and household interventions (n = 30), (ii) community and service interventions (n = 18), (iii) structural interventions and urban landscape interventions (n = 15), (iv) policy interventions (n = 16). Most items were focused on child health outcomes (n = 65); 61 items were evaluated.

Conclusions

This scoping review maps interventions implemented and proposes a categorisation of these to initiate reflections and dialogue on what has been done and how to start building an evidence base. The review also highlights gaps in interventions and the knowledge base, with most interventions implemented to address air pollution, in the Global North and most addressing child health need. As country programmes seek to address the impact of climate change on MNCH, additional efforts are needed to better understand what has been done, document lessons learned, agree on common outcome measurements and feasible study designs for evaluation to start building the evidence base.

The Influence of Heat on Pediatric and Perinatal Health: Risks, Evidence, and Future Directions

Children, particularly infants and those with chronic conditions, are highly vulnerable to heat-induced health risks, similarly to the elderly. This narrative review synthesizes current evidence on the impact of heat exposure on pediatric and perinatal health. A systematic literature search was conducted using PubMed/MEDLINE and manual reference checks, focusing on studies from 2000 to 2024. Findings indicate that maternal heat exposure is associated with adverse pregnancy outcomes, including pre-eclampsia, gestational diabetes, hypertension, and increased hospital admissions. Additionally, prenatal heat stress correlates with preterm birth, low birth weight, birth defects, and stillbirth. In childhood, heat-related health consequences range from heatstroke and dehydration to renal impairment, respiratory diseases, and gastrointestinal infections. Psychosocial effects, including cognitive impairment, sleep disturbances, and mental health issues, have also been reported in school-age children and adolescents. Despite strong epidemiological evidence, critical knowledge gaps remain, including the exact temperature thresholds that increase disease risk and how these thresholds vary by age and underlying health conditions. Urgent public health measures are required to mitigate these risks, while further research is needed to define exposure-response relationships and effective interventions. Addressing the rising burden of heat-related pediatric illness is essential in the context of climate change and increasing global temperatures.

Scoping review of climate drivers on maternal health: current evidence and clinical implications

Objective

To systematically review the literature on associations between climate drivers and health outcomes among pregnant people. This review fills a gap by synthesizing evidence for a clinician audience.

Data Sources

Systematic scoping review of articles published in PubMed and clinicaltrials.gov from January 2010 through December 2023.

Study Eligibility Criteria

Empirical studies published in English-language peer-reviewed journals, assessing associations between select climate drivers and adverse maternal and birth outcomes. The review included studies examining heat, storms, sea level rise, flooding, drought, wildfires, and other climate-related factors. Health outcomes included preterm birth, low birthweight, small for gestational age, gestational diabetes, pre-eclampsia/eclampsia, miscarriage/stillbirth and maternal mortality.

Study Appraisal and Synthesis Methods

The scoping review protocol was registered with the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY202410004, January 3, 2024) and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Data were extracted by 2 authors; quality and risk of bias was assessed independently.

Results

Total of 966 references were screened; 16.35% (k=158) met inclusion criteria. The majority of studies (146/158; 92.4%) documented statistically significant and clinically meaningful associations between climate drivers and adverse perinatal health outcomes, including risk of preterm birth, low birthweight, and stillbirth as well as preeclampsia, gestational diabetes, miscarriage, and maternal death. Among the most durable findings: extreme heat exposure in early and late pregnancy were associated with increased risk of preterm birth and stillbirth. Driven in part by large (often population-based) studies and objective outcomes from surveillance data or medical record reviews, studies in this scoping review were evaluated as high quality (scoring 7-9 on the Newcastle-Ottawa Scale). Risk of bias was generally low.

Conclusions

Climate drivers are consistently associated with adverse health outcomes for pregnant people. Continuing education for clinicians, and clinician-patient communications should be expanded to address risks of climate change and extreme weather exposure, especially risks of extreme heat in late-pregnancy. Results from this review should inform multilevel interventions to address adverse health effects of climate during pregnancy as well as practice advisories, protocols, checklists, and clinical guidelines in obstetrics.

Prenatal ambient temperature exposure and cord blood and placental mitochondrial DNA content: Insights from the ENVIRONAGE birth cohort study

BACKGROUND

Mitochondrial DNA content (mtDNAc) at birth is a sensitive biomarker to environmental exposures that may play an important role in later life health. We investigated sensitive time windows for the association between prenatal ambient temperature exposure and newborn mtDNAc.

METHODS

In the ENVIRONAGE birth cohort (Belgium), we measured cord blood and placental mtDNAc in 911 participants using a quantitative real-time polymerase chain reaction. We associated newborn mtDNAc with average weekly mean temperature during pregnancy using distributed lag nonlinear models (DLNMs). Double-threshold DLNMs were used to study the relationships between ambient temperature and mtDNAc below predefined low (5th, 10th, 15th percentile of the temperature distribution) and above predefined high temperature thresholds (95th, 90th, 85th percentile of the temperature distribution).

FINDINGS

Prenatal temperature exposure above the used high temperature thresholds was linked to lower cord blood mtDNAc, with the strongest effect in trimester 2 (cumulative estimates ranging from -21.4% to -25.6%). Placental mtDNAc showed positive and negative associations for high temperature exposure depending on the applied high temperature threshold. Negative associations were observed during trimester 1 using the 90th and 95th percentile threshold (-26.1% and -33.2% lower mtDNAc respectively), and a positive association in trimester 3 when applying the most stringent 95th percentile threshold (127.0%). Low temperature exposure was associated with higher mtDNAc for both cord blood and placenta. Cord blood mtDNAc showed a positive association in trimester 2 when using the 10th percentile threshold (11.3%), while placental mtDNAc showed positive associations during the whole gestation and for all applied thresholds (estimates ranging from 80.8% - 320.6%).

INTERPRETATION

Our study shows that in utero temperature exposure is associated with differences in newborn mtDNAc at birth, with stronger associations observed in the placenta. These findings highlight the impact of prenatal ambient temperature exposure on mtDNAc during pregnancy.

A systematic review and meta-analysis of heat exposure impacts on maternal, fetal and neonatal health

Climate change has severe and wide-ranging health impacts, especially for vulnerable groups. Despite growing evidence of heat-associated adverse maternal and neonatal health outcomes, there remains a lack of synthesis quantifying associations and identifying specific risk periods. We systematically reviewed the literature on heat impacts on maternal, fetal and neonatal health and quantified impacts through meta-analyses. We found 198 studies across 66 countries, predominantly high income (63.3%) and temperate climate zones (40.1%), and 23 outcomes. Results showed increased odds of preterm birth of 1.04 (95% confidence interval (CI) = 1.03, 1.06; n = 12) per 1 °C increase in heat exposure and 1.26 (95% CI = 1.08, 1.47; n = 10) during heat waves. Similarly, high heat exposure increased the risk for stillbirths (odds ratio (OR) = 1.13 (95% CI = 0.95, 1.34; n = 9)), congenital anomalies (OR = 1.48 (95% CI = 1.16, 1.88; n = 6)) and gestational diabetes mellitus (OR = 1.28 (95% CI = 1.05, 1.74; n = 4)). The odds of any obstetric complication increased by 1.25 (95% CI = 1.09, 1.42; n = 11) during heat waves. Patterns in susceptibility windows varied by condition. The findings were limited by heterogeneity in exposure metrics and study designs. The systematic review demonstrated that escalating heat exposure poses a major threat to maternal and neonatal health, highlighting research priorities, guiding the selection and monitoring of heat-health indicators and emphasizing the need to prioritize maternal and neonatal health in national climate health programs.

Maternal exposure to ambient temperature and risk of preterm birth in Chengdu, China, from 2017 to 2020: a cohort study

BACKGROUND

Due to climate change, the frequency and intensity of heat waves and other extreme weather events are rapidly increasing. Compared to the general population, pregnant women and fetuses are increasingly vulnerable to the effects of extreme temperatures and are associated with the occurrence of adverse birth outcomes, including preterm birth (PTB). However, its risk of preterm birth is currently uncertain. The objective of the research is to examine the effect of ambient temperature on PTB in pregnant women.

METHODS

This study included 6,850 pregnant women from the Tongji-Shuangliu Birth Cohort. Meteorological data for Chengdu through the European Centre for Medium-Range Weather Forecasts. The main exposure assessment was conducted during eight different exposure windows, including the first three months of pregnancy, 7 weeks periods during the first two trimesters, throughout pregnancy, 1-week preceding delivery, and 4 weeks preceding delivery. The effect of environmental temperature on PTB during different exposure windows was assessed using the logistic regression based on the percentile of the mean temperature in different exposure cycles. Additionally, the lagged effect of environmental temperature on preterm births throughout the study period was analyzed using a distributed lag non-linear model.

RESULTS

Among the 6850 pregnant women, 301 (4.4%) were diagnosed with PTB. Compared to mild temperature (10th to 90th percentile), exposure to extreme cold (< 10th percentile) temperature during the 4 weeks preceding delivery (RR = 2.45, 95% CI:1.11,5.40) and throughout pregnancy (RR = 3.85, 95% CI:1.56,9.53) increased the risk of PTB. In addition, hot temperature (> 90th percentile) at 4 weeks preceding delivery (RR = 0.33, 95% CI:0.13,0.86) and 22-28 weeks of pregnancy (RR = 0.25, 95% CI:0.11,0.59), and cold exposure at 1-week preceding delivery(RR = 0.51, 95% CI:0.27,0.96), reduced risk of PTB. In the lagged model, compared with 18° C (50th percentile), 7 °C (10th percentile) had the strongest effect on lag day 21 and lag 22 (RR = 1.20, 95% CI:1.03,1.40; RR = 1.20, 95% CI:1.03,1.39). A temperature of 27° C (90th percentile) was protective for PTB from the 22nd day of lag(RR = 0.86, 95% CI:0.75,0.99).

CONCLUSIONS

This study indicates that high temperature may be a protective factor for PTB, while low temperature may be a risk factor, with an obvious lag effect.

The connection between climate change and perinatal mental health

Climate change and extreme weather events are particularly concerning for pregnant and postpartum women and have been related to negative birth outcomes. However, the impact of climate change on perinatal mental health outcomes is not well studied. Mood and anxiety disorders are among the leading comorbidities during pregnancy and the postpartum period, and they are associated with significant familial and societal burdens. It is crucial to include environmental factors in the risk profile of perinatal mental illness to optimize prevention and early intervention strategies. In the clinical experience of one of the authors, new mothers can feel particularly concerned about their baby's physical health when faced with extreme heat or may present as agitated due to heat-related sleep deprivation. This is in line with qualitative research showing maternal worrying about a baby's thermal dysregulation as one of the emerging themes. With extreme weather events becoming more frequent, clinicians have a role in advocating for climate adaptation in healthcare settings. Climate inequalities need to be addressed alongside health and social inequalities.

Coexposure to ambient air pollution and temperature and its associations with birth outcomes in women undergoing assisted reproductive technology in Fujian, China: A retrospective cohort study

BACKGROUND

The interactions between pollutants and temperature coexposure, the mixing effects and their potential mechanisms remain uncertain.

METHODS

This retrospective cohort study included 11,766 women with infertility who received treatment at Fujian Hospital between 2015 and 2024. The daily mean concentrations of the six pollutants and the relative humidity and temperature data were acquired from the Fujian region. Data on genes were obtained from the Comparative Toxicogenomics Database.

RESULTS

O3 (aOR=0.80, 95 % CI=0.725--0.891) and temperature (aOR=0.936, 95 % CI=0.916--0.957) were negatively correlated with live birth rates. Moreover, PM10 (aOR=1.135, 95 % CI=1.028--1.252) and PM2.5 (aOR=1.146, 95 % CI=1.03--1.274) were positively associated with preterm birth. Among the effects on live births, PM2.5, PM10, NO2, CO, and SO2 had significant synergistic effects with temperature; in addition, O3 had significant antagonistic effects with temperature. A notable trend toward declining live birth rates with elevated concentrations of mixed pollutants was observed. Different infertility patients have different sensitivities to coexposure. Gene enrichment and cell experiments are associated mainly with cellular life activities.

CONCLUSIONS

Individual effects, interactions, and mixed effects between temperature and air pollutants and birth outcomes persist when air pollutant levels are relatively low. AAP may trigger miscarriage through cytotoxic effects.

A case-crossover study of air pollution exposure during pregnancy and the risk of stillbirth in Tehran, Iran

The growing fetus is very sensitive to environmental conditions. There is limited and conflicting evidence about the short-term effects of exposure to air pollutants on the pregnancy outcome. In this time-stratified case-crossover study, the effect of several air pollutants (i.e. O3, CO, NO2, SO2, and PM2.5) on the occurrence of stillbirth was evaluated in Tehran (the capital of Iran) between December 2018 and March 2023. Using a quasi-Poisson regression model and distributed lag nonlinear models (DLNM), we estimated the effect of exposure to air pollutants measured as lags (0 to 7 days) and cumulative average days (0-2, 0-6, and 0-14-day lag) before delivery on stillbirth. The association was adjusted for potential confounding factors including meteorological factors. During the study period in Tehran, 5311 stillbirths were reported. In single-pollutant models, during the entire year, SO2 (lag 1 day) and NO2 (lag 2 days) were found to have a direct and significant relationship with stillbirth. In the warm seasons, we found direct and inverse relationships between NO2 (lag 2 days) and PM2.5 (lag 4 days), respectively. In cold seasons, PM 2.5 (lag 1 day) and cumulative lag (0-2 days), SO2 (lag 1 day), and cumulative lag (0-2 and 0-6 days) were found to have direct and significant relationships with stillbirth. In two-pollutant models, SO2 & CO, and SO2 & O3, direct and significant associations were observed between SO2 exposures and stillbirth for the entire year. A similar pattern was observed for PM2.5 in combinations with NO2, and O3 and for NO2 in the two-pollutant model (O3 & NO2). However, in warm seasons, inverse associations were observed between PM2.5 and stillbirth in combinations with O3, NO2, and SO2, while NO2 showed a direct association in combinations with PM2.5, CO, and O3. In the cold seasons, direct and significant associations were observed between SO2 and stillbirth in model combinations with CO, O3, and NO2. This relationship was observed for PM2.5 in combination with CO, and NO2. Also, for CO in the two-pollutant model of CO & NO2. As a result, this study showed evidence of a relationship between short-term exposure to ambient air pollution before birth, especially SO2, NO2, PM2.5, and CO with increased risk of stillbirth.

Impact of Climate Change Education on Pregnant Women's Anxiety and Awareness

OBJECTIVE

To evaluate the impact of climate change education on pregnant women's climate change awareness and anxiety.

STUDY DESIGN

Quasi-experimental research with pre- and post-test design.

METHODS

This study was conducted among pregnant women who visited a tertiary maternity hospital between April and June 2023 to assess climate change awareness, perception, knowledge, behavioral and policy expectations, and anxiety before and after the introduction of climate change education. The first phase of the study was conducted by distributing a set of questions related to sociodemographics and completing the Climate Change Awareness Scale and the Climate Change Worry Scale, followed by climate change education where pregnant women were exposed to a brochure entitled "Pregnancy and Climate Change". After the intervention, pregnant women were assessed using the same questionnaire.

RESULTS

There was a significant decrease in pregnant women's anxiety regarding climate change (p < 0.001). Participants' awareness (p < 0.001), perception (p < 0.001), knowledge (p < 0.001), and policy expectations regarding climate change significantly increased (p < 0.001), while their anxiety levels decreased (p < 0.001).

CONCLUSION

The study suggests that climate change education may reduce climate change anxiety among pregnant women while also enhancing their awareness, and improving their perceptions, knowledge, behaviors, and policy expectations about climate change.

Climate change and gendered vulnerability: A systematic review of women's health

BACKGROUND

Climate change is an urgent global threat, with women in low- and middle-income countries (LMICs) disproportionately facing adverse health outcomes. Gendered roles, combined with socioeconomic, cultural, and environmental factors, exacerbate women's vulnerabilities, increasing the burden of mental health issues, water insecurity, sanitation challenges, and caregiving responsibilities.

OBJECTIVES

This review seeks to systematically examine the intersection between climate change and gendered health vulnerabilities, with a particular focus on women. It explores how climate change intensifies gender-specific risks and identifies pathways for integrating gender-responsive policies to mitigate both short- and long-term health impacts.

DESIGN

Following Arksey and O'Malley's methodological framework, this systematic review mapped key concepts and evidence from studies conducted between January 2011 and January 2024. The review focuses on identifying the multifaceted health impacts of climate change on women, particularly in LMICs and marginalized communities.

DATA SOURCES AND METHODS

A systematic search was conducted in Web of Science and Scopus databases using key terms and Medical Subject Headings related to climate change, women's health, gender inequality, mental health, water security, sanitation, and caregiving burdens. Studies were screened and selected based on relevance to the predefined criteria, with data extracted on study design, key findings, and limitations.

RESULTS

From 2163 citations screened, 61 studies were included in the final analysis. The review highlights that climate change disproportionately affects women, exacerbating pre-existing gender inequalities. Specific impacts include heightened mental health challenges, adverse maternal and newborn health outcomes, increased water insecurity, and an intensified caregiving burden. Women in LMICs are particularly vulnerable due to reduced access to resources, healthcare, and decision-making platforms, further limiting their adaptive capacities.

CONCLUSION

The findings underscore the critical need for gender-responsive climate policies that address both immediate health impacts and the broader socioeconomic and environmental determinants affecting women. Effective climate adaptation strategies must integrate gender perspectives, ensuring that women's specific vulnerabilities are accounted for in policy frameworks. This review advocates for the empowerment of women through increased access to resources and decision-making, thus enhancing their resilience and adaptive capacity in the face of climate change.

Impact of urban biodiversity and climate change on children's health and well being

In recent decades, biodiversity loss has greatly impacted planetary and human health. Children are at additional risk of adverse effects due to unique biological, developmental, and behavioral factors, as well as their longer exposure to an altered planet as a function of their young age. These effects are heightened for children living in vulnerable socioeconomic conditions. Here, we review the role of biodiversity loss on accelerating the consequences of climate change from the perspective of pediatric health. With the loss of biodiversity's protective role against the consequences of climate change, the adverse effects of the changing planet are impacting pediatric health. For example, trees provide shelter against heat waves, unsealed soil and wetlands mitigate flooding, and rewilded green space hosts high microbial richness and consequently supports immune and mental health. The effects of the loss of biodiversity may impact the discovery and development of novel pharmaceuticals and thus the future of children's medicine as a whole. We also highlight areas for further study and detail efforts that have been made to restore biodiversity, with the aim to improve the current and future health of local pediatric populations. IMPACT: Loss of biodiversity is occurring at a rapid pace affecting the health of the planet and disproportionately pediatric health. This paper describes the role of biodiversity loss in accelerating the impact of climate change on children's health, and highlights particularly vulnerable populations. This paper details steps that can be taken to maintain and restore biodiversity at the local and global levels to protect these populations and pediatric health in general.

Climate-Related Emergencies in Pregnancy

Climate change affects human health broadly and is leading to poor population health outcomes in a number of areas. Among pregnant people specifically, it can contribute to greater risk of health complications. Certain populations are more likely to be exposed to the adverse environmental impacts of climate change, which further amplifies existing health inequities in the United States, including in maternal health. Nurses who work in emergent, acute, and critical care settings must be prepared to care for individuals who are pregnant and experiencing medical emergencies as a result of exposure to extreme heat, air pollution, natural disasters, and infectious diseases that are direct consequences of climate change. To this end, nurses must be ready to recognize, treat, and manage pregnancy complications arising from climate-related conditions, as well as provide patient education on future mitigation strategies and advocacy to reduce its harms.

New York State Climate Impacts Assessment Chapter 07: Human Health and Safety

New Yorkers face a multitude of health and safety risks that are exacerbated by a changing climate. These risks include direct impacts from extreme weather events and other climate hazards, as well as indirect impacts occurring through a chain of interactions. Physical safety, physical health, and mental health are all part of the equation-as are the many nonclimate factors that interact with climate change to influence health outcomes. This chapter provides an updated assessment of all these topics at the intersection of climate change, public health and safety, and equity in the state of New York. Key findings are presented below.

Advancing research on greenspace and climate-sensitive adverse birth outcomes for equity and impact

Environmental epidemiologists are increasingly evaluating whether and how human exposure to vegetation (greenspace) can benefit health. Relatedly, scientists and policymakers have highlighted the need to integrate efforts to address the dual crises of accelerating climate change and rapid loss of biodiversity, including nature-based solutions. Greenspace is one solution that can protect humans from climate-related exposures, including heat, air pollution, and flooding. However, most environmental epidemiology research on greenspace occurs in high-income countries, and adverse birth outcomes, previously associated with greenspace, disproportionately occur in low- and middle-income countries (LMICs). Although epidemiology research using existing survey or administrative data and satellite imagery is important for documenting broad patterns, such research is lacking in LMICs. Further, complementary, community-engaged research to inform interventions and policies is needed so that nature-based solutions with co-benefits for climate mitigation and health are adopted effectively and equitably. We provide suggestions for future research that would increase impact and call for better representation of LMICs and vulnerable communities within high-income countries in research and action on greenspace and climate-sensitive birth outcomes.

The Analysis and the Impact of Surface Temperature Anomalies on the Health of Residents in the River Niger Basin Development Authority Area, West Africa

This study investigates the impact of surface temperature anomalies on the health of residents within the River Niger Basin Development Authority (RIBDA) enclave, which covers Nigeria, Niger, and Mali in West Africa, with a focus on the regional implications for public health. Historical climate data from 1985 to 2014, sourced from the Climatic Research Unit Time-Series, Version 3.22 (CRU TS 3.22), was analyzed to comprehend past climate patterns and establish a baseline for future comparisons. Predictions for future climate conditions (2015-2044) were derived by adjusting the CRU data using temperature projections from the Community Climate System Model 4 under the Representative Concentration Pathway 8.5 scenario. To assess the potential impacts of these climate changes, particularly during the boreal summer season of July-August-September (JAS), the study utilized the Hydrology, Entomology, and Malaria Transmission Simulator (HYDREMATS). Findings indicate that surface temperature can intricately influence disease transmission, with varied effects on parameters such as Ro, EIR, prevalence, and immunity index. Observations revealed fluctuations in temperature anomalies over the years, with negative anomalies in 1991-1995 and positive anomalies in subsequent years. Although precise predictions for 2016-2044 are challenging based solely on data trends from 1985 to 2015, continued temperature rises could potentially lead to increased disease prevalence and decreased immunity index. Moreover, the analysis identified a notable temporal increase in mean annual temperature and mean annual maximum temperature from 1999 to 2020, suggesting a faster warming trend in maximum temperatures compared to minimum temperatures. This increase in temperature variability may alter the onset and cessation dates of the rainy season, affecting water availability, accessibility, and consumption, consequently fostering conditions conducive to health-related diseases. By incorporating predicted long-term temperature changes due to greenhouse gas emissions while maintaining current inter-annual climate patterns, this approach allows researchers to anticipate potential future health implications in the studied regions.

Scoping Review of Climate Change Adaptation Interventions for Health: Implications for Policy and Practice

Climate change is among the greatest threats to health in the 21st century, requiring the urgent scaling-up of adaptation interventions. We aim to summarise adaptation interventions that were funded by the Belmont Forum and the European Union, the largest global funders of climate change and health research. A systematic search was conducted (updated February 2023) to identify articles on adaptation interventions for health within this funding network. The data extracted included study characteristics, types of interventions, and study outcomes. The results were synthesised narratively within the PRISMA-ScR guidelines. A total of 197 articles were screened, with 37 reporting on adaptation interventions. The majority of interventions focused on the general population (n = 17), with few studies examining high-risk populations such as pregnant women and children (n = 4) or migrants (n = 0). Targeted interventions were mostly aimed at behavioural change (n = 8) and health system strengthening (n = 6), while interventions with mitigation co-benefits such as nature-based solutions (n = 1) or the built environment (n = 0) were limited. The most studied climate change hazard was extreme heat (n = 26). Several studies reported promising findings, principally regarding interventions to counter heat impacts on workers and pregnant women and improving risk awareness in communities. These findings provide a platform on which to expand research and public health interventions for safeguarding public health from the effects of climate change.

Added Value of Medical Subject Headings Terms in Search Strategies of Systematic Reviews: Comparative Study

BACKGROUND

The massive increase in the number of published scientific articles enhances knowledge but makes it more complicated to summarize results. The Medical Subject Headings (MeSH) thesaurus was created in the mid-20th century with the aim of systematizing article indexing and facilitating their retrieval. Despite the advent of search engines, few studies have questioned the relevance of the MeSH thesaurus, and none have done so systematically.

OBJECTIVE

The objective of this study was to estimate the added value of using MeSH terms in PubMed queries for systematic reviews (SRs).

METHODS

SRs published in 4 high-impact medical journals in general medicine over the past 10 years were selected. Only SRs for which a PubMed query was provided were included. Each query was transformed to obtain 3 versions: the original query (V1), the query with free-text terms only (V2), and the query with MeSH terms only (V3). These 3 queries were compared with each other based on their sensitivity and positive predictive values.

RESULTS

In total, 59 SRs were included. The suppression of MeSH terms had an impact on the number of relevant articles retrieved for 24 (41%) out of 59 SRs. The median (IQR) sensitivities of queries V1 and V2 were 77.8% (62.1%-95.2%) and 71.4% (42.6%-90%), respectively. V1 queries provided an average of 2.62 additional relevant papers per SR compared with V2 queries. However, an additional 820.29 papers had to be screened. The cost of screening an additional collected paper was therefore 313.09, which was slightly more than triple the mean reading cost associated with V2 queries (88.67).

CONCLUSIONS

Our results revealed that removing MeSH terms from a query decreases sensitivity while slightly increasing the positive predictive value. Queries containing both MeSH and free-text terms yielded more relevant articles but required screening many additional papers. Despite this additional workload, MeSH terms remain indispensable for SRs.

Community perspectives of heat and weather warnings for pregnant and postpartum women in Kilifi, Kenya

BACKGROUND

Extreme weather is a recognised risk factor for stillbirth and preterm birth, disrupts women's access to healthcare during pregnancy and childbirth, and negatively affects the care of newborns. Reliable and accessible heat and weather warning systems are key in alerting individuals to undertake protective measures. There is a notable gap in understanding how women and caregivers in rural East Africa perceive and utilize weather information. We investigated community members' heat and weather warning information-seeking behaviour, identified available sources, assessed their reliability and utility, and examined their influence on behaviour.

SETTINGS

Our research was conducted in rural Kilifi County in Kenya's coastal region. The area experiences temperatures exceeding 23°C throughout the year, with extended periods of extreme temperatures [> 40°C] and long and severe droughts.

METHODS

We conducted in-depth interviews [IDI] with pregnant and postpartum women [n = 21] and held six focus group discussions [FGDs] involving mothers-in-law and community health volunteers [CHVs]. The data were analysed in NVivo 12 using both inductive and deductive approaches.

RESULTS

We found significant gaps concerning pregnant and post-partum women, and their caregivers, having timely access to weather forecasts and heat information from health or meteorological authorities. Information on heat and weather warnings is disseminated through various channels, including television, radio, mobile phones, and word of mouth, which are facilitated by community influencers such as CHVs and local chiefs. Indigenous methods of weather forecasting, such as cloud observation, consulting local "rainmakers", and studying the behavioural patterns of amphibians, are employed in conjunction with warnings from the Kenyan Meteorological Department (KMD). Barriers to accessing weather information include the cost of television and smartphones and a lack of segmented information in local languages.

CONCLUSIONS

National and county meteorological services need to enhance public participation, communication, and the delivery of heat and weather information to guide community-level response measures and individual behaviour change. They should also collaborate with health professionals to address heat risks for vulnerable groups. Further research is needed to empower indigenous weather predictors with modern weather information and revise national policies to deliver tailored messages to vulnerable populations like pregnant and postpartum women.

Prenatal ozone exposure and risk of intellectual disability

BACKGROUND

Knowledge of relationships between tropospheric ozone and mental and developmental health outcomes is currently inconclusive, with the largest knowledge gaps for children. This gap is important to address as evidence suggests that climate change will worsen ozone pollution.

OBJECTIVE

We examine the association of average ozone exposure during the preconception period, and first, second and third trimesters of pregnancy on the odds of intellectual disability (ID) in Utah children.

METHODS

For the period of 2002-2020, we assembled daily, tract-level ozone concentration data, data on ID case status, and data on cases' full siblings and population controls. We analyzed the data using generalized estimating equations.

RESULTS

Ozone was positively associated with the odds of ID in cases vs. their siblings (in the preconception, first, second and third trimester exposure windows, all p < 0.05, n = 1042) and vs. population controls (only in the second trimester exposure window, p < 0.05, n = 5179). The strength of the association was largest during the second trimester in both analyses. A second trimester average ozone level increase of 10 ppb was associated with a 55.3% increase in the odds of ID relative to full siblings (95% confidence interval [CI]: 1.171-2.058) and a 22.8% increase in the odds of ID relative to population controls (CI: 1.054-1.431). Findings were robust to different subsets of sibling controls as well as several sensitivity analyses.

SIGNIFICANCE

Results document that ozone has a measurable relationship with children's cognitive development in Utah.

IMPACT STATEMENT

Evidence suggests that climate change will worsen ozone pollution. The potential amplifying effect of climate change on ozone is more certain than it is for fine particulate matter. This means that ozone and health research will remain relevant into the future. Currently, several systematic reviews and meta-analyses have concluded that knowledge about ozone and cognitive health is insufficient, especially for children. Using two different study designs, we find that prenatal ozone exposure is associated with risk of intellectual disability in children.

Vitamin D concentration in maternal serum during pregnancy: Assessment in Hokkaido in adjunct study of the Japan Environment and Children's Study (JECS)

BACKGROUND

Vitamin D is an essential nutrient for maintaining blood calcium and phosphorus levels and controlling bone density. Deficiency in it leads to rickets, osteomalacia, osteoporosis, and various other diseases. Recently, it has gained attention for reportedly reducing the risk of COVID-19 severity. However, there are no reports evaluating pregnant women in the Hokkaido region of Japan. This study aims to elucidate the current status of vitamin D levels in pregnant women in the Hokkaido region.

METHODS

This study measured the serum concentrations of Vitamin D2 and D3 in 206 pregnant women participating in the Japan Environment and Children's Study-Hokkaido sub-cohort at the Hokkaido Regional Center. It analyzed the relationship between these concentrations and the months, seasons, and sunshine hours.

RESULTS

The mean maternal age was 31.7 ± 4.7 years, and the mean prepregnancy BMI was 21.0 ± 2.5 kg/m2. Only two women have given birth at least once. Regarding sunscreen use, 65 participants (31.6%) responded "often" or "sometimes." Five women used the supplement containing Vitamin D. The value of 25(OH)D2 was above 1 ng/ml in four of them. The average 25(OH)D3 level was 12.1 ng/ml, with a median of 11.0 ng/ml. Four participants (1.9%) had levels below 5 ng/ml. The highest median of 25(OH)D3 was in July, and the lowest was in April. The concentration of 25(OH)D3 was significantly higher in summer than in winter. A correlation was found between 25(OH)D3 and sunshine hours, with 25(OH)D3 concentrations gradually increasing as sunshine hours increase.

CONCLUSION

It was found that almost all pregnant women in Hokkaido were deficient in vitamin D. It is necessary to implement measures to enhance vitamin D levels in pregnant women to safeguard the health of women and fetuses in Hokkaido.

Establishing a Multifaceted Comprehensive Maternity Cohort Facilitates Understanding of How Environmental Exposures Impact Perinatal Health

China's "three-child policy", implemented in response to population aging, has made the protection of maternal and infant health an urgent priority. In this environmental and medical big-data era, the Zhejiang Environmental and Birth Health Research Alliance (ZEBRA) maternity cohort was established with the aim of identifying risk factors for perinatal morbidity and mortality from the perspectives of both observational epidemiology and experimental etiology. Compared with conventional birth cohorts, the inclusion of a maternity cohort allows greater scope for research and places an emphasis on maternal health. In particular, it allows us to focus on pregnant women with a history of pregnancy-related illnesses and those planning to have a second or third child. There are currently many pressing issues in perinatal health, including the risk associations between exogenous together with endogenous factors and the occurrence of perinatal abnormalities, pregnancy complications, and adverse pregnancy outcomes. It is crucial to explore the interaction between environmental exposures and genetic factors affecting perinatal health if we are to improve it. It is also worthwhile to assess the feasibility of the early stage prediction of major perinatal abnormalities. We hope to study this in the ZEBRA cohort and also seek nationwide and international collaborations to establish a multicenter cohort consortium, with the ultimate goal of contributing epidemiological evidence to literature and providing evidence-based insights for global maternal and child healthcare.

Development, validation and reliability of scales and items for heat wave risk assessment of pregnant women

INTRODUCTION

The 1.2 °C rise of global ambient temperature since the pre-industrial era has led to an increase the intensity and frequency of heatwaves. Given the heightened vulnerability of pregnant women to heat stress, there is an urgent need for tools which accurately assess the knowledge, risk, and perception of pregnant woman toward heatwaves, enabling effective policy actions. In this research, we developed and validated tools to evaluate pregnant women's perceptions of heat wave risks and behaviors.

METHOD

We developed 50 items across seven constructs using the Health Belief Model, identified through a systematic literature review. The constructs comprised 8 Knowledge(K) items, 4 in Perceived Vulnerability (PV), 5 in Perceived Severity (PS), 6 in Perceived Benefit (PB), 4 in Perceived Barrier (PBa), 5 in Cue to Action(Cu) and 18 in Adaptation(A). Cognitive testing was performed with a separate group of pregnant women(n = 20). The tested tools were then administered to 120 pregnant women residing during the spring-summer 2023. Construct validation utilized exploratory factor analysis.

RESULTS

The Principal Axis Factoring Method was employed in the EFA with oblimin rotation for 51 items, considering communality > 0.20, and aiming to extract three factors. Across the three factors with Cronbach's alpha > 0.70, a total of 11 items were distributed. Factor 1 included Perceived Severity (PS1, PS2, PS3 and PS5); Factor 2 included Cue to Action (Cu1, Cu2, Cu3, and Cu4); and Factor 3 encompassed Perceived Vulnerability (PV1, PV2, PV4). Only two of the retained items had factor loadings > 0.50, namely PV4 and PS5. Consequently, the three constructs measuring Perceived Severity, Cues to Action, and Perceived Vulnerability using the HBM among pregnant women were deemed valid.

CONCLUSION

Our study has successfully validated a highly reliable tool which stands ready for application in assessing pregnant women's risk perception regarding heatwaves.

Development and Testing of the Comprehensive Prenatal Care Index: Relationship With Preterm Birth and Small for Gestational Age Across Racial and Ethnic Groups

INTRODUCTION

Preterm birth and small for gestational age (SGA) are significant public health concerns in the United States, with pronounced disparities across racial and ethnic groups. Traditional prenatal care adequacy indices have limitations in fully capturing their multifaceted nature. Our study introduces the Comprehensive Prenatal Care Index (CPCI) to provide a more holistic assessment of prenatal care by integrating key elements of prenatal counseling and health promotion.

METHODS

This cross-sectional study used the Pregnancy Risk Assessment Monitoring System 2016-2021 data. The CPCI was developed based on a comprehensive literature review, incorporating components such as timing, frequency, and content of prenatal visits. The index was validated using Item Response Theory (IRT) and compared with the Kotelchuck and Kessner Indices.

RESULTS

The study included 139,181 pregnant women. The CPCI demonstrated strong internal consistency (Cronbach's α, 0.75; ω total, 0.81). IRT analysis confirmed the index's ability to capture variability in the quality of prenatal care, with item difficulty parameters ranging from -2.93 to +2.10. CPCI scores were significantly associated with reduced odds of adverse birth outcomes. Adequate CPCI care was linked to a 63% reduction in the odds of preterm birth among non-Hispanic White women, with similar reductions observed in Hispanic women (odds ratio [OR], 0.59) and Asian women (OR, 0.38). For SGA, adequate care was protective among non-Hispanic White (OR, 0.86) and Hispanic women (OR, 0.82) but showed mixed results in other groups.

DISCUSSION

The CPCI provides a more inclusive measure of the quality of prenatal care compared with traditional indices. The study's findings suggest a significant role of comprehensive prenatal care in reducing adverse birth outcomes and addressing racial and ethnic disparities. Future research should focus on refining the CPCI and exploring its applicability in diverse populations to inform targeted and culturally sensitive prenatal care strategies.

Health effects of selected environmental Exposomes Across the Life courSe in Indian populations using longitudinal cohort studies: GEOHealth HEALS Study protocol

INTRODUCTION

Air pollution presents a major public health threat to India, affecting more than three quarters of the country's population. In the current project, GEOHealth Health Effects of Selected Environmental Exposomes Across the Life CourSe-India, we aim to study the effect of environmental exposomes-fine particulate matter (PM2.5), nitrogen dioxide (NO2), ozone (O3) and extremes of temperature-on multiple health outcomes using a modified life course approach. The associated training grant aims to build capacity in India to address the unique environmental health problems.

METHODS AND ANALYSIS

The project aims to (A) Develop exposure assessments in seven cities, namely Delhi, Chennai, Sonipat, Vizag, Pune, Hyderabad and Bikaner, for: (1) A fine-scale spatiotemporal model for multiple pollutants (PM2.5, NO2, O3, temperature); (2) Combined ground monitoring and modelling for major chemical species of ambient PM2.5 at seven cities; and (3) Personal exposure assessment in a subsample from the six cities, except Pune, and (B) Conduct health association studies covering a range of chronic non-communicable diseases and their risk factors leveraging a unique approach using interdigitating cohorts. We have assembled existing pregnancy, child, adolescent, adult and older adult cohorts across India to explore health effects of exposomes using causal analyses. We propose to use Bayesian kernel machine regression to assess the effects of mixtures of all pollutants including species of PM2.5 on health while accounting for potential non-linearities and interactions between exposures. This builds on earlier work that constructed a fine spatiotemporal model for PM2.5 exposure to study health outcomes in two Indian cities.

ETHICS AND DISSEMINATION

Ethical clearance for conduct of the study was obtained from the Institutional Ethics Committee (IEC) of the Centre for Chronic Disease Control, and all the participating institutes and organisations. National-level permission was provided by the Indian Council of Medical Research. The research findings will be disseminated through peer-reviewed publications, policy briefs, print and social media, and communicating with the participating communities and stakeholders. Training of Indian scientists will build the capacity to undertake research on selected adverse environmental exposures on population health in India.

A time-stratified, case-crossover study of heat exposure and perinatal mortality from 16 hospitals in sub-Saharan Africa

Growing evidence suggests that extreme heat events affect both pregnant women and their infants, but few studies are available from sub-Saharan Africa. Using data from 138,015 singleton births in 16 hospitals in Benin, Malawi, Tanzania and Uganda, we investigated the association between extreme heat and early perinatal deaths, including antepartum and intrapartum stillbirths, and deaths within 24 h after birth using a time-stratified case-crossover design. We observed an association between an increase from the 75th to the 99th percentile in mean temperature 1 week (lag 0-6 d) before childbirth and perinatal mortality (odds ratio (OR) = 1.34 (95% confidence interval (CI) 1.01-1.78)). The estimates for stillbirths were similarly positive, but CIs included unity: OR = 1.29 (95% CI 0.95-1.77) for all stillbirths, OR = 1.18 (95% CI 0.71-1.95) for antepartum stillbirths and OR = 1.64 (95% CI 0.74-3.63) for intrapartum stillbirths. The cumulative exposure-response curve suggested that the steepest slopes for heat for intrapartum stillbirths and associations were stronger during the hottest seasons. We conclude that short-term heat exposure may increase mortality risks, particularly for intrapartum stillbirths, raising the importance of improved intrapartum care.

Exposure to Ambient Heat and Risk of Spontaneous Abortion: A Case-Crossover Study

BACKGROUND

Few epidemiologic studies have examined the association of ambient heat with spontaneous abortion, a common and devastating pregnancy outcome.

METHODS

We conducted a case-crossover study nested within Pregnancy Study Online, a preconception cohort study (2013-2022). We included all participants reporting spontaneous abortion (N = 1,524). We defined the case window as the 7 days preceding the event and used time-stratified referent selection to select control windows matched on calendar month and day of week. Within each 7-day case and control window, we measured the mean, maximum, and minimum of daily maximum outdoor air temperatures. We fit splines to examine nonlinear relationships across the entire year and conditional logistic regression to estimate odds ratios (ORs) and 95% confidence interval (CI) of spontaneous abortion with increases in temperature during the warm season (May-September) and decreases during the cool season (November-March).

RESULTS

We found evidence of a U-shaped association between outdoor air temperature and spontaneous abortion risk based on year-round data. When restricting to warm season events (n = 657), the OR for a 10-percentile increase in the mean of lag 0-6 daily maximum temperatures was 1.1 (95% CI: 0.96, 1.2) and, for the maximum, 1.1 (95% CI: 0.99, 1.2). The OR associated with any extreme heat days (>95th county-specific percentile) in the preceding week was 1.2 (95% CI: 0.95, 1.5). Among cool season events (n = 615), there was no appreciable association between lower temperatures and spontaneous abortion risk.

CONCLUSION

Our study provides evidence of an association between high outdoor temperatures and the incidence of spontaneous abortion.

Advocating for planetary health is an essential part of advocating for children's health

Burning of fossil fuels along with deforestation and ecological disruption have led to the warming of the Earth and climate change. Children are especially vulnerable to adverse health effects of climate change associated changes in the air, soil, and water as their organs are still developing, have a faster breathing rate, higher per pound ingested and inhaled exposures, and greater relative body surface area. To protect this vulnerable population, health care professionals need to play a leading role. In 2015, the American Academy of Pediatrics (AAP) updated their original 2007 Global Climate Change and Children's Health policy statement (again updated in 2024) stating that, "failure to take prompt, substantive action would be an act of injustice to all children." Health care professionals need to educate themselves and their patients of the health risks posed by climate change and incorporate climate change counseling into their practice. They also need to go beyond the framework of the healthcare system and work collaboratively with communities, corporations, and governments to advocate for policies and solutions to mitigate and adapt to climate change. The health and wellbeing of future generations rests upon the actions we take today. IMPACT: Summarizes the adverse effects of increased anthropogenic activity and burning of fossil fuels on planetary and human health Details the increased vulnerability of children to environmental assaults and their long-term effects Provides guidance and resources to health care professionals to empower them to act as advocates for systemic and structural changes that protect children's health.