Employment, working conditions, and preterm birth: results from the Europop case-control survey

Short-term ambient temperature variations and incidence of preterm birth: A systematic review and meta-analysis

This study aimed to determine the short-term effects of ambient temperature variations exposures on the incidence of preterm birth (PTB) for each single lag day (lag0 to lag6) and cumulative lag days (lag0-1 to lag0-6) up to a week before birth. To find relevant publications, online databases, including Web of Science, PubMed, and Scopus were searched with appropriate keywords and Mesh terms from their inception to October 25, 2023. Overall, the number of 39 observational studies with 12.5 million pregnant women and 700.000 cases of PTB met our eligibility criteria. The associations of temperature variations with the incidence of PTB were investigated with two different meta-analyses, including the percentile meta-analysis (comparing different percentiles (P1 to P99) with a referent percentile (P50)), and the linear meta-analysis (per 5 °C increment of the temperature levels). For the percentile meta-analysis, we observed both extreme cold (P1, only lag 0) and heat (P95 and P99 with the highest risk at lag1 and lag0-6) exposures can be significantly associated with a higher risk of PTB. The pooled RR (95 % CI) per 5 °C increase in the temperature levels at lag0-6 was estimated as 1.038 (1.018, 1.058) for the overall analysis. Subgroup analysis based on the season shows a significant association in the warm season (RR = 1.082 and 95 % CI = 1.036, 1.128) at all lag days but not the cold season. For the single lag day, we observed the risk of PTB is the highest at lag1 and decreased with moving to lag6. In sum, we suppose there is a nearly V-shape non-linear association between air temperature levels and the incidence of PTB with the linear relationship for each unit increase (also decrease) in the temperature levels above (also below) moderate temperature limits. Future studies should investigate possible association of occupational heat and cold exposure during pregnancy on the incidence of adverse birth outcomes such as PTB.

Maternal Occupational Risk Factors and Preterm Birth: A Systematic Review and Meta-Analysis

Objective: This systematic review and meta-analysis aimed to summarize the evidence on the relationship between physical occupational risks (high physical workload, long working hours, shift work, whole-body vibrations, prolonged standing, and heavy lifting) and preterm birth. Methods: A systematic review and meta-analysis was conducted across six databases to investigate the relationship between physical occupational risks and preterm birth. Result: A comprehensive analysis of 37 studies with varying sample sizes found moderate evidence of positive associations between high physical workload, long working hours, shift work, whole-body vibration, and preterm birth. Meta-analysis showed a 44% higher risk (OR 1.44, 95% CI 1.25-1.66) for preterm birth with long working hours and a 63% higher risk (OR 1.63, 95% CI 1.03-2.58) with shift work. Conclusion: Pregnant women in physically demanding jobs, those working long hours or on shifts, and those exposed to whole-body vibration have an increased risk of preterm birth. Employers should establish supportive workplaces, policymakers implement protective measures, healthcare providers conduct screenings, and pregnant women must stay informed and mitigate these job-related risks. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], Identifier [CRD42022357045].

Difference in risk of preterm and small-for-gestational-age birth depending on maternal occupations in Japan

OBJECTIVES

In this study, an association between the mother's occupations with preterm and small-for-gestational-age (SGA) births was investigated using national data in Japan, and individual-level birth data from the Report of Vital Statistics: Occupational and Industrial Aspects in the 2015 fiscal year were used. Preterm and SGA birth rates were calculated for each of infant characteristics, and relative risk of each type of maternal occupations (categorized into 12 types) for the outcomes was estimated using a log binomial regression model.

RESULTS

Data of 997,600 singleton births were analyzed. Among maternal occupations, preterm birth rate was highest among carrying, cleaning, packaging, and related workers (5.65%) and lowest among security workers (4.24%). SGA birth rate was highest among manufacturing process workers (5.91%) and lowest among security workers (4.00%). We found significantly elevated risks for preterm birth among manufacturing process workers compared with unemployed mothers, and significantly elevated risks for SGA birth compared with unemployed mothers were observed among sales workers, service workers, and manufacturing process workers. In contrast, security workers had a significantly decreased risk for SGA birth compared with unemployed mothers.

Does the father's job matter? Parental occupation and preterm birth in Korea

OBJECTIVES

Limited evidence is available regarding the impact of paternal occupation and its combined effect with maternal occupation on preterm birth. Therefore, we assessed the association of maternal and paternal occupations with preterm birth.

METHODS

We used the national birth data of Korea between 2010 and 2020. Parental occupations were divided into 5 categories: (1) managers; (2) professionals, technicians, and related workers; (3) clerks and support workers; (4) service and sales workers; and (5) manual workers. A multinomial logistic regression model was used to calculate the adjusted odds ratios (aORs) of extremely, very, and moderate-to-late preterm births per occupational category considering individual risk factors.

RESULTS

For the 4,004,976 singleton births, 40.2% of mothers and 95.5% of fathers were employed. Compared to non-employment, employment was associated with a lower risk of preterm birth. Among employed mothers, service and sales occupations were associated with a higher risk of preterm birth than managerial occupations (aOR, 1.06; 95% confidence interval [CI], 1.01 to 1.10 for moderate-to-late preterm births). The father's manual occupation was associated with a higher risk of preterm birth (aOR, 1.09; 95% CI, 1.05 to 1.13 for moderate-to-late preterm) than managerial occupations. When both parents had high-risk occupations, the risk of preterm birth was higher than in cases where only the mother or neither of the parents had a high-risk occupation.

CONCLUSIONS

Paternal occupation was associated with preterm birth regardless of maternal employment and occupation and modified the effect of maternal occupation. Detailed occupational environment data are needed to identify the paternal exposures that increase the risk.

Women's occupational status during pregnancy and preventive behaviour and health outcomes between 1998 and 2016 in France

BACKGROUND

Despite an improvement in preventive care and perinatal health in previous decades, social inequalities persist, particularly to the disadvantage of isolated or unemployed women. The objective was to analyse the evolution between 1998 and 2016 of the association between women's occupational status and perinatal outcomes.

METHODS

Data came from four national surveys performed in 1998, 2003, 2010 and 2016. Occupational status was defined by maternal employment status and type of occupation during pregnancy. Preventive behaviours (initiation of antenatal care, antenatal classes, breast feeding) and health outcomes (hospitalization, preterm birth, birth weight below the 10th percentile) were analysed by occupational status adjusted for other maternal characteristics, for each study year.

RESULTS

The studied sample included 12,497 women in 1998, 13,290 in 2003, 13,209 in 2010 and 11,179 in 2016. The proportion of employed women increased from 66% to 75% between 1998 and 2016, and that of housewives decreased from 22% to 12%. The proportion of preterm births globally increased between 1998 and 2016, especially for housewives. The proportion of low birthweight for gestational age (LBWGA) remained similar over the years. From 1998 to 2016, the differences between occupational groups persisted for preterm births and LBWGA.

CONCLUSIONS

Occupational groups exhibited strong social differences in preventive care over the entire study period and persisted in the recent data. As a major social indicator, women's occupational status during pregnancy has to be considered as a risk factor of poor preventive behaviour and unfavourable perinatal outcomes.

Pregnancy, obstetrical and neonatal outcomes in women exposed to physician-related occupational hazards: a scoping review

OBJECTIVE

Evidence is needed to guide organisational decision making about workplace accommodations for pregnant physicians. Our objective was to characterise the strengths and limitations of current research examining the association between physician-related occupational hazards with pregnancy, obstetrical and neonatal outcomes.

DESIGN

Scoping review.

DATA SOURCES

MEDLINE/PubMed, EMBASE, CINAHL/ EBSCO, SciVerse Scopus and Web of Science/Knowledge were searched from inception to 2 April 2020. A grey literature search was performed on 5 April 2020. The references of all included articles were hand searched for additional citations.

ELIGIBILITY CRITERIA

English language citations that studied employed pregnant people and any 'physician-related occupational hazards', meaning any relevant physical, infectious, chemical or psychological hazard, were included. Outcomes included any pregnancy, obstetrical or neonatal complication.

DATA EXTRACTION AND SYNTHESIS

Physician-related occupational hazards included physician work, healthcare work, long work hours, 'demanding' work, disordered sleep, night shifts and exposure to radiation, chemotherapy, anaesthetic gases or infectious disease. Data were extracted independently in duplicate and reconciled through discussion.

RESULTS

Of the 316 included citations, 189 were original research studies. Most were retrospective, observational and included women in any occupation rather than healthcare workers. Methods for exposure and outcome ascertainment varied across studies and most studies had a high risk of bias in data ascertainment. Most exposures and outcomes were defined categorically and results from different studies could not be combined in a meta-analysis due to heterogeneity in how these categories were defined. Overall, some data suggested that healthcare workers may have an increased risk of miscarriage compared with other employed women. Long work hours may be associated with miscarriage and preterm birth.

CONCLUSIONS

There are important limitations in the current evidence examining physician-related occupational hazards and adverse pregnancy, obstetrical and neonatal outcomes. It is not clear how the medical workplace should be accommodated to improve outcomes for pregnant physicians. High-quality studies are needed and likely feasible.

Preterm Birth: An Overview

Birth order has a significant impact on perinatal and long-term outcomes. Preterm birth rates, ranging from 5% to 18%, are regrettably still high in industrialized and developing countries, making them the main contributor to infant mortality and morbidity. Infection, cervical pathology, uterine overdistension, progesterone deficiency, stress on the mother and fetus, allograft reaction, allergic phenomena, and likely more unknown factors are just a few of the causes of preterm birth syndrome. These several causes may improperly stimulate the usual pathway between the decidua and the fetal membranes, resulting in cervical ripening, membrane rupture, and uterine contractility. Some of the mechanisms underpinning these actions include receptors, chemokines, and inflammatory cytokines. For early identification, treatment, and avoidance of negative consequences, it is essential to understand the cellular and metabolic mechanisms that cause preterm labor. Clinicians and researchers are crucial to improving our knowledge of the biochemistry of preterm delivery, identifying risk factors, and creating treatments for this challenging condition. Intrauterine growth restriction and pre-eclampsia or eclampsia are frequent causes of suspected preterm births. "Spontaneous preterm births" occur after preterm labor that develops without warning with an early membrane rupture. It is thought that the condition that may cause these births may have several causes, such as uterine overdistension, vascular disease, infection, or inflammation. Unplanned preterm births have several reasons, including the black race, periodontal disease, low mother body mass index (BMI), and previous preterm births. A short cervical length and a high cervical-vaginal fetal fibronectin concentration are the two best signs of premature birth.

Influence of sociodemographic factors in birth seasonality in Spain

OBJECTIVES

The goal of the present research is to establish for the first time a hierarchy of sociodemographic factors according to their importance influencing birth seasonality.

METHODS

We used Vital Statistics data on all births registered in Spain in the period 2016-2019. Differences in the degree of seasonality between sociodemographic groups (defined by maternal age, maternal marital status, maternal education, birth order, maternal job qualification, maternal employment status, maternal location population size, and maternal country of birth) were first examined with descriptive techniques. Secondly, analysis through alternative Data Mining techniques determined the association between sociodemographic factors and birth seasonality and the factors importance rank.

RESULTS

Those factors related to maternal labor status (employment status, job qualification, and education) were found to be the most relevant influencing birth seasonality. It was found that the overall seasonal pattern in Spain was driven by lower skilled employed mothers, in contrast with not employed or high skilled employed mothers, who showed a different or weaker seasonality. Finally, we found that a change in the rhythm pattern has taken place in the last decades in Spain.

CONCLUSIONS

Birth seasonality is to a large extent related to maternal employment status. Employed mothers, normally more affected by the seasonality of work calendar than the unemployed, show higher conception rates structured around holidays. This may indicate that the observed change of seasonal pattern in Spain in the last decades, as in other European countries, may be specifically driven by the progressive higher participation of women in labor market.

A survey of Australian and New Zealand medical parents' experiences of infertility, pregnancy, and parenthood

Objective

To describe the incidence of infertility, pregnancy complications, and breastfeeding practices among Australian and New Zealand doctors and identify factors associated with increased pregnancy complication rates.

Methods

A survey of ANZ doctors using an online questionnaire during November 2021.

Results

One thousand ninety-nine completed responses were received. The median age of female doctors at the time of their first child was 32.4. Fertility testing was undertaken by 37%, with 27% having in vitro fertilization. More than 60% of respondents delayed family planning due to work. Pregnancy loss occurred in 36% of respondents, and 50% suffered a pregnancy complication. There were significant differences between specialists, with surgeons working longer hours before and after pregnancy, but having greater access to maternity leave than general practitioners.

Conclusion

Female doctors delay starting and completing their family due to work-related demands and structural biases in career progression, which may result in higher infertility and pregnancy complication rates.

Association between Maternal Factors, Preterm Birth, and Low Birth Weight of Chilean Singletons

There has been an increase in preterm (PT) births in Western countries in recent years, which is associated with low-birthweight (LBW) children. The aim of this study was to determine the association between maternal factors and PT and LBW Chilean newborns. Methods: This was an analytical cross-sectional study of a national sample of 903,847 newborns and their mothers. The newborn gestational age, birth weight, maternal age, marital status, education, employment situation, and residence were analyzed. A multivariate logistic regression model was applied (α = 0.05) (STATA v.15). The prevalence was 6.8% and 5.0% for PT and LBW, respectively. The probability of the newborns being PT and LBW was 1.18 and 1.22 times if their mothers had <12 years of education and 1.38 and 1.29 times if the mothers were ≥35 years old, respectively. Mothers with <12 years education and ≥35 years were risk factors for PT and LBW newborns. Maternal educational attainment was a protective factor for the Chilean newborns, and a maternal age ≥35 years was a risk factor for PT and LBW.

Lack of Workplace Support for Obstetric Health Concerns is Associated with Major Pregnancy Complications: A National Study of US Female Surgeons

OBJECTIVE

We sought to assess whether lack of workplace support for clinical work reductions during pregnancy was associated with major pregnancy complications.

SUMMARY BACKGROUND DATA

Surgeons are at high risk of major pregnancy complications. Although rigorous operative schedules pose increased risk, few reduce their clinical duties during pregnancy.

METHODS

An electronic survey was distributed to U.S. surgeons who had at least one live birth. Lack of workplace support was defined as: (1) desiring but feeling unable to reduce clinical duties during pregnancy due to failure of the workplace/training program to accommodate and/or concerns about financial penalties, burden on colleagues, requirement to make up missed call, being perceived as weak; (2) disagreeing colleagues and/or leadership were supportive of obstetrician-prescribed bedrest. Multivariate logistic regression determined the association between lack of workplace support and major pregnancy complications.

RESULTS

Of 671 surgeons, 437 (65.13%) reported lack of workplace support during pregnancy and 302 (45.01%) experienced major pregnancy complications. Surgeons without workplace support were at higher risk of major pregnancy complications than those who had workplace support (OR 2.44; 95%CI 1.58-3.75). 110/671 (16.39%) surgeons were prescribed bedrest, of whom 38 (34.55%) disagreed that colleagues and/or leadership were supportive. Of the remaining surgeons, 417/560 (74.5%) desired work reductions but were deterred by lack of workplace support.

CONCLUSIONS

Lack of workplace support for reduction in clinical duties is associated with adverse obstetric outcomes for surgeons. This is a modifiable workplace obstacle that deters surgeons from acting to optimize their infant's and their own health. To ensure the health of expectant surgeons, departmental policies should support reduction of clinical workload in an equitable manner without creating financial penalties, requiring payback for missed call duties, or overburdening colleagues.

Ability of municipality-level deprivation indices to capture social inequalities in perinatal health in France: A nationwide study using preterm birth and small for gestational age to illustrate their relevance

BACKGROUND

Evidence-based policy-making to reduce perinatal health inequalities requires an accurate measure of social disparities. We aimed to evaluate the relevance of two municipality-level deprivation indices (DIs), the French-Deprivation-Index (FDep) and the French-European-Deprivation-Index (FEDI) in perinatal health through two key perinatal outcomes: preterm birth (PTB) and small-for-gestational-age (SGA).

METHODS

We used two data sources: The French National Perinatal Surveys (NPS) and the French national health data system (SNDS). Using the former, we compared the gradients of the associations between individual socioeconomic characteristics (educational level and income) and "PTB and SGA" and associations between municipality-level DIs (Q1:least deprived; Q5:most deprived) and "PTB and SGA". Using the SNDS, we then studied the association between each component of the two DIs (census data, 2015) and "PTB and SGA". Adjusted odds ratios (aOR) were estimated using multilevel logistic regression with random intercept at the municipality level.

RESULTS

In the NPS (N = 26,238), PTB and SGA were associated with two individual socioeconomic characteristics: maternal educational level (≤ lower secondary school vs. ≥ Bachelor's degree or equivalent, PTB: aOR = 1.43 [1.22-1.68], SGA: (1.31 [1.61-1.49]) and household income (< 1000 € vs. ≥ 3000 €, PTB: 1.55 [1.25-1.92], SGA: 1.69 [1.45-1.98]). For both FDep and FEDI, PTB and SGA were more frequent in deprived municipalities (Q5: 7.8% vs. Q1: 6.3% and 9.0% vs. 5.9% for PTB, respectively, and 12.0% vs. 10.3% and 11.9% vs. 10.2% for SGA, respectively). However, after adjustment, neither FDep nor FEDI showed a significant gradient with PTB or SGA. In the SNDS (N = 726,497), no FDep component, and only three FEDI components were significantly associated (specifically, the % of the population with ≤ lower secondary level of education with both outcomes (PTB: 1.5 [1.15-1.96]); SGA: 1.25 [1.03-1.51]), the % of overcrowded (i.e., > 1 person per room) houses (1.63 [1.15-2.32]) with PTB only, and unskilled farm workers with SGA only (1.52 [1.29-1.79]).

CONCLUSION

Some components of FDep and FEDI were less relevant than others for capturing ecological inequalities in PTB and SGA. Results varied for each DI and perinatal outcome studied. These findings highlight the importance of testing DI relevance prior to examining perinatal health inequalities, and suggest the need to develop DIs that are suitable for pregnant women. .

Unsupervised Learning Applied to the Stratification of Preterm Birth Risk in Brazil with Socioeconomic Data

Preterm birth (PTB) is a phenomenon that brings risks and challenges for the survival of the newborn child. Despite many advances in research, not all the causes of PTB are already clear. It is understood that PTB risk is multi-factorial and can also be associated with socioeconomic factors. Thereby, this article seeks to use unsupervised learning techniques to stratify PTB risk in Brazil using only socioeconomic data. Through the use of datasets made publicly available by the Federal Government of Brazil, a new dataset was generated with municipality-level socioeconomic data and a PTB occurrence rate. This dataset was processed using various unsupervised learning techniques, such as k-means, principal component analysis (PCA), and density-based spatial clustering of applications with noise (DBSCAN). After validation, four clusters with high levels of PTB occurrence were discovered, as well as three with low levels. The clusters with high PTB were comprised mostly of municipalities with lower levels of education, worse quality of public services-such as basic sanitation and garbage collection-and a less white population. The regional distribution of the clusters was also observed, with clusters of high PTB located mostly in the North and Northeast regions of Brazil. The results indicate a positive influence of the quality of life and the offer of public services on the reduction in PTB risk.

A Critical Review on the Complex Interplay between Social Determinants of Health and Maternal and Infant Mortality

Background: U.S. maternal and infant mortality rates constitute an important public health problem, because these rates surpass those in developed countries and are characterized by stark disparities for racial/ethnic minorities, rural residents, and individuals with less privileged socioeconomic status due to social determinants of health (SDoH). Methods: A critical review of the maternal and infant mortality literature was performed to determine multilevel SDoH factors leading to mortality disparities with a life course lens. Results: Black mothers and infants fared the worst in terms of mortality rates, likely due to the accumulation of SDoH experienced as a result of structural racism across the life course. Upstream SDoH are important contributors to disparities in maternal and infant mortality. More research is needed on the effectiveness of continuous quality improvement initiatives for the maternal–infant dyad, and expanding programs such as paid maternity leave, quality, stable and affordable housing, and social safety-nets (Medicaid, CHIP, WIC), in reducing maternal and infant mortality. Finally, it is important to address research gaps in individual, interpersonal, community, and societal factors, because they affect maternal and infant mortality and related disparities. Conclusion: Key SDoH at multiple levels affect maternal and infant health. These SDoH shape and perpetuate disparities across the lifespan and are implicated in maternal and infant mortality disparities.

Preterm birth and its associated factors among reproductive aged women in sub-Saharan Africa: evidence from the recent demographic and health surveys of sub-Sharan African countries

BACKGROUND

Globally, preterm birth is the leading cause of neonatal and under-five children mortality. Sub-Saharan African (SSA) accounts for the majority of preterm birth and death following its complications. Despite this, there is limited evidence about the pooled prevalence and associated factors of preterm birth at SSA level using nation-wide representative large dataset. Therefore, this study aimed to determine the pooled prevalence and associated factors of preterm birth among reproductive aged women.

METHODS

The recent Demographic and Health Surveys (DHSs) data of 36 SSA countries were used. We included a total weighted sample of 172,774 reproductive-aged women who were giving birth within five years preceding the most recent survey of SSA countries were included in the analysis. We used a multilevel logistic regression model to identify the associated factors of preterm birth in SSA. We considered a statistical significance at a p-value less than 0.05.

RESULTS

In this study, 5.33% (95% CI: 5.23, 5.44%) of respondents in SSA had delivered preterm baby. Being form eastern Africa, southern Africa, rural area, being educated, substance use, having multiple pregnancy, currently working history, having history of terminated pregnancy, and previous cesarean section delivery, primi-parity, and short birth interval were associated with higher odds of preterm birth among reproductive aged women. However, having better wealth index, being married, wanted pregnancy, and having four or more antenatal care visit were associated with lower odds for a preterm birth among reproductive aged women.

CONCLUSION

The prevalence of preterm birth among reproductive-aged women remains a major public health problem in SSA. Preterm birth was affected by various socio-economic and obstetrical factors. Therefore, it is better to consider the high-risk groups during intervention to prevent the short-term and long-term consequences of preterm birth.

Incidence of Infertility and Pregnancy Complications in US Female Surgeons

Importance

While surgeons often delay pregnancy and childbearing because of training and establishing early careers, little is known about risks of infertility and pregnancy complications among female surgeons.

Objective

To describe the incidence of infertility and pregnancy complications among female surgeons in the US and to identify workplace factors associated with increased risk compared with a sociodemographically similar nonsurgeon population.

Design, Setting, and Participants

This self-administered survey questionnaire was electronically distributed and collected from November 2020 to January 2021 through multiple surgical societies in the US and social media among male and female attending and resident surgeons with children. Nonchildbearing surgeons were asked to answer questions regarding the pregnancies of their nonsurgeon partners as applicable.

Exposures

Surgical profession; work, operative, and overnight call schedules.

Main Outcomes and Measures

Descriptive data on pregnancy loss were collected for female surgeons. Use of assisted reproductive technology was compared between male and female surgeons. Pregnancy and neonatal complications were compared between female surgeons and female nonsurgeon partners of surgeons.

Results

A total of 850 surgeons (692 women and 158 men) were included in this survey study. Female surgeons with female partners were excluded because of lack of clarity about who carried the pregnancy. Because the included nonchildbearing population was therefore made up of male individuals with female partners, this group is referred to throughout the study as male surgeons. The median (IQR) age was 40 (36-45) years. Of 692 female surgeons surveyed, 290 (42.0%) had a pregnancy loss, more than twice the rate of the general population. Compared with male surgeons, female surgeons had fewer children (mean [SD], 1.8 [0.8] vs 2.3 [1.1]; P < .001), were more likely to delay having children because of surgical training (450 of 692 [65.0%] vs 69 of 158 [43.7%]; P < .001), and were more likely to use assisted reproductive technology (172 of 692 [24.9%] vs 27 of 158 [17.1%]; P = .04). Compared with female nonsurgeon partners, female surgeons were more likely to have major pregnancy complications (311 of 692 [48.3%] vs 43 of 158 [27.2%]; P < .001), which was significant after controlling for age, work hours, in vitro fertilization use, and multiple gestation (odds ratio [OR], 1.72; 95% CI, 1.11-2.66). Female surgeons operating 12 or more hours per week during the last trimester of pregnancy were at higher risk of major pregnancy complications compared with those operating less than 12 hours per week (OR, 1.57; 95% CI, 1.08-2.26). Compared with female nonsurgeon partners, female surgeons were more likely to have musculoskeletal disorders (255 of 692 [36.9%] vs 29 of 158 [18.4%]; P < .001), nonelective cesarean delivery (170 of 692 [25.5%] vs 24 of 158 [15.3%]; P = .01), and postpartum depression (77 of 692 [11.1%] vs 9 of 158 [5.7%]; P = .04).

Conclusions and Relevance

This national survey study highlighted increased medical risks of infertility and pregnancy complications among female surgeons. With an increasing percentage of women representing the surgical workforce, changing surgical culture to support pregnancy is paramount to reducing the risk of major pregnancy complications, use of fertility interventions, or involuntary childlessness because of delayed attempts at childbearing.

First trimester employment, working conditions and preterm birth: a prospective population-based cohort study

Objectives

To explore the association between working conditions during first trimester and total preterm birth (PTB), and subtypes: spontaneous PTB and iatrogenic PTB, additionally to explore the role of hypertension.

Methods

Pregnant women from the Amsterdam Born Children and their Development study, filled out a questionnaire between January 2003 and March 2004, two weeks after first prenatal screening (singleton liveborn, n=7561). Working conditions were working hours/week, standing/walking hours/week, physical work load and job strain.

Results

Prolonged standing/walking during first trimester was associated with an increased risk for total PTB (OR=1.5; 95% CI 1.0–2.3, after adjustments). Other working conditions were not related to total PTB. The separation into spontaneous and iatrogenic PTB revealed that standing/walking was associated with iatrogenic PTB only (OR=2.09; 95% CI 1.00–4.97). The highest risk was found for the combination of a long workweek with high physical work load (OR=3.42; 95% CI 1.04–8.21). Hypertension did not mediate these associations; however, stratified analysis revealed that high physical work load was only related to iatrogenic PTB when pregnancy-induced hypertension was present (OR=6.44; 95% CI 1.21–29.76).

Conclusion

This study provides evidence that high physically demanding work is associated with an increased risk for iatrogenic PTB and not with spontaneous PTB. Pregnancy-induced hypertension may play a role: when present, high physical work load leads to a more severe outcome.

Understanding the multidimensional trajectory of psychosocial maternal risk factors causing preterm birth: A systematic review

OBJECTIVES

Among all known risk factors of preterm birth, psychosocial factors form an intricate collection, which includes a multidimensional spectrum of interrelated mediating mechanisms. The understanding of these interconnected mechanisms is vital for designing targeted interventions to reduce preterm births. The objective of this systematic review was to investigate potential psychosocial maternal factors and their interactions to cause preterm birth.

METHODS

PubMed, CINAHL, Scopus, Medline, and Cochrane Database of Systematic Reviews were searched for U.S.-based English language studies published between 1989 and 2019. Titles, abstracts, and full-texts were screened to determine eligibility for inclusion. Data were extracted from eligible studies using a customized data collection form. The National Institutes of Health assessment tool was utilized for quality assessment.

RESULTS

Among the 76 full texts that were reviewed, 9 records met the eligibility criteria, and were included in the final review. The included publications addressed psychosocial factors including racial disparity, lifetime racism, neighborhood disadvantage, lack of partner support, childhood maltreatment and life-course variations, including homelessness and marital status. Antenatal stress was identified as a common mechanism through which psychosocial mediators may act to cause preterm birth.

CONCLUSIONS

This review highlights the need for controlling potential risk factors of maternal stress by improving prenatal care, providing proper housing, and establishing conducive social environments for pregnant women. The review also suggests the importance of maternal psychological counselling and extensive maternal health monitoring among minority groups during the pregnancy period.

Controversies in the prevention of spontaneous preterm birth in asymptomatic women: an evidence summary and expert opinion

Preterm birth prevention is multifaceted and produces many nuanced questions. This review addresses six important clinical questions about preterm birth prevention as voted for by members of the UK Preterm Clinical Network. The questions cover the following areas: preterm birth prevention in 'low-risk' populations; screening for asymptomatic genital tract infection in women at high risk of preterm birth; cervical length screening with cerclage or vaginal pessary in situ; cervical shortening whilst using progesterone; use of vaginal progesterone in combination with cervical cerclage; and optimal advice about intercourse for women at high risk of preterm birth.

Occupational lifting and adverse pregnancy outcome: a systematic review and meta-analysis

This systematic review was conducted to help clarify the effect of lifting at work on pregnancy outcome, by focusing on specific exposure categories. A search in Medline and Embase identified 51 articles reporting association of spontaneous abortion (SA), preterm delivery (PTD) or small-for-gestational-age (SGA) infant with exposure to occupational lifting. A global validity score was assigned to each study and six potential sources of bias were considered in sensitivity analyses. For each exposure–outcome combination, a summary risk estimate (RE) was obtained from all studies and from a subset of studies with high validity score, this latter summary RE was selected as a final result. Statistical heterogeneity was measured with I2 and Q tests and the possibility of a publication bias was also assessed. For each meta-analysis, the strength of evidence was established from explicit criteria. Heavy (or ≥10 kg) loads often (or ≥10x/day) lifted were associated with increased risks of SA (summary RE=1.31, 95% CI 1.17 to 1.47) and PTD (summary RE=1.24, 95% CI 1.07 to 1.43), with good strength of evidence. No association was identified with SGA, nor with lower exposure levels and SA or PTD. These results are reassuring for lower levels of exposure; however, observed associations can guide health professionals’ recommendations aimed at the prevention of SA and PTD for pregnant women who frequently lift (or ≥10x/day) heavy (or ≥10 kg) loads at work.

Résumé

The impact of occupational activities during pregnancy on pregnancy outcomes: a systematic review and metaanalysis

OBJECTIVE

Data: An increasing number of studies suggest that exposure to physically demanding work during pregnancy could be associated with increased risks of adverse pregnancy outcomes, but the results remain conflicted and inconclusive. The purpose of this study was to examine the influence of occupational activities during pregnancy on maternal and fetal health outcomes.

STUDY

Studies of all designs (except case studies and reviews) that contained information on the relevant population (women who engaged in paid work during pregnancy), occupational exposures (heavy lifting, prolonged standing, prolonged walking, prolonged bending, and heavy physical workload), comparator (no exposure to the listed physical work demands), and outcomes (preterm birth, low birthweight, small for gestational age, miscarriage, gestational hypertension, preeclampsia, gestational diabetes mellitus, stillbirth, and intrauterine growth restriction) were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

Five electronic databases and 3 gray literature sources were searched up to March 15, 2019.

RESULTS

Eighty observational studies (N=853,149) were included. Low-to-very low certainty evidence revealed that lifting objects ≥11 kg was associated with an increased odds ratio of miscarriage (odds ratio, 1.31; 95% confidence interval, 1.08-1.58; I²=79%), and preeclampsia (odds ratio, 1.35; 95% confidence interval, 1.07-1.71; I²=0%). Lifting objects for a combined weight of ≥100 kg per day was associated with an increased odds of preterm delivery (odds ratio, 1.31; 95% confidence interval, 1.11-1.56; I²=0%) and having a low birthweight neonate (odds ratio, 2.08; 95% confidence interval, 1.06-4.11; I²=73%). Prolonged standing was associated with increased odds of preterm delivery (odds ratio, 1.11; 95% confidence interval, 1.02-1.22; I²=30%) and having a small-for-gestational-age neonate (odds ratio, 1.17; 95% confidence interval, 1.01-1.35; I²=41%). A heavy physical workload was associated with increased odds of preterm delivery (odds ratio, 1.23; 95% confidence interval, 1.07-1.41; I²=32%) and having a low birthweight neonate (odds ratio, 1.79; 95% confidence interval, 1.11-2.87; I²=87%). All other associations were not statistically significant. Dose-response analysis showed women stand for >2.5 hours per day (vs no standing) had a 10% increase in the odds of having a preterm delivery.

CONCLUSION

Physically demanding work during pregnancy is associated with an increased risk of adverse pregnancy outcomes.

Pregnant Women's Experiences of Social Roles: An Ethnophenomenological Study

Background:

The role of women and men is changing across the world, and women, including pregnant women, are adopting newer roles in traditional societies like Iran. This study aimed to explore the meaning of pregnant women's experiences regarding their social roles in the sociocultural context of Iran.

Materials and Methods:

This study was carried out using an ethnophenomenological approach. Participants included 16 pregnant women who attended health centers, hospitals, and private obstetric clinics in Mashhad, Iran, between 2016 and 2017 and were selected based on purposive sampling. In-depth semistructured interviews, vignette interviews, participant observations, and field notes were used to collect data. To analyze data, six-step van Manen's (1997) descriptive-interpretive phenomenological approach was used.

Results:

Through data analysis, the overarching theme of “selection, management, and adjustment of various roles to play social roles” was emerged. This was consisted of four themes: “Mother's perspective regarding out-of-home employment, incompatibility between pregnancy and social roles, mother's management strategies to play different roles, and husband's authority regarding mother's employment.”

Conclusions:

The consequence of reciprocal endeavors of pregnant women along with their husbands as well as their work environment expectations tends to selection, management, and adjustment of feminine roles. Since the employment of pregnant women leads to their more physical and psychological involvement, not only the problems of working women but also the expectations and rules of the workplaces as well as the requests of their husbands should be taken into account.

The impact of occupational shift work and working hours during pregnancy on health outcomes: a systematic review and meta-analysis

BACKGROUD

An increasing number of original studies suggest that exposure to shift work and long working hours during pregnancy could be associated with the risk of adverse pregnancy outcomes, but the results remain conflicting and inconclusive.

OBJECTIVE

To examine the influences of shift work and longer working hours during pregnancy on maternal and fetal health outcomes.

DATA SOURCES

Five electronic databases and 3 gray literature sources were searched up to March 15, 2019.

METHODS OF STUDY SELECTION

Studies of all designs (except case studies and reviews) were included, which contained information on the relevant population (women who engaged in paid work during pregnancy); exposure (rotating shift work [shifts change according to a set schedule], fixed night shift [typical working period is between 11:00 pm and 11:00 am] or longer working hours [>40 hours per week]);comparator (fixed day shift [typical working period is between 8:00 am and 6:00 pm] or standard working hours [≤40 hours per week]); and outcomes (preterm delivery, low birthweight [birthweight <2500 g], small for gestational age, miscarriage, gestational hypertension, preeclampsia, intrauterine growth restriction, stillbirth, and gestational diabetes mellitus).

TABULATION, INTEGRATION, AND RESULTS

From 3305 unique citations, 62 observational studies (196,989 women) were included. "Low" to "very low" certainty evidence from these studies revealed that working rotating shifts was associated with an increased odds of preterm delivery (odds ratio, 1.13; 95% confidence interval, 1.00-1.28, I² = 31%), an infant small for gestational age (odds ratio, 1.18, 95% confidence interval, 1.01-1.38, I² = 0%), preeclampsia (odds ratio, 1.75, 95% confidence interval, 1.01-3.01, I² = 75%), and gestational hypertension (odds ratio, 1.19, 95% confidence interval, 1.10-1.29, I² = 0%), compared to those who worked a fixed day shift. Working fixed night shifts was associated with an increased odds of preterm delivery (odds ratio, 1.21; 95% confidence interval, 1.03-1.42; I² = 36%) and miscarriage (odds ratio, 1.23; 95% confidence interval, 1.03-1.47; I² = 37%). Compared with standard hours, working longer hours was associated with an increased odds of miscarriage (odds ratio, 1.38; 95% confidence interval, 1.08-1.77; I² = 73%), preterm delivery (odds ratio, 1.21; 95% confidence interval, 1.11-1.33; I² = 30%), an infant of low birthweight (odds ratio, 1.43; 95% confidence interval, 1.11-1.84; I² = 0%), or an infant small for gestational age (odds ratio, 1.16, 95% confidence interval, 1.00-1.36, I² = 57%). Dose-response analysis showed that women working more than 55.5 hours (vs 40 hours) per week had a 10% increase in the odds of having a preterm delivery.

CONCLUSION

Pregnant women who work rotating shifts, fixed night shifts, or longer hours have an increased risk of adverse pregnancy outcomes.

Maternal interpregnancy weight change and premature birth: Findings from an English population-based cohort study

Background

The relationship between maternal weight change between pregnancies and premature birth is unclear. This study aimed to investigate whether interpregnancy weight change between first and second, or second and third pregnancy is associated with premature birth.

Methods

Routinely collected data from 2003 to 2018 from one English maternity centre was used to produce two cohorts. The primary cohort (n = 14,961 women) consisted of first and second live-birth pregnancies. The secondary cohort (n = 5,108 women) consisted of second and third live-birth pregnancies. Logistic regression models were used to examine associations between interpregnancy BMI change and premature births adjusted for confounders. Subgroup analyses were carried out, stratifying by initial pregnancy BMI groups and analysing spontaneous and indicated premature births separately.

Results

In the primary cohort, 3.4% (n = 514) of births were premature compared to 4.2% (n = 212) in the secondary cohort, with fewer indicated than spontaneous premature births in both cohorts.

Primary cohort

Weight loss (>3kg/m²) was associated with increased odds of premature birth (adjusted odds ratio (aOR):3.50, 95% CI: 1.78–6.88), and spontaneous premature birth (aOR: 3.34, 95%CI: 1.60–6.98), in women who were normal weight (BMI 18.5-25kg/m²) at first pregnancy. Weight gain >1kg/m² was not associated with premature birth regardless of starting BMI.

Secondary cohort

Losing >3kg/m² was associated with increased odds of premature birth (aOR: 2.01, 95%CI: 1.05–3.87), when analysing the whole sample, but not when restricting the analysis to women who were overweight or obese at second pregnancy.

Conclusions

Normal-weight women who lose significant weight (>3kg/m²) between their first and second live pregnancies have greater odds of premature birth compared to normal-weight women who remain weight stable in the interpregnancy period. There was no evidence of association between weight change in women who were overweight or obese at the start of their first pregnancy and premature birth.

Non-medical determinants of perinatal health: protocol for a systematic review with meta-analysis

INTRODUCTION

Research focusing on the associations between non-medical determinants and unfavourable perinatal health outcomes is increasing. Despite increasing knowledge on this theme, it still remains unclear to what extent social, environmental and lifestyle factors contribute to these unfavourable outcomes. Therefore, we aim to provide a systematic review, preferably with meta-analysis, in order to provide insight into the associations between non-medical determinants and perinatal mortality, preterm birth and being small for gestational age (SGA).

METHODS AND ANALYSIS

Observational studies performed in European countries studying the associations between non-medical determinants and unfavourable perinatal health outcomes will be included. Primary outcomes of interest are perinatal mortality, preterm birth and SGA. To retrieve potential eligible articles, a systematic literature search was performed in the following online databases on 5 October 2018: MEDLINE, Embase, Web of Science, Cochrane and Google Scholar. Additionally, a reference list check and citation search will be performed. Data of the included articles will be extracted using a standardised and piloted data extraction form. Risk of bias will be assessed using the Newcastle-Ottawa Scale. The study selection and data extraction process will be performed by two reviewers independently. Disagreements will be resolved through discussion with a third reviewer. The pooled effects will be calculated separately for each association found between one of the outcome measures and the non-medical determinants using a random effects model. Heterogeneity of the studies will be assessed using the I² statistic.

ETHICS AND DISSEMINATION

No ethical approval is necessary for a systematic review with meta-analysis. The findings will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42018056105.

Fermented foods and preterm birth risk from a prospective large cohort study: the Japan Environment and Children's study

Background

The dietary pattern of pregnant women is known to be associated with preterm birth (PTB). We investigated whether PTB was associated with intake of fermented food by using data from the Japan Environment and Children’s Study.

Methods

From a data set of 103,099 pregnancies, 77,667 cases at low risk for PTB were analyzed. The primary outcome measurements were based on PTB. Fermented food (miso soup, yogurt, cheese, and fermented soybeans) consumption was assessed by using a semi-quantitative food frequency questionnaire.

Results

Intake of miso soup, yogurt, and fermented soybeans before pregnancy significantly reduced the risk of early PTB (< 34 weeks). The adjusted odds ratio (OR) for early PTB in women who had miso soup 1–2 days/week, 3–4 days/week, or ≥ 5 days/week were 0.58, 0.69, and 0.62, respectively, compared with those who had miso soup < 1 day/week (95% confidence interval (CI) 0.40–0.85, 0.49–0.98, and 0.44–0.87). The adjusted OR for early PTB in women who ate yogurt ≥ 3 times/week was 0.62 (95% CI, 0.44–0.87) compared to those who ate yogurt < 1 time/week. The adjusted OR for early PTB in women who ate fermented soybeans ≥ 3 times/week was 0.60 (95% CI, 0.43–0.84) compared to those who ate < 1 time/week. However, the incidence of overall PTB and late PTB (34–36 weeks) was not associated with fermented food intake.

Conclusion

PTB low-risk women with a high consumption of miso soup, yogurt, and fermented soybeans before pregnancy have a reduced risk of early PTB.

Electronic supplementary material

The online version of this article (10.1186/s12199-019-0782-z) contains supplementary material, which is available to authorized users.

Full-time exposure to occupational noise during pregnancy was associated with reduced birth weight in a nationwide cohort study of Swedish women

Noise is a common exposure in the occupational work environment. Earlier studies of occupational noise and pregnancy outcome are few and show mixed results. To investigate if objectively assessed exposure to occupational noise during pregnancy is associated with reduced intrauterine growth and/or preterm birth a nationwide cohort study of 857,010 single births was initiated. Individual information on occupation and risk factors was retrieved from prenatal care interviews at pregnancy week 10. Occupational noise was classified into three exposure categories <75, 75-85, >85 dBA by a job exposure matrix. Odds ratios were adjusted for BMI, smoking, parity, education, physically strenuous work and low job control. Exposure to high (>85 dBA) levels of occupational noise throughout the pregnancy (full time workers) was associated with an increased risk of the child being born small for gestational age, OR 1.44 (95% CI 1.01 to 2.03) compared to noise exposure <75 dBA. A similar increase was seen for low birth weight OR 1.36 (95% CI 1.03 to 1.80) for high levels of noise. No clear association was seen for preterm birth. No consistent effects on birth outcome was observed in women who had worked part-time or were on leave of absence >21 days (median). In summary, full-time exposure to high levels of noise during pregnancy was associated with a slightly reduced fetal growth but not with preterm birth. The effect of intermediate occupational noise exposure (75-85 dBA) showed a small, but statistically increased risk for all studied birth outcomes. The study strengthens the evidence that pregnant women should not be long-term exposed to high levels >85 dBA of occupational noise during pregnancy. Intermediate exposure should be studied further.

Traffic noise exposure in relation to adverse birth outcomes and body mass between birth and adolescence

BACKGROUND

There is growing evidence that traffic noise exposure is associated with adiposity among adults but data in children are limited.

OBJECTIVE

This longitudinal study examined whether pre- and postnatal noise exposure is associated with body mass index (BMI) between birth and adolescence or with adverse birth outcomes.

METHODS

The study was conducted using data from the BAMSE birth cohort, which included 4089 children born in Stockholm County, Sweden. Data on BMI from birth to adolescence were collected via questionnaires, clinical examinations and health care records. A national register provided information on birth outcomes. Road traffic noise levels at the most exposed façade were estimated for all residences of the children during follow-up, as well as of their mothers during pregnancy, and time-weighted average exposure was calculated for different time windows. Maternal occupational noise exposure was obtained from a job-exposure-matrix. Logistic- and quantile regression models were used to estimate associations between noise exposure and health outcomes.

RESULTS

We found residential road traffic noise exposure to be associated with increases in BMI from school age to adolescence, but not at earlier ages. In the age groups 8-11 years and 12-16 years the BMI increments were 0.11 kg/m² per 10 dB L_den (95% CI 0.08-0.13) and 0.20 kg/m² per 10 dB L_den (95% CI 0.17-0.22), respectively. Maternal noise exposure during pregnancy was generally unrelated to adverse birth outcomes and BMI from birth to adolescence in the children, however, traffic noise exposure was associated with a decreased risk of preterm birth CONCLUSION: Residential road traffic noise exposure was associated with BMI increases from school age to adolescence, but not at earlier ages. Maternal occupational noise exposure or exposure from road traffic during pregnancy were not consistently related to birth outcomes or BMI from birth to adolescence.

Environmental extreme temperature and daily preterm birth in Sabzevar, Iran: a time-series analysis

Objectives

Most of the studies on the effect of heat stress on preterm birth (PTB) are conducted in temperate climates. Evidence on this effect in hot and arid countries with low and middle income is limited. This paper describes the short-term effect of exposure to the hot and cold environment on a daily number of PTB in Iran.

Methods

The daily number of PTB was obtained from all hospitals of the city. Meteorological and air pollution data from 2011 to 2017 were obtained from a metrological station in the city. A semi-parametric generalized additive model following a quasi-Poisson distribution with the distributed lag non-linear model was selected as a modeling framework for time-series analysis to simultaneously model the short-term and lagged effect of heat stress on PTB in the Sabzevar city.

Results

The minimum and maximum daily temperature were − 11.2 and 45.4 °C respectively. The highest risk estimate at extreme cold temperature was found for apparent temperature (relative risk (RR) 1.83; 95% CI 1.61: 2.09). This pattern was seen for both models. For extreme hot temperatures, the model with mean temperature showed the highest risk increase for both the main model and air pollution adjusted model (RR 1.36; 95% CI 1.25: 1.49). The lowest risk estimate in extremely cold conditions was found in the model with mean temperature. However, for extremely hot temperature conditions, the lowest risk estimate was found for both maximum and apparent temperature.

Conclusion

Obstetricians working in semi-arid areas should be aware of the influence of environmental extreme temperature on the incidence of PTB.

Electronic supplementary material

The online version of this article (10.1186/s12199-018-0760-x) contains supplementary material, which is available to authorized users.

Impact of social capital, harassment of women and girls, and water and sanitation access on premature birth and low infant birth weight in India

BACKGROUND

Globally, preterm birth (PTB) and low infant birth weight (LBW) are leading causes of maternal and child morbidity and mortality. Inadequate water and sanitation access (WASH) are risk factors for PTB and LBW in low-income countries. Physical stress from carrying water and psychosocial stress from addressing sanitation needs in the open may be mechanisms underlying these associations. If so, then living in a community with strong social capital should be able to buffer the adverse effects of WASH on birth outcomes. The objective of this study is to assess the relationships between WASH access and social conditions (including harassment and social capital) on PTB and LBW outcomes among Indian women, and to test whether social conditions modified the association between WASH and birth outcomes.

METHODS AND FINDINGS

This cohort study examined the effect of pre-birth WASH and social conditions on self-reported PTB status and LBW status for 7,926 women who gave birth between 2004/2005 and 2011/2012 Waves of the India Human Development Survey. PTB and LBW occurred in 14.9% and 15.5% of women, respectively. After adjusting for maternal biological and socioeconomic conditions, PTB was associated with sharing a building/compound latrine (Odds Ratio (OR) = 1.55; 95% Confidence Interval (CI) = 1.01, 2.38) versus private latrine access, but suggested an effect in the opposite direction for sharing a community/public latrine (OR = 0.67; CI = 0.45, 1.01). Open defecation, type of drinking water source, minutes per day spent fetching water, and one-way time to a drinking water source were not associated with PTB. LBW was associated with spending more than two hours per day fetching water compared to less than two hours (OR = 1.33; CI = 1.05, 1.70) and suggested an association with open defecation (OR = 1.22; CI = 1.00, 1.48), but was not associated with other types of sanitation, type of drinking water source, or time to a drinking water source. Harassment of women and girls in the community was associated with both PTB (OR = 1.33; CI = 1.09, 1.62) and LBW (OR = 1.26; CI = 1.03, 1.54). The data also showed a possible association of local crime with LBW (OR = 1.30; CI = 1.00, 1.68). Statistically significant (p<0.05) evidence of effect modification was only found for collective efficacy on the association between type of sanitation access and PTB. In addition, stratified analyses identified differences in effect size for walking time to the primary drinking water source and PTB by crime, sanitation access and PTB by harassment, and total hours per day fetching water and LBW by collective efficacy. Limitations of this observational study include risk of bias, inability to confirm causality, reliance on self-reported outcomes, and limited sub-group sample sizes for testing effect modification.

CONCLUSIONS

The relationship between adverse birth outcomes and sanitation access, domestic water fetching, crime, and gender-based harassment suggests physical and psychosocial stress are possible mechanisms by which WASH access affects PTB and LBW among Indian women. Interventions that reduce domestic responsibilities related to water and sanitation and change social norms related to gender-based harassment may reduce rates of PTB and LBW in India.

Maternal socioeconomic factors and the risk of premature birth and low birth weight in Cyprus: a case-control study

Background

Prematurity and low birth weight are significant predictors of perinatal morbidity and mortality and are influenced by the overall health and socioeconomic status of the pregnant mother. Although Cyprus is characterized by the highest prematurity rate in Europe (13.1% in 2014), the relationship between maternal health and socioeconomic characteristics with prematurity and low birth weight has never been investigated. We aimed to investigate the association of maternal demographic, clinical and socioeconomic characteristics with premature delivery and low neonatal birth weight in Cyprus.

Methods

In a case-control design, questionnaire data were collected from 348 women who gave birth prematurely (cases) and 349 women who gave birth at term (controls). Information was obtained on gestation duration and birth weight as well as maternal demographic, socioeconomic and clinical profiles, including parameters such as smoking, body mass index, alcohol consumption, presence of gestational diabetes and mental health factors.

Results

Premature delivery was associated with greater maternal age (OR: 1.12, 95% CI: 1.06–1.18), absence of gestational diabetes (OR: 0.53, 95% CI: 0.30–0.97), long working hours (OR: 3.77, 95% CI: 2.08–6.84) and emotional stress (OR: 8.5, 95% CI: 3.03–23.89). Within the cases group, emotional stress was also associated with lower birth-weight (β: -323.68 (95% CI: -570.36, − 77.00).

Conclusions

The findings of this study demonstrate the positive association of maternal psychological factors, working conditions as well as maternal age with prematurity and low birth weight in Cyprus. Additional, prospective, studies are needed in the country to further investigate these associations and inform public health intervention measures.

Electronic supplementary material

The online version of this article (10.1186/s12978-018-0603-7) contains supplementary material, which is available to authorized users.

Association of Birthweight With Maternal Trajectories of Effort-Reward Imbalance and Demand-Control Across Pregnancy

OBJECTIVES

We assessed longitudinal patterns of effort-reward imbalance (ERI) and demand-control (DC) scores in pregnancy, and their association with newborn birthweight (BW).

METHODS

Sixty-one women were surveyed four times across pregnancy using the ERI and DC questionnaires. Trajectories of change in ERI and DC scores across pregnancy were constructed using growth mixture modeling, and their associations with BW were examined with generalized linear regression.

RESULTS

Declining ERI (diminishing effort with stable/increasing reward) was associated with higher BW (408 g; P = 0.015), and was robust to other work factors. DC trajectory was not significantly associated with BW.

CONCLUSIONS

Declining ERI may reflect improved work psychosocial climate across pregnancy, or a conscious reduction in effort. The ERI model may represent more flexible work characteristics, whereas job control may be less amenable to short-term alteration. Surveys in more diverse pregnant working populations could be recommended.

The Role of Body, Mind, and Environment in Preterm Birth: Mind the Gap

Preterm birth continues to be a problem affecting low-, middle-, and high-income countries, with rates increasing in some areas despite ongoing efforts to reduce the incidence. This emphasizes the need for more effective interventions, particularly if we aim to achieve the broad health targets of the Sustainable Development Goals (SDGs) by 2030. The current focus on medically-oriented interventions such as reducing nonmedically-indicated induction of labor, cesarean birth, and multiple embryo transfers associated with assisted reproductive technologies, as well as the application of cervical cerclage and use of progesterone therapy, though important, are likely only partial solutions to the complex phenomenon of preterm birth. Preterm birth has multiple etiologies. The biologic mechanisms involved in preterm labor and how it may be triggered are not well understood. There is growing evidence to suggest some of these triggers may also be related to stress and environmental conditions. In this review, we focus on evidence concerning psychosocial (mind) and environmental factors (environment) as well as briefly review the evidence related to maternal and fetal factors (body) associated with the risk of preterm birth, with reference to some of the SDGs. We also assess emerging evidence regarding the interaction of the body, mind, and environment in relation to preterm birth, currently a gap in our knowledge, and how these interactions could impact clinical practice. Findings suggest that multidisciplinary expertise and approaches will be needed to develop effective interventions to address the complex etiologies of preterm birth, as opposed to single-risk-factor mitigation. Clinicians and researchers will play key roles in identifying many of these risk factors and shaping interventions that address this complex issue. Addressing the interlinkages between body, mind, and environment through the integration of research and clinical practice is critical to reducing the risk of preterm birth and contributing to the achievement of the SDGs.

Longitudinal Assessment of Effort-Reward Imbalance and Job Strain Across Pregnancy: A Preliminary Study

OBJECTIVES

To assess longitudinal changes in occupational effort-reward imbalance (ERI) and demand-control (DC) scores across pregnancy and examine associations with blood pressure (BP) during pregnancy.

METHODS

A pilot repeated-measures survey was administered four times to a sample of working women across pregnancy using the ERI and DC instruments. Demographic data and blood pressure measurements were collected at each interval. Growth mixture modeling was used to examine trajectories of change in occupational characteristics. Associations with BP were examined using repeated-measures linear regression models.

RESULTS

ERI model components (effort, reward, and overcommitment) all declined across pregnancy while job control remained stable. Increasing ERI trajectory was associated with higher systolic BP (b = 8.8; p < 0.001) as was high overcommitment; declining ERI also showed a lesser association with higher BP. Associations between DC trajectories and BP were much smaller, and non-significant once controlled for overcommitment.

CONCLUSIONS

Self-assessed efforts, rewards, and overcommitment at work decline across pregnancy in our participants, while job control remains stable. Replication in a more diverse pregnant working population is warranted to confirm these results. These preliminary data suggest that further investigation into the factors that may be linked with improved work psychosocial climate during pregnancy may be useful in order to improve pregnancy outcomes.

Protecting Pregnant Workers while Fighting Sexism: Work-Pregnancy Balance and Pregnant Nurses' Resistance in Québec Hospitals: Protéger les travailleuses enceintes en luttant contre le sexisme: équilibre travail-grossesse et résistance d'infirmières enceintes dans des hôpitaux québécois

Women's workplaces should guarantee healthy pregnancies while supporting pregnant women as workers. In Québec (Canada), a pregnant worker exposed to a "danger" for herself or her fetus may ask her employer to be reassigned to other work appropriate to her skills. This approach differs from other regulatory contexts in North America in that protection of fetal and maternal health is embedded in the health and safety legislation. The advantage is that the pregnant worker is guaranteed access to her full salary, but some may question whether specific provisions for pregnant women single out such women and produce risks for their careers or, conversely, pregnancy should receive even more special consideration. These questions are discussed using the results of a qualitative analysis of interviews with pregnant nurses, their supervisors, and their union representatives in ten hospitals in Québec. We think that the management of pregnancy under this legislation generally protects health, but that, in the absence of true employer commitment to the health of all workers, undue burdens may be placed upon other members of the work team. Résumé Les lieux de travail des femmes devraient garantir des grossesses saines tout en soutenant les femmes enceintes en tant que travailleurs. Au Québec (Canada), une travailleuse enceinte exposée à un danger pour elle-même ou son fœtus peut demander à son employeur d'être réaffectée à d'autres tãches sans danger et adaptéches à ses compétences. Cette approche diffère des autres contextes réglementaires en Amérique du Nord en ce sens que la protection de la santé foetale et maternelle est intégrée dans la législation sur la santé et la sécurité. Certains peuvent se demander si des dispositions spécifiques pour les femmes enceintes singularisent ces travailleuses et contribuent à la précarisation de leur emploi. Ou, à l'inverse, si la grossesse devrait recevoir une considération encore plus spéciale. Ces questions sont discutées à la lumière du récit d infirmières enceintes, de gestionnaires et de représentants syndicaux responsables des dossiers de conciliation travail-grossesse dans dix hôpitaux du Québec. Nous constatons que la gestion de la grossesse en vertu de cette législation est généralement protectrice de la santé, mais qu'en l'absence d'un véritable engagement de l'employeur envers la santé de tous les travailleurs, des charges excessives peuvent être imposées aux autres membres de l'équipe de travail.

Review of hazards to female reproductive health in veterinary practice

OBJECTIVE To review publications that address female reproductive health hazards in veterinary practice, summarize best practices to mitigate reproductive risks, and identify current knowledge gaps. DESIGN Systematized review. SAMPLE English-language articles describing chemical, biological, and physical hazards present in the veterinary workplace and associations with adverse reproductive outcomes or recommendations for minimizing risks to female reproductive health. PROCEDURES Searches of the CAB abstracts database were performed in July 2012 and in May 2015 with the following search terms: veterinarians AND occupational hazards and vets.id AND occupational hazards.sh. Searches of the PubMed database were conducted in November 2012 and in May 2015 with the following medical subject heading terms: occupational exposure AND veterinarians; anesthetics, inhalation/adverse effects AND veterinarians; risk factors AND pregnancy AND veterinarians; pregnancy outcome AND veterinarians; and animal technicians AND occupational exposure. Two additional PubMed searches were completed in January 2016 with the terms disinfectants/toxicity AND female AND fertility/drug effects and veterinarians/psychology AND stress, psychological. No date limits were applied to searches. RESULTS 4 sources supporting demographic trends in veterinary medicine and 118 resources reporting potential hazards to female reproductive health were identified. Reported hazards included exposure to anesthetic gases, radiation, antineoplastic drugs, and reproductive hormones; physically demanding work; prolonged standing; and zoonoses. CONCLUSIONS AND CLINICAL RELEVANCE Demographic information suggested that an increasing number of women of reproductive age will be exposed to chemical, biological, and physical hazards in veterinary practice. Information on reproductive health hazards and minimizing risk, with emphasis on developing a safety-focused work culture for all personnel, should be discussed starting in veterinary and veterinary technical schools and integrated into employee training.

Non-occupational physical activity during pregnancy and the risk of preterm birth: a meta-analysis of observational and interventional studies

A meta-analysis was conducted to evaluate the association between non-occupational physical activity (PA) during pregnancy and the risk of preterm birth (PTB). By searching PubMed and EMBASE from inception to August 20, 2016, 25 observational studies (18 cohorts and 7 case-controls) and 12 interventional studies were identified. Comparing the highest to the lowest category of leisure-time PA during pregnancy, the pooled relative risk (RR) of PTB was 0.83 [95% confidence interval (CI) = 0.74-0.93] for cohort studies and 0.60 (95% CI = 0.43-0.84) for case-control studies. No overall significant association was found between domestic or commuting PA and the risk of PTB. In addition, PA intervention did not indicate significant beneficial effect on the risk of PTB. Evidence from the observational studies suggested that leisure-time, but not domestic or commuting, PA during pregnancy was inversely associated with the risk of PTB. The findings were not supported by small-scale and short-term interventional studies. Further research with objective measurement on leisure-time PA is warranted.

Pathways of job style and preterm low birth weight

Introduction

Preterm and low birth weight tend to occur as a direct result of prenatal risky behaviors, diseases, as well as fetal exposure to harmful social and environmental factors. The present study aimed to investigate the relationship between job style and preterm low birth weight.

Methods

The present case-control study was conducted in the Kamali hospital, Teheran, Iran in 2014. Participants included 156 mothers having a gestational age of less than 37 weeks and infants weighing less than 2500 gm. Additionally, the control group consisted of 433 mothers with a gestational age of over 37 weeks and having infants weighing between 2500–4000 gm. The data were collected using the Mother’s Lifestyle Scale (MLS) during pregnancy based on recognized social determinants of health and those developed by the researchers. The domain of the mother’s job style was assessed using a questionnaire consisting of 18 items on topics such as working conditions, job satisfaction, and perceived employer empathy. Higher overall scores in this instrument indicate the mother’s poorer job style. The data were analyzed using SPSS version 16 and Lisrel version 8.8 through a statistical path analysis.

Results

The model fit indices indicated that there was found to be high favorability, demonstrated that the model fit and that there were rational relationships (CFI=1, RMSEA=0.00), and showed that on the direct path that the mother’s job style had the most adverse effect (B=−0.3) with weight gain during pregnancy showing the most positive effect (B=0.16) on PLBW. The mother’s level of education was found to be the only variable that affected PLBW negatively in both the direct and indirect paths through the mother’s job style and household income (B=−0.17).

Conclusion

According the path analysis model, job style has a direct influence on preterm low birth weight. Thus, special consideration should be placed on aspects surrounding a mother’s job situation in order to prevent any adverse effects.

[Epidemiology and risk factors of preterm birth]

OBJECTIVE

To synthesize the available evidence regarding the incidence and several risk factors of preterm birth. To describe neonatal outcomes according to gestational age and to the context of delivery.

MATERIALS AND METHODS

Consultation of the Medline database.

RESULTS

In 2010, 11% of live births (15 million babies) occurred before 37 completed weeks of gestation worldwide. About 85% of these births were moderate to late preterm babies (32-36 weeks), 10% were very preterm babies (28-31 weeks) and 5% were extremely preterm babies (<28 weeks). In France, premature birth concerns 60,000 neonates every year, 12,000 of whom are born before 32 completed weeks of gestation. Half of them are delivered after spontaneous onset of labor or preterm premature rupture of the membranes, and the other half are provider-initiated preterm births. Several maternal factors are associated with preterm birth, including sociodemographic, obstetrical, psychological, and genetic factors; paternal and environmental factors are also involved. Gestational age is highly associated with neonatal mortality and with short- and long-term morbidities. Pregnancy complications and the context of delivery also have an impact on neonatal outcomes.

CONCLUSION

Preterm birth is one of the leading cause of the under-five mortality and of neurodevelopmental impairment worldwide; it remains a major public health issue.

Preterm birth and its associations with residence and ambient vehicular traffic exposure

BACKGROUND

Preterm birth (PTB) is a multifactorial disorder, and air pollution has been suggested to increase the risk of occurrence. However, large population studies controlling for multiple exposure measures in high-density settings with established commuter patterns are lacking.

OBJECTIVE

We performed a geospatial analysis with the use of a publicly available database to identify whether residence during pregnancy, specifically with regard to exposure to traffic density and mobility in urban and suburban neighborhoods, may be a contributing risk factor for premature delivery.

STUDY DESIGN

In our cohort study, we analyzed 9004 pregnancies with as many as 4900 distinct clinical and demographic variables from Harris County, Texas. On the basis of primary residency and occupational zip code information, geospatial analysis was conducted. Data on vehicle miles traveled (VMT) and percentages of inhabitants traveling to work were collected at the zip code level and additionally grouped by the three recognized regional commuter loop high-density thoroughfares resulting from two interstate/highway belts (inner, middle, and outer loops). PTB was categorized as late (34 1/7 to 36 6/7 weeks) and early PTB (22 1/7 to 33 6/7 weeks), and unadjusted odds ratios (OR) and adjusted ORs were ascribed.

RESULTS

PTB prevalence in our study population was 10.1% (6.8% late and 3.3% early preterm), which is in accordance with our study and other previous studies. Prevalence of early PTB varied significantly between the regional commuter loop thoroughfares [OR for inner vs outer loop: 0.58 (95% confidence interval, 0.39-0.87), OR for middle vs outer loop, 0.74 (0.57-0.96)]. The ORs for PTB and early PTB were shown to be lower in gravidae from neighborhoods with the highest VMT/acre [OR for PTB, 0.82 (0.68-0.98), OR for early PTB, 0.78 (0.62-0.98)]. Conversely, risk of PTB and early PTB among subjects living in neighborhoods with a high percentage of inhabitants traveling to work over a greater distance demonstrated a contrary tendency [OR for PTB, 1.18 (1.03-1.35), OR for early PTB, 1.48 (1.17-1.86)]. In logistic regression models, the described association between PTB and residence withstood and could not be explained by differences in maternal age, gravidity or ethnicity, tobacco use, or history of PTB.

CONCLUSION

While PTB is of multifactorial origin, the present study shows that community-based risk factors (namely urban/suburban location, differences in traffic density exposure, and need for traveling to work along high-vehicle density thoroughfares) may influence risk for PTB. Further research focusing on previously unrecognized community-based risk factors may lead to innovative future prevention measures.

Association of Maternal Working Condition with Low Birth Weight: The Social Determinants of Health Approach

Background:

The socioeconomic conditions have made more job opportunities available to women. This has created interest to conduct studies on the effect of working lifestyle on pregnancy outcomes.

Aim:

This study was conducted with the aim to assess the relationship between mothers' working status as a social determinant and the incidence of low birth weight (LBW) of the newborn.

Subjects and Methods:

This case–control study was conducted on 500 women with normal weight infants (control group) and 250 women with LBW infants (case group) in selected hospitals in Tehran. Data were collected using a researcher-made questionnaire, designed to assess the effect of mothers' prenatal lifestyle, as a social determinant, on LBW of the newborn. A section of the questionnaire involved assessment of mother's working condition in terms of the work environment, activities, and job satisfaction. Data were analyzed using Chi-square and logistic regression tests.

Results:

LBW among employed mothers was 5 times more likely than unemployed ones (odds ratio = 5.35, P < 0.001). Unfavorable work conditions such as humid environment, contact with detergents, and being in one standing or sitting position for long hours were significantly associated with LBW (P < 0.001).

Conclusion:

The present study showed that unfavorable work conditions were associated with LBW; therefore, they need special attention.

Characteristics of childbearing women, obstetrical interventions and preterm delivery: a comparison of the US and France

Preterm delivery rates have remained consistently higher in the US than France, but the reasons for this excess remain poorly understood. We examined if differences in socio-demographic risk factors or more liberal use of obstetrical interventions contributed to higher rates in the US. Data on singleton live births in 1995, 1998 and 2003 from US birth certificates and the French National Perinatal Survey were used to analyze preterm delivery rate by maternal characteristics (age, parity, marital status, education, race (US)/nationality (France), prenatal care and smoking). We distinguished between preterm deliveries with a cesarean or a labor induction and those without these interventions. Unadjusted and adjusted risk ratios (RR) for the US compared to France were estimated using log-binomial regression. Preterm delivery rates were 7.9 % in the US and 4.7 % in France (risk ratio [RR] = 1.7, 95 % confidence interval [CI] 1.6-1.8). The US had more teen mothers and late entry to prenatal care, but fewer women smoked, although adjustment for these and other confounders did not reduce RR (1.8, 95 % CI 1.7-1.9). Preterm delivery rates associated with labor induction or cesarean were 3.3 % in the US and 2.1 % in France (RR 1.6, 95 % CI 1.5-1.7); the corresponding rates for preterm delivery without these interventions were 4.5 and 2.5 % (RR 1.8, 95 % CI 1.7-1.9), respectively. Key socio-demographic risk factors and more obstetric intervention do not explain higher US preterm delivery rates. Avenues for future research include the impact of universal access to health services (universal health insurance?) on health care quality and the association between more generous social policies, stress and the risks of preterm delivery.

Periodontal Disease: A Possible Risk-Factor for Adverse Pregnancy Outcome

Bacterial invasion in subgingival sites especially of gram-negative organisms are initiators for periodontal diseases. The periodontal pathogens with persistent inflammation lead to destruction of periodontium. In recent years, periodontal diseases have been associated with a number of systemic diseases such as rheumatoid arthritis, cardiovascular-disease, diabetes mellitus, chronic respiratory diseases and adverse pregnancy outcomes including pre-term low-birth weight (PLBW) and pre-eclampsia. The factors like low socio-economic status, mother's age, race, multiple births, tobacco and drug-abuse may be found to increase risk of adverse pregnancy outcome. However, the same are less correlated with PLBW cases. Even the invasion of both aerobic and anerobic may lead to inflammation of gastrointestinal tract and vagina hence contributing to PLBW. The biological mechanism involved between PLBW and Maternal periodontitis is the translocation of chemical mediators of inflammation. Pre-eclampsia is one of the commonest cause of both maternal and fetal morbidity as it is characterized by hypertension and hyperprotenuria. Improving periodontal health before or during pregnancy may prevent or reduce the occurrences of these adverse pregnancy outcomes and, therefore, reduce the maternal and perinatal morbidity and mortality. Hence, this article is an attempt to review the relationship between periodontal condition and altered pregnancy outcome.

Maternal employment during pregnancy and birth outcomes: evidence from Danish siblings

I use Danish survey and administrative data to examine the impact of maternal employment during pregnancy on birth outcomes. As healthier mothers are more likely to work and health shocks to mothers may impact employment and birth outcomes, I combine two strategies: First, I control extensively for time-varying factors that may correlate with employment and birth outcomes, such as pre-pregnancy family income and maternal occupation, pregnancy-related health shocks, maternal sick listing, and health behaviors (smoking and alcohol consumption). Second, to account for remaining time-invariant heterogeneity between mothers, I compare outcomes of mothers' consecutive children. Mothers who work during the first pregnancy trimester have a lower risk of preterm birth. I find no effect on the probability of having a baby of small size for gestational age. To rule out that health selection of mothers between pregnancies drives the results, I focus on mothers whose change in employment status is likely not to be driven by underlying health (mothers who are students in one of their pregnancies and mothers with closely spaced births). Given generous welfare benefits and strict workplace regulations in Denmark, my findings support a residual explanation, namely, that exclusion from employment may stress mothers in countries with high-female employment rates.

Shift work, long working hours and preterm birth: a systematic review and meta-analysis

PURPOSE

Specific physical activities or working conditions are suspected for increasing the risk of preterm birth (PTB). The aim of this meta-analysis is to review and summarize the pre-existing evidence on the effect of shift work or long working hours on the risk of PTB.

METHODS

We conducted a systematic search in MEDLINE and EMBASE (1990-2013) for observational and intervention studies with original data. We only included articles that met our specific criteria for language, exposure, outcome, data collection and original data that were of at least of moderate quality. The data of the included studies were pooled.

RESULTS

Eight high-quality studies and eight moderate-quality studies were included in the meta-analysis. In these studies, no clear or statistically significant relationship between shift work and PTB was found. The summary estimate OR for performing shift work during pregnancy and the risk of PTB were 1.04 (95% CI 0.90-1.20). For long working hours during pregnancy, the summary estimate OR was 1.25 (95% CI 1.01-1.54), indicating a marginally statistically significant relationship but an only slightly elevated risk.

CONCLUSION

Although in many of the included studies a positive association between long working hours and PTB was seen this did reach only marginal statistical significance. In the studies included in this review, working in shifts or in night shifts during pregnancy was not significantly associated with an increased risk for PTB. For both risk factors, due to the lack of high-quality studies focusing on the risks per trimester, in particular the third trimester, a firm conclusion about an association cannot be stated.

Reproductive outcomes associated with noise exposure - a systematic review of the literature

Introduction: High noise exposure during critical periods in gestation is a potential stressor that may result in increased risk of implantation failure, dysregulation of placentation or decrease of uterine blood flow. This paper systematically reviews published evidence on associations between reproductive outcomes and occupational and environmental noise exposure. Methods: The Web of Science, PubMed and Embase electronic databases were searched for papers published between 1970 to June 2014 and via colleagues. We included 14 epidemiological studies related to occupational noise exposure and nine epidemiological studies related to environmental noise exposure. There was some evidence for associations between occupational noise exposure and low birthweight, preterm birth and small for gestational age, either independently or together with other occupational risk factors. Five of six epidemiologic studies, including the two largest studies, found significant associations between lower birthweight and higher noise exposure. There were few studies on other outcomes and study design issues may have led to bias in assessments in some studies. Conclusions: There is evidence for associations between noise exposure and adverse reproductive outcomes from animal studies. Few studies in have been conducted in humans but there is some suggestive evidence of adverse associations with environmental noise from both occupational and epidemiological studies, especially for low birthweight.