Work activities and risk of prematurity, low birth weight and pre-eclampsia: an updated review with meta-analysis

Physical job demands in pregnancy and associated musculoskeletal health and employment outcomes: a systematic review

OBJECTIVE

A decline in musculoskeletal health during pregnancy is an underappreciated adverse outcome of pregnancy that can have immediate and long-term health consequences. High physical job demands are known risk factors for nontraumatic musculoskeletal disorders in the general working population. Evidence from meta-analyses suggest that occupational lifting and prolonged standing during pregnancy may increase risk of adverse pregnancy outcomes. This systematic review examined associations between occupational lifting or postural load in pregnancy and associated musculoskeletal disorders and related sequalae.

DATA SOURCES

Five electronic databases (Medline, Embase, CINAHL, NIOSHTIC-2, and Ergonomic Abstracts) were searched from 1990 to July 2022 for studies in any language. A Web of Science snowball search was performed in December 2022. Reference lists were manually reviewed.

STUDY ELIGIBILITY CRITERIA

Eligible studies reported associations between occupational lifting or postural load and musculoskeletal health or sequelae (eg, employment outcomes) among pregnant and postpartum workers.

METHODS

Data were extracted using a customized form to document study and sample characteristics; and details of exposures, outcomes, covariates, and analyses. Investigators independently assessed study quality for 7 risk-of-bias domains and overall utility, with discrepant ratings resolved through discussion. A narrative synthesis was conducted due to heterogeneity.

RESULTS

Sixteen studies (11 cohort studies, 2 nested case-control studies, and 3 cross-sectional studies) from 8 countries were included (N=142,320 pregnant and N=1744 postpartum workers). Limited but consistent evidence with variable quality ratings, ranging from critical concern to high, suggests that pregnant workers exposed to heavy lifting (usually defined as ≥22 lbs or ≥10 kg) may be at increased risk of functionally limiting pelvic girdle pain and antenatal leave. Moreover, reports of dose-response relationships suggest graded risk levels according to lifting frequency, ranging from 21% to 45% for pelvic girdle pain and 58% to 202% for antenatal leave. Limited but consistent evidence also suggests that postural load increases the risk of employment cessation.

CONCLUSION

Limited but consistent evidence suggests that pregnant workers exposed to heavy lifting and postural load are at increased risk of pelvic girdle pain and employment cessation. Job accommodations to reduce exposure levels may promote safe sustainable employment for pregnant workers.

Prediction of pregnancy disorders in female workers in the industrial sector

Context

As female workers face a higher risk of exposure to workplace hazards than women in general, it is imperative that measures be put in place in the workplace to ensure safe and healthy pregnancies.

Objectives

This study aimed to analyze the effects of occupational hazards in the workplace environment on the potential for pregnancy disorders experienced by female workers.

Methods

This was an analytical, observational study with a case-control design. The participants were female workers who worked in industrial environments in both formal and nonformal industries. The inclusion criteria used in this study were female workers who had been or were pregnant at the time of the study, had worked in the industrial sector for at least one year, and did not smoke or consume alcohol. The samples were collected from 144 female workers. Midwives assisted in collecting data and conducting examinations of female workers. This study was conducted in Surabaya and Sidoarjo between June and December 2020. Data were analyzed descriptively, and a multivariable logistic regression test was performed. The study was conducted in accordance with the health protocols and prevention of COVID-19.

Results

The results showed that occupational hazards in the workplace environment that affect pregnancy disorders include workload (p = 0.004, OR = 28.676 (2.979-276.076); hot working environment (p = 0.014, OR = 3.077 (1.254-7.552); strong odors (p = 0.017, OR = 7.640 (1.436-40.656); shift work (p = 0.023, OR = 8.063 (1.337-48.623); irregular shift work (p = 0.018, OR = 7.371 (1.409-38.557); and night shift work (p = 0.015, OR = 11.780 (1.605-86.450).

Conclusions

Companies are expected to pay special attention to female workers regarding various workplace controls to prevent potential pregnancy-related disorders.

Impact of maternal posture on fetal physiology in human pregnancy: a narrative review

In numerous medical conditions, including pregnancy, gravity and posture interact to impact physiology and pathophysiology. Recent investigations, for example, pertaining to maternal sleeping posture during the third trimester and possible impact on fetal growth and stillbirth risk highlight the importance and potential clinical implications of the subject. In this review, we provide an extensive discussion of the impact of maternal posture on fetal physiology from conception to the postpartum period in human pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 242 studies from 1991 through 2021, inclusive, that met our inclusion criteria. Herein, we provide a synthesis of the resulting literature. In the first section of the review, we group the results by the impact of maternal posture at rest on the cervix, uterus, placenta, umbilical cord, amniotic fluid, and fetus. In the second section of the review, we address the impact on fetal-related outcomes of maternal posture during various maternal activities (e.g., sleep, work, exercise), medical procedures (e.g., fertility, imaging, surgery), and labor and birth. We present the published literature, highlight gaps and discrepancies, and suggest future research opportunities and clinical practice changes. In sum, we anticipate that this review will shed light on the impact of maternal posture on fetal physiology in a manner that lends utility to researchers and clinicians who are working to improve maternal, fetal, and child health.

Multiple Job Holding, Job Changes, and Associations with Gestational Diabetes and Pregnancy-Related Hypertension in the National Birth Defects Prevention Study

We used National Birth Defects Prevention Study data to investigate associations between working patterns shortly before and during pregnancy and gestational diabetes and pregnancy-related hypertension. We analyzed working patterns (multiple-job holders, job changers, single-job holders) during the three months before and during pregnancy for 8140 participants who delivered a live-born child without a birth defect. "Multiple-job holders" worked more than one job simultaneously, "job changers" worked more than one job with no overlap, and "single-job holders" (referent) worked one job. We used multivariable logistic regression to estimate associations between working pattern and each outcome, adjusting for maternal age and educational attainment at delivery. We explored effect measure modification by household income, peak weekly working hours, and maternal race/ethnicity. Multiple-job holders had higher odds of gestational diabetes (adjusted odds ratio [aOR]: 1.5; 95% confidence interval [CI]: 1.1-2.1) and pregnancy-related hypertension (aOR: 1.5; 95% CI: 1.0-2.2) compared with single-job holders. Multiple-job holders with a household income of more than 30,000 USD per year, 32-44 peak weekly working hours, and from racial/ethnic minority groups had higher odds of gestational diabetes compared with single-job holders in respective categories. Detailed occupational information is important for studies of occupation and maternal health.

The maternal factors associated with infant low birth weight: an umbrella review

BACKGROUND

In this umbrella review, we systematically evaluated the evidence from meta-analyses and systematic reviews of maternal factors associated with low birth weight.

METHODS

PubMed, Scopus, and Web of Science were searched to identify all relevant published studies up to August 2023. We included all meta-analysis studies (based on cohort, case-control, cross-sectional studies) that examined the association between maternal factors (15 risk factors) and risk of LBW, regardless of publication date. A random-effects meta-analysis was conducted to estimate the summary effect size along with the 95% confidence interval (CI), 95% prediction interval, and heterogeneity (I2) in all meta-analyses. Hedges' g was used as the effect size metric. The effects of small studies and excess significance biases were assessed using funnel plots and the Egger's test, respectively. The methodological quality of the included studies was assessed using the AMSTAR 2 tool.

RESULTS

We included 13 systematic Review with 15 meta-analysis studies in our study based on the inclusion criteria. The following 13 maternal factors were identified as risk factors for low birth weight: crack/cocaine (odds ratio [OR] 2.82, 95% confidence interval [CI] 2.26-3.52), infertility (OR 1.34, 95% CI 1.2-1.48), smoking (OR 2.00, 95% CI 1.76-2.28), periodontal disease (OR 2.41, 95% CI 1.67-3.47), depression (OR 1.84, 95% CI 1.34-2.53), anemia (OR 1.32, 95% CI 1.13-1.55), caffeine/coffee (OR 1.34, 95% CI 1.14-1.57), heavy physical workload (OR 1.87, 95% CI 1.00-3.47), lifting ≥ 11 kg (OR 1.59, 95% CI 1.02-2.48), underweight (OR 1.79, 95% CI 1.20-2.67), alcohol (OR 1.23, 95% CI 1.04-1.46), hypertension (OR 3.90, 95% CI 2.73-5.58), and hypothyroidism (OR 1.40, 95% CI 1.01-1.94). A significant negative association was also reported between antenatal care and low birth weight.

CONCLUSIONS

This umbrella review identified drug use (such as crack/cocaine), infertility, smoking, periodontal disease, depression, caffeine and anemia as risk factors for low birth weight in pregnant women. These findings suggest that pregnant women can reduce the risk of low birth weight by maintaining good oral health, eating a healthy diet, managing stress and mental health, and avoiding smoking and drug use.

Night work during pregnancy and small for gestational age: a Danish nationwide register-based cohort study

OBJECTIVE

The aim was to investigate the association between night work during pregnancy and risk of having a small for gestational age (SGA) child.

METHODS

This cohort study had payroll data with detailed information on working hours for employees in all Danish administrative regions (primarily hospital employees) between 2007 and 2015, retrieved from the Danish Working Hour Database. Pregnancies, covariates and outcome were identified from the national birth registry. We used logistic regression to investigate the association between intensity and duration of night work during the first 32 pregnancy weeks and SGA. The adjusted model included age, body mass index, socioeconomic status and smoking. Using quantitative bias analysis and G-estimation, we explored potential healthy worker survivor bias (HWSB).

RESULTS

The final cohort comprised 24 548 singleton pregnancies in 19 107 women, primarily nurses and medical doctors. None of the dimensions of night work were associated with an increased risk of SGA. We found a tendency towards higher risk of SGA in pregnancies where the women stopped having night shifts during pregnancy. Using G-estimation we found an OR<1 for the association between night work and SGA if all workers continued having night work during pregnancy compared with daywork only.

CONCLUSION

We found no increased risk of SGA in association with night work during pregnancy among healthcare workers. G-estimation was not precise enough to estimate the observed indication of HWSB. We need better data on pregnancy discomforts and complications to be able to safely rule out HWSB.

Perceptions of Job Hazards and Requests for Accommodation Among Pregnant Women in a Large Urban Hospital System

BACKGROUND

Many pregnant women remain uninformed about job accommodation options or have not been empowered to ask their employers.

METHODS

A cross-sectional survey of a sample base of pregnant women from late first through third trimester was conducted. Associations between job perception variables, work characteristics, race/ethnicity, and income were assessed using binary logistic regression.

RESULTS

Workers in service/support occupations were twice as likely as those in management to perceive need for job duty change and to request job accommodation. Perception of needed job change was higher when jobs had high physical demands and low substantive complexity.

CONCLUSIONS

We found positive relationships between highly physical work, perception of harm, and need for job change in pregnancy. Further research could explore worker/employer characteristics explaining why these perceptions did not translate into requesting and receiving job accommodation during pregnancy.

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].

Occupational Exposure during Pregnancy and Effects on Newborns: A Nested Case-Control Study

BACKGROUND

The protection of pregnant workers should be based on evidence regarding the risks to reproductive health from exposure to specific work environments and conditions. The objective of this study was to identify the effects on mothers and newborns resulting from environmental exposure to various occupational risks.

METHODS

The study cohort was composed of 399 women admitted to the Obstetrics/Postpartum ward at Hospital La Fe in Valencia, Spain. Face-to-face interviews were conducted to establish associations between workplace exposure during pregnancy and its effects on maternal and newborn health. Sex, anthropometric characteristics, and blood gas analysis in arterial and venous umbilical cord blood at delivery were collected.

RESULTS

A total of 138 women were exposed to biological and/or chemical risks, 122 to physical risks, and 139 at no risk of exposure. In the group with chemical and/or biological risks, the frequency of women who resorted to in vitro fertilization to achieve the studied pregnancy is less than half of the group exposed to physical risks, with statistically significant differences (p = 0.047). The mean values for the arterial analysis in both exposure groups were within average values, with similar pH values between them, but the mean values of PCO2 and PO2 were lower in the group of neonates of mothers exposed to physical risks, with a significant difference for arterial PO2 (p = 0.027).

CONCLUSION

Our analysis contributes evidence for planning and prioritizing preventive actions to protect women's reproductive health. The results suggest the continuation of a future project that would consider more factors and potentially increase the sample size.

Maternal occupational risk factors and preterm birth: Protocol for a systematic review and meta-analysis

INTRODUCTION

Preterm birth, which accounts for 33.1% of neonatal death globally, is the main cause of under-five mortality. A growing number of studies indicate that occupational risk factors during pregnancy are linked to an increased likelihood of poor pregnancy outcomes. The effect of physical occupational risks on preterm birth has received very little attention, and previous reviews have produced inconclusive results. This systematic review aims to update the evidence on the relationship between maternal physical occupational risks and preterm birth.

METHOD AND ANALYSIS

We will search electronic databases including Ovid Medline, Embase, Emcare, CINAHL, Scopus, and Web of science to find peer-reviewed studies examining the relationship between six common maternal physical occupational risks (heavy lifting, prolonged standing, heavy physical exertion, long working hours, shift work, and whole-body vibrations) and preterm birth. Articles published in English after 1 January 2000 will be included without geographic restrictions. Two reviewers will screen titles and abstracts independently, and then select full-text articles that meet inclusion criteria. Methodological quality of the included studies will be evaluated using the Joanna Briggs Institute (JBI) critical appraisal method. The quality of evidence across each exposure and the outcome of interest will be examined by using the GRADE (Grade of Recommendations, Assessment, Development, Evaluation) method. Accordingly, a high level of evidence will lead to "strong recommendations". A moderate level of evidence will lead to "practice considerations". For all evidence levels below moderate, the message will be "not enough evidence from the scientific literature to guide policymakers, clinicians, and patients. If data permits, a meta-analysis will be conducted using Stata Software. In case where meta-analysis is not possible, we will perform a formal narrative synthesis.

DISCUSSION AND CONCLUSION

Evidence suggests that preterm birth is linked to a number of maternal occupational risk factors. This systematic review will update, compile, and critically review the evidence on the effect of maternal physical occupational risk on preterm birth. This systematic review will provide guidance to support decision-makers including maternal and child health services, other health care providers, and government policy agencies.

TRIAL REGISTRATION

PROSPERO registration number: CRD42022357045.

A Comprehensive Review on Hot Ambient Temperature and its Impacts on Adverse Pregnancy Outcomes

INTRODUCTION

High workplace/ambient temperatures have been associated with Adverse Pregnancy Outcomes (APO). Millions of women working in developing nations suffer due to the rising temperatures caused by climate change. There are few pieces of research linking occupational heat stress to APO, and fresh evidence is required.

METHODOLOGY

We used databases including PubMed, Google Scholar, and Science Direct to search for research on high ambient/workplace temperatures and their effects. Original articles, newsletters, and book chapters were examined. The literature we analysed was categorised as follows: Heat, strain, and physical activity harming both mother and fetus. After categorising the literature, it was examined to identify the major results.

RESULTS

We found a definite association between heat stress and APOs such as miscarriages, premature birth, stillbirth, low birthweight, and congenital abnormalities in 23 research articles. Our work provides important information for future research into the biological mechanisms that create APOs and various prevention measures.

CONCLUSION

Our data suggest that temperature has long-term and short-term effects on maternal and fetal health. Though small in number, this study stressed the need for bigger cohort studies in tropical developing countries to create evidence for coordinated policies to safeguard pregnant women.

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.

Environmental and occupational factors and higher risk of couple infertility: a systematic review study

Background

Infertility is a global health problem that represents an increasing trend due to new lifestyles following technological advances since individuals are facing more risk factors than before. The present systematic review study aimed to investigate the impact of environmental and occupational factors on reproductive parameters and increased risk of couple infertility.

Main body

Scopus, PubMed, SID, and Web of Science databases were searched for the available observational (i.e., cohort, case-control, and cross-sectional) systematic review, meta-analysis, and clinical trial studies between 2007 and 2019. To this end, keywords such as ‘Environmental exposure’, ‘Occupational exposure’, ‘Environmental pollutants’, ‘Environmental pollution’, ‘Couple infertility’, ‘Sterility’, and ‘Sub-fertility’ were used. The retrieved investigations examined the impact of environmental and occupational risk factors on reproductive indices and increased infertility risk. Totally, 66 out of 9519 papers were evaluated after considering the inclusion and exclusion criteria. The reported risk factors in the reviewed studies were heavy metals, cigarette smoking, and exposure to chemicals through consumer goods, urban life, and proximity to main roads. In addition, occupational factors included heavy physical activity, prolonged sitting, exposure to a hot environment, contact with formaldehyde, pesticides, insecticides, mechanical vibration, and contact with ionizing radiation, all of which affected the reproductive parameters. However, some researchers found no significant associations in this regard.

Short conclusion

In general, individuals with known impairments in reproductive parameters were more exposed to risk factors. Nonetheless, more studies are needed to determine the risk of infertility in the population.

Association between maternal shift work during pregnancy child overweight and metabolic outcomes in early childhood

Background

Previous studies found that maternal shift work during pregnancy was associated with many reproductive hazards, including small for gestational age, preterm birth, stillbirth, and neurodevelopmental impairment. Some studies also showed that these children are more likely to become overweight in early childhood. However, the association with metabolic factors, such as insulin resistance and dyslipidemia, was less studied. Hence, we aimed to understand better the relationship between maternal shift work during pregnancy and the risk of childhood overweight and metabolic outcomes. Confounding factors were also discussed, including diet, exercise, and demographical factors.

Methods

We enrolled pregnant women before delivery in the Taiwan Birth Panel Study (TBPS) II conducted between 2010 and 2012, and followed the children of these participants in 2018. The objective of this study is to investigate the influence of prenatal and postnatal factors on infant and early childhood health. During the follow-up in 2018, we checked children's demographic data, obtained blood specimens, and checked their blood sugar, blood insulin, and lipid profiles. Structured questionnaires were used to evaluate demographic data. Multiple linear and logistic regressions were used to examine the associations between maternal shift work during pregnancy and child overweight, metabolic disorders, such as HOMA-IR, and lipid profiles.

Results

In this study, we included 407 mother-children pairs with different work shifts (350 day workers and 57 shift workers), and a sub-population without underweight children was also created (290 day workers and 47 shift workers). Shift work during pregnancy was associated with a higher Homeostasis Model Assessment-Insulin Resistance index (HOMA-IR) and a higher odds ratio for overweight in children born from mothers doing shift work during pregnancy after adjustment. The findings were attenuated when we investigated the effect of shift work before pregnancy.

Conclusion

Our study suggested that maternal shift work during pregnancy was associated with child overweight and insulin resistance in early childhood.

Incidence and Risk Factors for Low Birthweight and Preterm Birth in Post-Conflict Northern Uganda: A Community-Based Cohort Study

BACKGROUND

Annually, an estimated 20 million (13%) low-birthweight (LBW) and 15 million (11.1%) preterm infants are born worldwide. A paucity of data and reliance on hospital-based studies from low-income countries make it difficult to quantify the true burden of LBW and PB, the leading cause of neonatal and under-five mortality. We aimed to determine the incidence and risk factors for LBW and preterm birth in Lira district of Northern Uganda.

METHODS

This was a community-based cohort study, nested within a cluster-randomized trial, designed to study the effect of a combined intervention on facility-based births. In total, 1877 pregnant women were recruited into the trial and followed from 28 weeks of gestation until birth. Infants of 1556 of these women had their birthweight recorded and 1279 infants were assessed for preterm birth using a maturity rating, the New Ballard Scoring system. Low birthweight was defined as birthweight <2.5kg and preterm birth was defined as birth before 37 completed weeks of gestation. The risk factors for low birthweight and preterm birth were analysed using a multivariable generalized estimation equation for the Poisson family.

RESULTS

The incidence of LBW was 121/1556 or 7.3% (95% Confidence interval (CI): 5.4-9.6%). The incidence of preterm births was 53/1279 or 5.0% (95% CI: 3.2-7.7%). Risk factors for LBW were maternal age ≥35 years (adjusted Risk Ratio or aRR: 1.9, 95% CI: 1.1-3.4), history of a small newborn (aRR: 2.1, 95% CI: 1.2-3.7), and maternal malaria in pregnancy (aRR: 1.7, 95% CI: 1.01-2.9). Intermittent preventive treatment (IPT) for malaria, on the other hand, was associated with a reduced risk of LBW (aRR: 0.6, 95% CI: 0.4-0.8). Risk factors for preterm birth were maternal HIV infection (aRR: 2.8, 95% CI: 1.1-7.3), while maternal education for ≥7 years was associated with a reduced risk of preterm birth (aRR: 0.2, 95% CI: 0.1-0.98) in post-conflict northern Uganda.

CONCLUSIONS

About 7.3% LBW and 5.0% PB infants were born in the community of post-conflict northern Uganda. Maternal malaria in pregnancy, history of small newborn and age ≥35 years increased the likelihood of LBW while IPT reduced it. Maternal HIV infection was associated with an increased risk of PB compared to HIV negative status. Maternal formal education of ≥7 years was associated with a reduced risk of PB compared to those with 0-6 years. Interventions to prevent LBW and PBs should include girl child education, and promote antenatal screening, prevention and treatment of malaria and HIV infections.

Shift work and sleep duration are associated with adverse pregnancy outcomes in a predominantly Latinx population with high rates of obesity

Background

Shift work has been associated with adverse pregnancy outcomes. The objective of this study was to evaluate the association between sleep disturbances and adverse pregnancy outcomes.

Methods and findings

This was a secondary analysis of a prospective study of participants enrolled in a prospective observational study wherein gravidae were screened for sleep apnea (2010–2012). A screening questionnaire with standard sleep apnea questionnaires as well as novel items about shift work and nocturnal sleep duration was administered at a prenatal care visit. Short sleep duration was defined as less than 7 hours. Prolonged sleep duration was defined as greater than 9 hours.

In a cohort of 1125 pregnant people, 9.4% reported shift work at the time of screening. Gravidae who reported shift work were more likely than gravidae who reported no shift work to develop preeclampsia (28.3% versus 13.0%, P<0.001), preeclamspsia with severe features (16.0% versus 8.5%, P = 0.010), gestational diabetes (28.3% versus 19.9%, P = 0.041), and a composite of adverse obstetric outcomes (61.3% versus 47.8%, P = 0.008). After adjusting for potentially confounding variables, shift work was associated with an increased risk for preeclampsia with (adjusted relative risk (aRR) 1.70, 95% CI 1.03–2.79, p = 0.036) and without (aRR 2.03, 95% CI 1.43–2.90, p<0.001) severe features, and gestational diabetes mellitus class A1 (aRR 1.47, 95% CI 1.05–2.05, p = 0.023) and class A2 (aRR 1.67, 95% CI 1.13–2.44, p = 0.009). Sleep duration was associated with gestational diabetes (31.3% among those with short sleep duration, 25.2% among those with normal sleep duration and 14.0% among those with prolonged sleep duration, P<0.001) and gestational diabetes class A2 (29.5%, 17.9%, and 10.1%, respectively, P<0.001). Gravidae with prolonged sleep duration experienced less composite adverse pregnancy outcomes at 42.6% compared to 57.4% for those with short sleep duration or 52.5% for those with normal sleep duration, P = 0.002.

Conclusions

Shift work and sleep duration are both associated with adverse pregnancy outcomes. Further research on the impact of sleep disturbance on pregnancy outcomes is warranted.

Evaluation of a pilot consultation for maternity protection at work in Switzerland

STUDY AIMS

Switzerland's Labour Law and its Ordonnance on Maternity Protection aim to protect the health of pregnant employees and their unborn children while enabling them to continue to pursue their professional activities. Some companies encounter difficulties implementing the law's provisions. The Department of Occupational and Environmental Health, part of the Center for Primary Care and Public Health (Unisanté), has provided specialist occupational medicine consultations for pregnant employees since 2015. This study aimed to evaluate how well Swiss' maternity protection legislation is implemented by examining a list of relevant indicators measured during the occupational health consultation. The study also sought to investigate the consultation support provided to the relevant stakeholders and the adjustments made to pregnant employees' working conditions.

METHODS

Descriptive variables and indicators relative to the application of the Swiss maternity protection legislation for 83 pregnant employees were collected during the consultation's pilot phase (between 2015 and 2016). Descriptive statistics and cross-analyses of these indicators were made.

RESULTS

Most pregnant employees faced multiple exposures to occupational risks. Preventive risk analyses were rare. Few adjustments to workstations were proposed. We found a tendency for employees to leave their workstations early on in their pregnancies due to sick leave certificate prescriptions. Specialist consultation and collaboration with occupational health physicians to recommend interventions for pregnant employees can provide significant benefits and help some pregnant women to continue at their workstations with appropriate adjustments.

DISCUSSION

A specialised occupational health consultation is a useful instrument for identifying occupational hazards for both the pregnant woman and her unborn child. It is also an opportunity to explain employers' legal responsibilities and obligations to safeguard the health of their pregnant employees and to give specific advice for their company's situation. This consultation also enables employers to maintain their employees' valuable professional competencies in the workplace for as long as possible. Finally, occupational health consultation helps and supports healthcare providers who must, according to the law, make decisions about whether pregnant employees can continue working safely or not.

Evaluation of Adverse Pregnancy Outcomes in Physicians Compared With Nonphysicians

IMPORTANCE

Physicians may be at risk of pregnancy complications due to prolonged work hours, overnight shifts, occupational hazards, and older maternal age at first birth compared with nonphysicians. Observational studies of physicians, including comparisons across physician specialties, are needed.

OBJECTIVE

To compare adverse maternal and perinatal outcomes between pregnant physicians and nonphysicians and between physicians of different specialties.

DESIGN, SETTING, AND PARTICIPANTS

A population-based retrospective cohort study was conducted in Ontario, Canada. Participants included physicians and nonphysician comparators residing in high-income areas who experienced a birth at 20 or more weeks' gestation from April 1, 2002, to November 26, 2018. Data analysis was performed from December 2020 to March 2022.

EXPOSURES

Physician occupation and physician specialty.

MAIN OUTCOMES AND MEASURES

Severe maternal morbidity (in pregnancy and up to 42 days' post partum) and severe neonatal morbidity (up to hospital discharge among live-born infants) were the primary outcomes. Logistic regression under a generalized estimating equations approach was used to compare outcomes between physicians and nonphysicians, accounting for potentially more than 1 pregnancy per woman. Odds ratios were adjusted (aOR) for maternal age, parity, previous preterm birth, calendar year, immigration status, comorbidities, multiple gestation, and mode of delivery.

RESULTS

A total of 10 489 births occurred among 6161 licensed physicians, and 298 683 births occurred among 211 191 nonphysician counterparts. Physicians were older (median [IQR] age, 34 [31-36] vs 32 [29-35] years) and more likely to be nulliparous (5049 [48.1%] vs 128 961 [43.2%]) compared with nonphysicians. Severe maternal morbidity was more likely to occur among physicians than nonphysicians (unadjusted OR, 1.21; 95% CI, 1.04-1.41) but not after adjusting for study covariates (aOR, 1.13; 95% CI, 0.97-1.32). Severe neonatal morbidity was less likely to occur among infants of physicians than infants of nonphysicians (aOR, 0.79; 95% CI, 0.72-0.87). Compared with family physicians, neither nonsurgical specialists (aOR, 1.12; 95% CI, 0.82-1.53) nor surgical specialists (aOR, 1.43; 95% CI, 0.74-2.76) were at increased risk of severe maternal morbidity. Similar findings were observed for severe neonatal morbidity (nonsurgical specialists: aOR, 0.98; 95% CI, 0.80-1.19; surgical specialists: aOR, 1.08; 95% CI, 0.68-1.71).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that female physicians may be at slightly higher risk of severe maternal morbidity. This association appeared to be mediated by their tendency to delay childbearing compared with nonphysicians. Newborns of physicians appear to experience less morbidity. Such differences were not observed between physician specialty groups.

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.

Biomechanical and organisational constraints of pregnant women at work: definition of exposure levels using a consensus method (Delphi)

OBJECTIVES

To identify the biomechanical and organisational constraints that influence pregnancy outcomes and define the exposure levels at which the risks for pregnancy become significant.

SETTING AND PARTICIPANTS

We applied a consensus method (Delphi) consisting of a literature review followed by expert opinions on exposure levels. The group of experts was made up of 12 people from different medical specialities and working in various structures in France.

OUTCOME MEASURES

The studied variables were: (1) exposure: night work/shift work, weekly hours at work, lifting of heavy loads, prolonged standing and multiple exposure and (2) pregnancy outcomes: prematurity, low birth weight and spontaneous miscarriages.

RESULTS

The consensus method resulted in the following recommendations. The time spent working must not exceed 40 hours/week; in the absence of a consensus on the level of exposure, night and/or shift work must be avoided; prolonged standing must not exceed 3 hours/day; lifting must be limited to carrying loads <11 kg, with a daily load <100 kg; multiple exposure must be avoided, in particular: vibration, night work/shift work, time spent working exceeding 40 hours/week, prolonged standing and lifting of heavy loads.

CONCLUSIONS

These results could help the occupational physician to address the question of whether an exposed employee should remain at work, considering her individual characteristics (medical history, family situation, socioeconomic level, etc) in consultation with pregnancy specialists (obstetricians, midwives).

What to Expect When Expecting in Lab: A Review of Unique Risks and Resources for Pregnant Researchers in the Chemical Laboratory

Pregnancy presents a unique risk to chemical researchers due to their occupational exposures to chemical, equipment, and physical hazards in chemical research laboratories across science, engineering, and technology disciplines. Understanding “risk” as a function of hazard, exposure, and vulnerability, this review aims to critically examine the state of the science for the risks and associated recommendations (or lack thereof) for pregnant researchers in chemical laboratories (labs). Commonly encountered hazards for pregnant lab workers include chemical hazards (organic solvents, heavy metals, engineered nanomaterials, and endocrine disruptors), radiation hazards (ionizing radiation producing equipment and materials and nonionizing radiation producing equipment), and other hazards related to the lab environment (excessive noise, excessive heat, psychosocial stress, strenuous physical work, and/or abnormal working hours). Lab relevant doses and routes of exposure in the chemical lab environment along with literature and governmental recommendations or resources for exposure mitigation are critically assessed. The specific windows of vulnerability based on stage of pregnancy are described for each hazard, if available. Finally, policy gaps for further scientific research are detailed to enhance future guidance to protect pregnant lab workers.

Shift and night work during pregnancy and preterm birth-a cohort study of Swedish health care employees

BACKGROUND

Previous studies of preterm birth (PTB) concerning night work have been inconclusive and partly limited by imprecise data on working schedules. This study investigated the risk of PTB in relation to detailed, registry-based data on working hours.

METHODS

In a register-based prospective cohort study, we identified 4970 singleton births with information on PTB from the Swedish Medical Birth Register of health care employees in Stockholm. Day-by-day information on working hours 2008-16 was obtained from a computerized employee register. Odds ratios (ORs) of PTB according to work hour characteristics were analysed by logistic regression adjusted for mother's age, stature, body mass index (BMI), parity, smoking habits, education, profession and country of birth.

RESULTS

There was an increased risk of PTB among those who frequently worked night shifts (>25 times) [OR, 1.62; 95% confidence interval (CI), 1.03-2.53] and who ever worked ≥3 consecutive night shifts (OR, 1.43; 95% CI, 1.03-1.99) during the first trimester. Frequently (> 8 times) working 3 or more consecutive nights, and frequently (>18 times) having quick returns from night shifts (<28 h) during the first trimester showed 3-4 fold increased risk of PTB. Moreover, working frequent (>20 times) long shifts (≥10 h) (OR 1.63; 95% CI, 1.07-2.49) during the first trimester and working any Week >40 h (OR 2.05; 95% CI, 1.31-3.22) during the third trimester were associated with PTB.

CONCLUSIONS

In this cohort of Swedish health care employees with registry-based data on working hours, night work, especially working frequent consecutive nights, and quick returns from night shifts during the first trimester were associated with increased risk of PTB among pregnant women.

Validation and development of models using clinical, biochemical and ultrasound markers for predicting pre-eclampsia: an individual participant data meta-analysis

BACKGROUND

Pre-eclampsia is a leading cause of maternal and perinatal mortality and morbidity. Early identification of women at risk is needed to plan management.

OBJECTIVES

To assess the performance of existing pre-eclampsia prediction models and to develop and validate models for pre-eclampsia using individual participant data meta-analysis. We also estimated the prognostic value of individual markers.

DESIGN

This was an individual participant data meta-analysis of cohort studies.

SETTING

Source data from secondary and tertiary care.

PREDICTORS

We identified predictors from systematic reviews, and prioritised for importance in an international survey.

PRIMARY OUTCOMES

Early-onset (delivery at < 34 weeks' gestation), late-onset (delivery at ≥ 34 weeks' gestation) and any-onset pre-eclampsia.

ANALYSIS

We externally validated existing prediction models in UK cohorts and reported their performance in terms of discrimination and calibration. We developed and validated 12 new models based on clinical characteristics, clinical characteristics and biochemical markers, and clinical characteristics and ultrasound markers in the first and second trimesters. We summarised the data set-specific performance of each model using a random-effects meta-analysis. Discrimination was considered promising for C-statistics of ≥ 0.7, and calibration was considered good if the slope was near 1 and calibration-in-the-large was near 0. Heterogeneity was quantified using I ² and τ². A decision curve analysis was undertaken to determine the clinical utility (net benefit) of the models. We reported the unadjusted prognostic value of individual predictors for pre-eclampsia as odds ratios with 95% confidence and prediction intervals.

RESULTS

The International Prediction of Pregnancy Complications network comprised 78 studies (3,570,993 singleton pregnancies) identified from systematic reviews of tests to predict pre-eclampsia. Twenty-four of the 131 published prediction models could be validated in 11 UK cohorts. Summary C-statistics were between 0.6 and 0.7 for most models, and calibration was generally poor owing to large between-study heterogeneity, suggesting model overfitting. The clinical utility of the models varied between showing net harm to showing minimal or no net benefit. The average discrimination for IPPIC models ranged between 0.68 and 0.83. This was highest for the second-trimester clinical characteristics and biochemical markers model to predict early-onset pre-eclampsia, and lowest for the first-trimester clinical characteristics models to predict any pre-eclampsia. Calibration performance was heterogeneous across studies. Net benefit was observed for International Prediction of Pregnancy Complications first and second-trimester clinical characteristics and clinical characteristics and biochemical markers models predicting any pre-eclampsia, when validated in singleton nulliparous women managed in the UK NHS. History of hypertension, parity, smoking, mode of conception, placental growth factor and uterine artery pulsatility index had the strongest unadjusted associations with pre-eclampsia.

LIMITATIONS

Variations in study population characteristics, type of predictors reported, too few events in some validation cohorts and the type of measurements contributed to heterogeneity in performance of the International Prediction of Pregnancy Complications models. Some published models were not validated because model predictors were unavailable in the individual participant data.

CONCLUSION

For models that could be validated, predictive performance was generally poor across data sets. Although the International Prediction of Pregnancy Complications models show good predictive performance on average, and in the singleton nulliparous population, heterogeneity in calibration performance is likely across settings.

FUTURE WORK

Recalibration of model parameters within populations may improve calibration performance. Additional strong predictors need to be identified to improve model performance and consistency. Validation, including examination of calibration heterogeneity, is required for the models we could not validate.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015029349.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 72. See the NIHR Journals Library website for further project information.

Ergonomic Stressors Among Pregnant Healthcare Workers: Impact on pregnancy outcomes and recommended safety practices

Workplace environment can have a considerable impact on the physical, psychological and maternal health of pregnant healthcare workers. This article aimed to summarise the impact of work-related ergonomic stressors on pregnancy outcomes for healthcare workers, along with potential interventions to resolve these stressors. A narrative review analysis using the Pearl Growing Strategy was conducted between February 2019 and June 2020 to identify English-language articles published between 2000 and 2020. A total of 89 studies were identified from the SCOPUS (Elsevier, Amsterdam, Netherlands), MEDLINE® (National Library of Medicine, Bethesda, Maryland, USA) databases and Google Scholar (Google LLC, Menlo Park, California, USA). The results indicated that poor work-related ergonomics had detrimental effects on pregnancy outcomes, resulting in spontaneous abortions, preterm delivery, low birth weight babies and infertility. Policymakers and employers should conduct ergonomic assessments and implement appropriate practices to ensure the safety of pregnant healthcare workers.

The Health Care Provider's Role in Securing Work Accommodations for Pregnant and Postpartum Patients

Most women today are the primary, sole, or cobreadwinners for their families; their continued ability to work during and after pregnancy is crucial for their families' well-being. Midwives and other health care providers are regularly asked to provide work notes for patients who need adjustments to how, when, or where their job is done to continue working while maintaining a healthy pregnancy or breastfeeding. Whereas an improperly written work note can result in the patient being forced out on leave or losing their job, an effectively written work note from a health care provider can ensure the patient will receive the adjustments they need to stay safe and healthy on the job. Health care providers can also play an important role by incorporating discussions about workplace issues into care conversations. This article provides an overview of pregnancy-related employment rights, guidelines for writing effective work notes, and a discussion of common workplace issues patients face and how health care providers can respond.

Status and related factors of depression, perceived stress, and distress of women at home rest with threatened preterm labor and women with healthy pregnancy in Taiwan

BACKGROUND

Women with threatened preterm labor (TPTL) resting at home face several life challenges, but their psychological well-being has been ignored. This study aimed to explore the status and related factors of the psychological status of women with TPTL resting at home, and to compare the psychological status differences between TPTL and healthy pregnant women.

METHODS

A cross-sectional, multiple time-point study was conducted to repeatedly assess depression, perceived stress, and distress in 49 TPTL women and 62 healthy pregnant women during pregnancy in Taiwan. Mann-Whitney U tests were used to compare the psychological status differences between these women and the generalized estimating equation was used to identify the factors related to their psychological status.

RESULTS

The TPTL women's perceived stress at 24-27 weeks (p=0.047) and 32-35 weeks (p=0.04) and distress at each time point was significantly greater than that of healthy pregnant women (p<0.001). The common distress experienced by TPTL women was the inability to provide self-care and family care, the baby's health and safety, and to request leave from work for bed rest. Positive personalities, gestational age, preterm birth history, follow-up status and employment have been shown to be related to the psychological status of TPTL women.

LIMITATIONS

The major limitation of this study is the small sample size.

CONCLUSION

This study contributed to a better understanding of the emotional burdens of women with TPTL resting at home. Such findings highlight the need for constructing effective interventions to alleviate the psychological burden of these women.

Manager-oriented intervention to reduce absence among pregnant employees in the healthcare and daycare sector: a cluster randomised trial

OBJECTIVE

The aim was to test if targeting managers with an educational intervention reduces absence among pregnant employees.

METHODS

The study was a non-blinded cluster randomised trial conducted in hospitals and daycare institutions from two administrative Danish Regions and two Danish municipalities. Clusters (work units) were assigned randomly and non-blinded to either (1) intervention, where all managers were invited to participate in a 3-hour seminar addressing needs and options for adjustment of work in pregnancy, or (2) control, with practice as usual. The primary outcome based on payroll data was long-term pregnancy-related absence, defined as ≥12.5% cumulated absence during pregnancy weeks 1-32. Intention-to-treat analysis was applied using mixed logistic regression.

RESULTS

Ninety work units were included (56 hospital departments and 34 daycare units) with 451 pregnant employees in the intervention group and 464 in the control group. Work units had on average 11 pregnant employees with no difference between the groups. 103 of the 216 invited managers (48%) participated in a the 3-hour seminar. In the intervention group, 154 (34%) had long-term pregnancy-related absence during pregnancy weeks 1-32 vs 166 (36%) in the control group. Relative odds of having long-term pregnancy-related absence, when being in the intervention group, was 1.06 (95% CI 0.71 to 1.58), with an interclass correlation coefficient of 0.07.

CONCLUSION

An educational intervention targeting managers did not reduce pregnancy-related absence among pregnant employees.

TRIAL REGISTRATION NUMBER

NCT03002987.

[Pregnancy outcomes in medical residents: An observational study]

OBJECTIVE

To describe the working conditions during pregnancy of medical residents. To describe adverse outcomes and to identify professional factors associated with these outcomes.

METHODS

This observational study described the working conditions during pregnancy of medical residents and the outcomes. An online questionnaire was sent to the 773 residents, of all specialties, enrolled in medical school in Nancy, France.

RESULTS

Three hundred and one residents participated in the study (38,9 %). The average daily working time of students was closed to 9hours, regardless the trimester, with a break time that rarely exceed one hour. Residents said continued to be on call beyond 10 weeks of gestation in 87.5 % of cases, the legal term for stopping these. The rate of adverse outcomes was 42.6 % (23/54). The rates of preterm labors and preterm births were 22.5 % and 15 % respectively. A significant association was found between working more than 10hours per day during 2nd trimester and adverse outcomes.

CONCLUSION

A strengthening of health monitoring at work with adaptation of workstation, information campaigns, as well as the designation of resource persons within the faculties seem essential.

How to schedule night shift work in order to reduce health and safety risks

Objectives This discussion paper aims to provide scientifically based recommendations on night shift schedules, including consecutive shifts, shift intervals and duration of shifts, which may reduce health and safety risks. Short-term physiological effects in terms of circadian disruption, inadequate sleep duration and quality, and fatigue were considered as possible links between night shift work and selected health and safety risks, namely, cancer, cardio-metabolic disease, injuries, and pregnancy-related outcomes. Method In early 2020, 15 experienced shift work researchers participated in a workshop where they identified relevant scientific literature within their main research area. Results Knowledge gaps and possible recommendations were discussed based on the current evidence. The consensus was that schedules which reduce circadian disruption may reduce cancer risk, particularly for breast cancer, and schedules that optimize sleep and reduce fatigue may reduce the occurrence of injuries. This is generally achieved with fewer consecutive night shifts, sufficient shift intervals, and shorter night shift duration. Conclusions Based on the limited, existing literature, we recommend that in order to reduce the risk of injuries and possibly breast cancer, night shift schedules have: (i) ≤3 consecutive night shifts; (ii) shift intervals of ≥11 hours; and (iii) ≤9 hours shift duration. In special cases - eg, oil rigs and other isolated workplaces with better possibilities to adapt to daytime sleep - additional or other recommendations may apply. Finally, to reduce risk of miscarriage, pregnant women should not work more than one night shift in a week.

Reproductive patterns, pregnancy outcomes and parental leave practices of women physicians in Ontario, Canada: the Dr Mom Cohort Study protocol

INTRODUCTION

Surveys and qualitative studies suggest that women physicians may delay childbearing, be at increased risk of adverse peripartum complications when they do become pregnant, and face discrimination and lower earnings as a result of parenthood. Observational studies enrolling large, representative samples of women physicians are needed to accurately evaluate their reproductive patterns, pregnancy outcomes, parental leave practices and earnings. This protocol provides a detailed research plan for such studies.

METHODS AND ANALYSIS

The Dr Mom Cohort Study encompasses a series of retrospective observational studies of women physicians in Ontario, Canada. All practising physicians in Ontario are registered with the College of Physicians and Surgeons of Ontario (CPSO). By linking a dataset of physicians from the CPSO to existing provincial administrative databases, which hold health data and physician billing records, we will be able to retrospectively assess the healthcare utilisation, work practices and pregnancy outcomes of women physicians at the population level. Specific outcomes of interest include: (1) rates and timing of pregnancy; (2) pregnancy-related care and complications; and (3) duration of parental leave and subsequent earnings, each of which will be evaluated with regression methods appropriate to the form of the outcome. We estimate that, at minimum, 5000 women physicians will be eligible for inclusion.

ETHICS AND DISSEMINATION

This protocol has been approved by the Research Ethics Board at St. Michael's Hospital in Toronto, Ontario, Canada (#18-248). We will disseminate findings through several peer-reviewed publications, presentations at national and international meetings, and engagement of physicians, residency programmes, department heads and medical societies.

Preterm parturition and pre-eclampsia: The confluence of two great gestational syndromes

BACKGROUND

Preterm birth (PTB) and pre-eclampsia independently, and frequently concurrently, adversely affect the pregnancy outcomes of millions of mothers and infants worldwide each year.

OBJECTIVES

To fill the gap between PTB and pre-eclampsia, which continue to constitute the two most important current global challenges to maternal and perinatal health.

METHODS

Pubmed, Embase, and Cochrane databases were searched from inception until December 2019 using the terms spontaneous PTB (SPTB), indicated preterm delivery (IPTD), early-onset pre-eclampsia, and pre-eclampsia.

RESULTS

History of PTB and pre-eclampsia were the strongest risk factors contributing to the occurrence of SPTB or IPTB. The risk of PTB and pre-eclampsia among non-Hispanic African American women was higher than the rate among all other racial/ethnic groups in the United States. Low-dose aspirin (LDA) has been reported to reduce the risk of pre-eclampsia by at least 10% and PTB by at least 14%. Lastly, women and their fetuses who develop early-onset pre-eclampsia are at higher risk for developing hypertension and cardiovascular disease later in life.

CONCLUSIONS

While better clarity is needed, efforts to coordinate prevention of both PTB and pre-eclampsia, even though imperfect, are critically important as part of any program to make motherhood as safe as possible.

Pregnancy vs. paycheck: a qualitative study of patient's experience with employment during pregnancy at high risk for preterm birth

Background

Pregnant women with a history of preterm birth are at risk for recurrence, often requiring frequent prenatal visits for close monitoring and/or preventive therapies. Employment demands can limit uptake and adherence to recommended monitoring and preterm birth prevention therapies.

Method

We conducted a qualitative descriptive study using in-depth interviews (IDIs) of pregnant women with a history of preterm birth. IDIs were conducted by trained qualitative interviewers following a semi-structured interview guide focused on uncovering barriers and facilitators to initiation of prenatal care, including relevant employment experiences, and soliciting potential interventions to improve prompt prenatal care initiation. The IDIs were analyzed via applied thematic analysis.

Results

We described the interview findings that address women’s employment experiences. The current analysis includes 27 women who are majority self-described as non-Hispanic Black (74%) and publically insured (70%). Participants were employed in a range of professions; food services, childcare and retail were the most common occupations. Participants described multiple ways that being pregnant impacted their earning potential, ranging from voluntary work-hour reduction, involuntary duty hour reductions by employers, truncated promotions, and termination of employment. Participants also shared varying experiences with workplace accommodations to their work environment and job duties based on their pregnancy. Some of these accommodations were initiated by a collaborative employee/employer discussion, others were initiated by the employer’s perception of safe working conditions in pregnancy, and some accommodations were based on medical recommendations. Participants described supportive and unsupportive employer reactions to requests for accommodations.

Conclusions

Our findings provide novel insights into women’s experiences balancing a pregnancy at increased risk for preterm birth with employment obligations. While many women reported positive experiences, the most striking insights came from women who described negative situations that ranged from challenging to potentially unlawful. Many of the findings suggest profound misunderstandings likely exist at the patient, employer and clinical provider level about the laws surrounding employment in pregnancy, safe employment responsibilities during pregnancy, and the range of creative accommodations that often allow for continued workplace productivity even during high risk pregnancy.

Employer-Reported Access to Paid Parental Leave: A study of San Francisco's Paid Parental Leave Ordinance

A growing body of research finds that paid leave policies have significant population health benefits for workers and their families, but the lack of a national paid leave policy in the United States leaves most workers without access to any paid leave. In 2017 San Francisco implemented the nation's first fully paid leave policy, mandating that covered employers provide up to six weeks of leave to care for a new child. The objective of our study is to examine how the San Francisco Paid Parental Leave Ordinance (PPLO) affected paid leave access, including among workers in low-wage industries. Methods: We surveyed Bay Area employers in 2018, the year after PPLO took effect. We estimated difference-in-differences models of changes in access to paid leave before versus after implementation of the PPLO in San Francisco compared to surrounding counties. Results: Availability of paid leave in San Francisco firms increased from 45% in 2016 to 79% following implementation of the PPLO. This is significantly more (p < 0.05) than the increase from 32% to 47% in surrounding counties. Compliance was lowest (67%) among low-wage firms. We found minimal evidence of self-reported negative effects on employers. Overall, 82% of firms supported the PPLO. Conclusions: San Francisco's experience demonstrates the feasibility of using local policy to increase parental leave access.

•

San Francisco recently enacted the first fully paid parental leave policy in the U.S.

•

Access to paid leave increased in San Francisco relative to surrounding counties.

•

Compliance was lowest among low-wage employers.

•

Employers reported minimal negative impacts and high support for the policy.

Exercise during pregnancy: a comparative review of guidelines

Exercise during pregnancy may be beneficial provided that there are no contraindications. The aim of this study was to summarize and compare recommendations regarding exercise in pregnancy. Thus, a comparative descriptive review was conducted and included guidelines by the American College of Obstetricians and Gynecologists, the Society of Obstetricians and Gynaecologists of Canada and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists. All compared guidelines recommend that pregnant women without contraindications should undertake physical activities regularly, however, the type of workout performed should be adjusted based on the previous exercise experience and the physical condition of each pregnant woman. A variation among the reviewed guidelines was identified on appropriate and inappropriate activities and on indications to interrupt exercise. To summarize, the adoption of an international up-to-date consensus regarding appropriate exercise during pregnancy may be beneficial in ensuring the safety of the pregnant women while promoting their physical and mental health.

Occupational exposure to whole-body vibrations and pregnancy complications: a nationwide cohort study in Sweden

Objectives

Pregnancy complications are common contributors to perinatal mortality and morbidity. Still, the cause(s) of gestational hypertensive disorders and diabetes are largely unknown. Some occupational exposures have been inconsistently associated with pregnancy complications, but exposure to whole-body vibrations (WBV) has been largely overlooked even though it has been associated with adverse birth outcomes. Therefore, the aim was to assess whether occupational WBV exposure during pregnancy is associated with pregnancy complications in a nationwide, prospective cohort study.

Methods

The Fetal Air Pollution Exposure cohort was formed by merging multiple Swedish, national registers containing information on occupation during pregnancy and diagnosis codes, and includes all working women who gave birth between 1994 and 2014 (n=1 091 044). WBV exposure was derived from a job-exposure matrix and was divided into categories (0, 0.1–0.2, 0.3–0.4 and ≥0.5 m/s²). ORs with 95% CIs were calculated using logistic regression adjusted for potential confounders.

Results

Among women working full time (n=646 490), we found increased risks of all pregnancy complications in the highest exposure group (≥0.5 m/s²), compared with the lowest. The adjusted ORs were 1.76 (95% CI 1.41 to 2.20), 1.55 (95% CI 1.26 to 1.91) and 1.62 (95% CI 1.07 to 2.46) for preeclampsia, gestational hypertension and gestational diabetes, respectively, and were similar in all sensitivity analyses. There were no clear associations for part-time workers.

Conclusions

The results suggest that women should not be exposed to WBV at/above the action limit value of 0.5 m/s² (European directive) continuously through pregnancy. However, these results need further confirmation.

Associations between work environment, health status and sick leave among pregnant employees

Aims: To study the associations between and timing of psychosocial and physical work factors and health status on sick leave among Danish pregnant employees. Methods: A total of 910 pregnant women completed a questionnaire in gestational weeks 12 (baseline) and 27 (follow-up). Information about psychosocial and physical work factors and health status was obtained at baseline. Associations with sick leave ⩾14 days were estimated using logistic regression. Further, the impact of timing and duration of exposure on sick leave were examined. Results: A total of 133 women (14.6%) reported ⩾14 days of sick leave at follow-up (27 weeks of gestation). Work-related risk factors for sick leave were high work pace, low influence, low recognition, low job satisfaction, conflict in work−family balance, standing/walking, heavy lifting, and shift work/night shift. Health-related risk factors were burnout, stress, possibility of depression, low work ability, previous sick leave, and poor self-rated health. Being exposed to work-related risk factors during the first 27 weeks of pregnancy or at follow-up increased the risk of sick leave compared with those not exposed at any time or only exposed at baseline. Poor health status increased the risk if women were exposed in the first 27 weeks of pregnancy; however, high possibility of depression was also a risk factor when experienced in early pregnancy. Conclusions: Psychosocial and physical work-related risk factors and poor health status were associated with more sick leave in pregnant employees. Early adjustment of work-related risk factors at the workplace is needed to reduce sick leave.

Association between maternal shift work and infant neurodevelopmental outcomes: results from the Taiwan Birth Cohort Study with propensity-score-matching analysis

BACKGROUND

Maternal shift work is associated with preterm delivery, small-for-gestational-age new-borns, childhood obesity and future behavioural problems. However, the adverse effects on and interactions of maternal shift work with infant neurodevelopment remain uncertain. Therefore, we examined the associations between maternal-shift-work status and infant neurodevelopmental parameters.

METHODS

The Taiwan Birth Cohort Study is a nationwide birth cohort study following representatively sampled mother-infant pairs in 2005. The participants' development and exposure conditions were assessed by home interviews with structured questionnaires at 6 and 18 months of age. Propensity scores were calculated with predefined covariates for 1:1 matching. Multivariate conditional logistic regression and the Cox proportional-hazards model were used to examine the association between maternal-shift-work status and infant neurodevelopmental-milestone-achievement status.

RESULTS

In this study, 5637 term singletons were included, with 2098 cases selected in the propensity-score-matched subpopulation. Persistent maternal shift work was associated with increased risks of delays in gross-motor neurodevelopmental milestones [aOR = 1.36, 95% confidence interval (CI) = 1.06-1.76 for walking steadily], fine-motor neurodevelopmental milestones (aOR = 1.39, 95% CI = 1.07-1.80 for scribbling) and social neurodevelopmental milestones (aOR = 1.35, 95% CI = 1.03-1.76 for coming when called upon). Moreover, delayed gross-motor and social development were identified in the propensity-score-matched sub-cohort.

CONCLUSIONS

This study shows negative associations between maternal shift work and delayed neurodevelopmental-milestone achievement in the gross-motor, fine-motor and social domains at 18 months. Future research is necessary to elucidate the possible underlying mechanisms and long-term health effects.

Shift work and long work hours and their association with chronic health conditions: A systematic review of systematic reviews with meta-analyses

Background

Previous reviews have demonstrated that shift work and long work hours are associated with increased risk for chronic conditions. However, these reviews did not comprehensively assessed the body of evidence, and some were not conducted in a systematic manner. A better understanding of the health consequences of shift work and long work hours will aid in creating policy and practice recommendations. This review revisits the epidemiologic evidence on the association of shift work and long work hours with chronic conditions with particular emphasis on assessing the quality of the evidence.

Methods and findings

We conducted a systematic review of systematic reviews with meta-analyses (SR-MA) that assessed the link between shift work or long work hours and chronic conditions (PROSPERO CRD42019122084). We evaluated the risk of bias of each SR-MA using AMSTAR v2 and assessed the overall evidence for each condition using the GRADE approach. We included 48 reviews covering cancers, cardiovascular diseases, metabolic syndrome and related conditions, pregnancy complications, depression, hypertension, and injuries. On average, only 7 of 16 AMSTAR items were fulfilled. Few SR-MAs had a registered protocol and nearly all failed to conduct a comprehensive search. We found moderate grade evidence linking shift work to breast cancer and long work hours to stroke. We found low grade evidence linking both shift work and long work hours with low to moderate increase in risk for some pregnancy complications and cardiovascular diseases. Low grade evidence also link long work hours and depression.

Conclusions

Moderate grade evidence suggest that shift work and long work hours increase the risk of breast cancer and stroke, but the evidence is unclear on other chronic conditions. There is a need for high-quality studies to address this gap. Stakeholders should be made aware of these increased risks, and additional screening and prevention should be considered, particularly for workers susceptible to breast cancer and stroke.

Physical Activity and Exercise During Pregnancy and the Postpartum Period: ACOG Committee Opinion, Number 804

Exercise, defined as physical activity consisting of planned, structured, and repetitive bodily movements done to improve one or more components of physical fitness, is an essential element of a healthy lifestyle, and obstetrician-gynecologists and other obstetric care providers should encourage their patients to continue or to commence exercise as an important component of optimal health. Women who habitually engaged in vigorous-intensity aerobic activity or who were physically active before pregnancy can continue these activities during pregnancy and the postpartum period. Observational studies of women who exercise during pregnancy have shown benefits such as decreased gestational diabetes mellitus, cesarean birth and operative vaginal delivery, and postpartum recovery time. Physical activity also can be an essential factor in the prevention of depressive disorders of women in the postpartum period. Physical activity and exercise in pregnancy are associated with minimal risks and have been shown to benefit most women, although some modification to exercise routines may be necessary because of normal anatomic and physiologic changes and fetal requirements. In the absence of obstetric or medical complications or contraindications, physical activity in pregnancy is safe and desirable, and pregnant women should be encouraged to continue or to initiate safe physical activities. This document has been revised to incorporate recent evidence regarding the benefits and risks of physical activity and exercise during pregnancy and the postpartum period.

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.

Clock control of mammalian reproductive cycles: Looking beyond the pre-ovulatory surge of gonadotropins

Several aspects of the physiology and behavior of organisms are expressed rhythmically with a 24-h periodicity and hence called circadian rhythms. Such rhythms are thought to be an adaptive response that allows to anticipate cyclic events in the environment. In mammals, the circadian system is a hierarchically organized net of endogenous oscillators driven by the hypothalamic suprachiasmatic nucleus (SCN). This system is synchronized by the environment throughout afferent pathways and in turn it organizes the activity of tissues by means of humoral secretions and neuronal projections. It has been shown that reproductive cycles are regulated by the circadian system. In rodents, the lesion of the SCN results on alterations of the estrous cycle, sexual behavior, tonic and phasic secretion of gonadotropin releasing hormone (GnRH)/gonadotropins and in the failure of ovulation. Most of the studies regarding the circadian control of reproduction, in particular of ovulation, have only focused on the participation of the SCN in the triggering of the proestrus surge of gonadotropins. Here we review aspects of the evolution and organization of the circadian system with particular focus on its relationship with the reproductive cycle of laboratory rodents. Experimental evidence of circadian control of neuroendocrine events indispensable for ovulation that occur prior to proestrus are discussed. In order to offer a working model of the circadian regulation of reproduction, its participation on aspects ranging from gamete production, neuroendocrine regulation, sexual behavior, mating coordination, pregnancy and deliver of the product should be assessed experimentally.

The effect of prenatal maternity leave on short and long-term child outcomes

Maternity leave policies are designed to safeguard the health of pregnant workers and their unborn children. We evaluate a maternity leave extension in Austria which increased mandatory prenatal leave from 6 to 8 weeks. We exploit that the assignment to the extended leave was determined by a cutoff date. We find no evidence for significant effects of this extension on children's health at birth or long-term health and labor market outcomes. Subsequent maternal health and fertility are also unaffected. We conclude that employment during the 33rd and 34th week of gestation is not harmful for expecting mothers (without major problems in pregnancy) and their unborn children.

Gender inequity as a barrier to women's access to skilled pregnancy care in rural Nigeria: a qualitative study

BACKGROUND

Maternal mortality has been an issue of global importance, with continued efforts by the international development community towards its reduction. The provision of high quality maternal healthcare has been identified as a key strategy in preventing maternal mortality. Gendered intrahousehold power structures, gendered dynamics of resource allocation and women's limited ability in decision-making can have a huge impact on maternal health-seeking behaviour and overall health status. Using a gender lens, this study explores the root causes of women's limited access to and utilisation of maternal healthcare services in rural areas of Edo State, Nigeria.

METHODS

This qualitative study involved the analysis of data collected from gender- and age-desegregated focus group discussions (FDGs) in 20 communities in Etsako East and Esan South East local government areas of Edo State, Nigeria. Focus group participants comprised women between the ages of 15-45 y who have been pregnant within the last 5 y and their male spouses and partners of varying ages. A total of 20 FGDs were conducted. Coded transcripts were reviewed and analysed using the gender framework as an analytical guide.

RESULTS

Most responses indicated that women did not entirely have the power to make decisions regarding when to seek care during pregnancy. Women's experiences of access to quality care showed intersecting areas of gender and social economic status (SES) and how they impact on access to health. Many of the responses suggested high levels of economic marginalisation among women with women being financially dependent on their spouses and partners for pregnancy healthcare-related costs. Furthermore, a man's financial status determined the type of care his spouse or partner sought. Women identified a high workload as an issue during pregnancy and a barrier to accessing maternal healthcare services. The role of men within households was generally perceived as that of financial providers, therefore a husband's support was commonly constructed to solely mean financial support.

CONCLUSION

This paper brings attention to the role of gender and SES in producing and sustaining limitations to women's access to quality care. Interventions geared towards supporting women's financial independence is an important step towards improving their access to skilled healthcare, more so are interventions that improve women's decision-making capacities.

Retrospective cohort study of the association between maternal employment precarity and infant low birth weight in women in the USA

OBJECTIVES

To investigate the association between maternal employment precarity and infant low birth weight (LBW), and to assess if this association differs by race/ethnicity.

METHODS

Data were collected from 2871 women enrolled in the National Longitudinal Survey of Youth 1979 and the National Longitudinal Survey of Youth 1979 Children and Young Adult Cohort. Employment precarity was evaluated using a summary variable that combined several employment attributes: availability of employer-sponsored insurance, income, long shifts, non-daytime shifts, availability of employer sponsored training or educational benefits and membership in a union or collective bargaining unit. Employment precarity scores (a sum of the number of negative employment attributes) were categorised into low (0-2), medium (3) and high (4-6). LBW was defined as weight less than 2500 g at birth. Modified Poisson models were fit to calculate risk ratios and 95% CIs and adjusted for maternal age, race/ethnicity, educational attainment, nativity, prepregnancy body mass index, alcohol consumption, smoking during pregnancy and infant year of birth. We assessed effect modification by maternal race/ethnicity using a composite exposure-race variable.

RESULTS

Women with high employment precarity had higher risk of a LBW delivery compared with women with low employment precarity (RR: 1.48, 95% CI: 1.11 to 1.98). Compared to non-Hispanic/non-black women with low employment precarity, non-Hispanic black women (RR: 2.68; 95% CI: 1.72 to 4.15), Hispanic women (RR: 2.53; 95% CI: 1.54 to 4.16) and non-Hispanic/non-black women (RR: 1.46; 95% CI: 0.98 to 2.16) with high employment precarity had higher risk of LBW.

CONCLUSIONS

We observed higher risk of LBW in pregnancies of women with high employment precarity; this association was stronger among black and Hispanic mothers compared to non-Hispanic/non-black women. Findings of this study can be used to inform antenatal care and identify workplace policies to better support women who work during pregnancy.