Occupational predictors of pregnancy outcomes in Irish working women in the Lifeways cohort

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.

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].

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.

Greater Risk of Pregnancy Complications for Female Surgeons: A Cross-Sectional Electronic Survey

BACKGROUND

Female surgeons are exposed to physical and mental stressors that differ from those of other specialties. We aimed to assess whether female surgeons are more at risk of pregnancy complications than women in other medical specialties.

METHODS

We used a cross-sectional electronic survey of female physicians working in the French Region Nouvelle-Aquitaine who were pregnant between 2013 and 2018. A pregnancy complication was defined as the occurrence of miscarriage, ectopic pregnancy, fetal growth restriction, prematurity, fetal congenital malformation, stillbirth, or medical termination of the pregnancy. Multivariate logistic regression models were used to evaluate the risk of pregnancy complications for female surgeons relative to women practicing in other medical specialties.

RESULTS

Among the 270 women included, 52 (19.3%) experienced pregnancy complications and 28 (10.4%) were surgeons. In the multivariate analysis, female surgeons had a higher risk of pregnancy complications: adjusted odds ratio = 3.53, 95% confidence interval [1.27-9.84].

CONCLUSION

Further research is necessary to identify the hazards specifically involved in the practice of surgery to be able to propose preventive actions targeted to female surgeons during their pregnancy.

Neighborhood deprivation and preterm delivery during the coronavirus 2019 pandemic

BACKGROUND

Prior studies have reported decreases in the preterm delivery incidence during the COVID-19 pandemic. However, the findings are inconsistent. Given the wide disparities in the pandemic's impact across communities, neighborhood deprivation may explain the observed variation in the relationship between the COVID-19 pandemic and preterm delivery.

OBJECTIVE

To characterize the changes in the incidence of preterm delivery during the COVID-19 pandemic with attention to the effect modification introduced by neighborhood hardship.

STUDY DESIGN

This retrospective cohort study included all the pregnant patients who delivered at an urban tertiary care hospital during the pandemic (April–November 2020) or before the pandemic (April–November 2019). We compared the incidence of preterm delivery, spontaneous preterm delivery, and medically indicated preterm delivery before 37 weeks’ gestation across epochs. Planned analyses stratified the cohorts by neighborhood deprivation metrics defined by the residential zip code; the metrics included the median neighborhood household income and the hardship index (a composite index including dependency, educational attainment, unemployment, poverty, per capita income, and crowded housing). The Breslow-Day test for homogeneity assessed the association of the delivery epoch and neighborhood deprivation with the preterm delivery outcomes.

RESULTS

Of 16,544 eligible deliveries, 8.7% occurred preterm. The incidences of preterm delivery (8.4% vs 9.0%; P=.17), spontaneous preterm delivery (5.0 vs 5.4%; P=.27), and medically indicated preterm delivery (3.2% vs 3.5%; P=.47) were similar in the pandemic and prepandemic epochs. However, the preterm delivery (odds ratio, 0.78; 95% confidence interval, 0.64–0.96) and spontaneous preterm delivery (odds ratio, 0.76; 95% confidence interval, 0.59–0.99) decreased from the prepandemic to the pandemic epoch in those living in neighborhoods <50th percentile for median income (Breslow-Day P values.047 and.036, respectively). Similarly, the preterm delivery (odds ratio, 0.78; 95% confidence interval, 0.64–0.97) and spontaneous preterm delivery (odds ratio, 0.74; 95% confidence interval, 0.57–0.98) decreased for those inhabiting the neighborhoods in the highest-hardship quartile (Breslow-Day P values.045 and.029, respectively).

CONCLUSION

The populations residing in socioeconomically disadvantaged neighborhoods experienced reductions in preterm delivery during the COVID-19 pandemic. Neighborhood-level social determinants of health offer insight into the complex etiologies that contribute to preterm delivery and provide opportunities for public health and equity-focused prevention strategies.

Socioeconomic inequalities and adverse pregnancy outcomes in the UK and Republic of Ireland: a systematic review and meta-analysis

OBJECTIVE

There has been an unprecedented rise in infant mortality associated with deprivation in recent years in the United Kingdom (UK) and Republic of Ireland. A healthy pregnancy can have significant impacts on the life chances of children. The objective of this review was to understand the association between individual-level and household-level measures of socioeconomic status and adverse pregnancy outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Nine databases were searched (Medline, Embase, Scopus, ASSIA, CINAHL, PsycINFO, BNI, MIDRIS and Google Scholar) for articles published between 1999 and August 2019. Grey literature searches were also assessed.

STUDY SELECTION CRITERIA

Studies reporting associations between individual-level or household socioeconomic factors on pregnancy outcomes in the UK or Ireland.

RESULTS

Among the 82 353 search results, 53 821 titles were identified and 35 unique studies met the eligibility criteria. Outcomes reported were neonatal, perinatal and maternal mortality, preterm birth, birth weight and mode of delivery. Pooled effect sizes were calculated using random-effects meta-analysis. There were significantly increased odds of women from lower levels of occupation/social classes compared with the highest level having stillbirth (OR 1.40, 95% CI 1.23 to 1.59, I²98.62%), neonatal mortality (OR 1.39, 95% CI 1.22 to 1.57, I²97.09%), perinatal mortality (OR 1.39, 95% CI 1.23 to 1.57, I²98.69%), preterm birth (OR 1.41, 95% CI 1.33 to 1.50, I²70.97%) and low birth weight (OR 1.40, 95% CI 1.19 to 1.61, I²99.85%). Limitations relate to available data, unmeasured confounders and the small number of studies for some outcomes.

CONCLUSIONS

This review identified consistent evidence that lower occupational status, especially manual occupations and unemployment, were significantly associated with increased risk of multiple adverse pregnancy outcomes. Strategies to improve pregnancy outcomes should incorporate approaches that address wider determinants of health to provide women and families with the best chances of having a healthy pregnancy and baby and to decrease pregnancy-related health inequalities in the general population.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019140893.

Neonatal near misses and associated factors among mother's who give a live neonate at Hawassa City governmental hospitals, 2019: a facility based cross-sectional study design

BACKGROUND

Neonatal near miss is a neonate who nearly died but survived from a severe complication occurred during pregnancy, birth or within 0-28 days of extra-uterine life. However, there is no available data that quantifies the magnitude of neonatal near miss (NNM) in Ethiopia where there is high prevalence of neonatal mortality. Therefore, this study is designed to provide information about the magnitude and associated factors of neonatal near miss among women who give a live birth at Hawassa City Governmental hospitals, 2019.

METHODS

A facility based cross-sectional study design was conducted on 604 mothers who gave live neonates at Adare General Hospital and Hawassa University Comprehensive and Specialized Hospital from May 9, 2019 to June 7, 2019. Face to face interviewer administered structured questionnaire with a supplementation of maternal and neonatal medical records with checklists were used to collect the data. Data were coded and entered in to Epi data version 3.1 and then exported to the Statistical Package for Social Science IBM version 25 for analysis. Descriptive statistics was run and the data were presented using frequency tables and figure. The bi-variable and multivariable logistic regression was used to identify the possible factors of neonatal near miss. Finally, Adjusted Odds Ratio and 95% Confidence Intervals were used to declare statsticall significance.

RESULT

Among all 604 selected live births an overall proportion of NNM cases, 202 (33.4%) (95% CI: 29.7-37.1%) was obtained at Hawassa City Government Hospitals. Respiratory distress 158 (94%) and infection or sepsis 138 (84%) were found to be the leading causes of NNM cases in our study. Governmental and non-governmental employed mother (AOR = 3.05, 95% CI: 1.46-6.44) and Cesarean Section delivery (AOR = 1.89, (95% CI: 1.25-2.83)) were positively significantly associated with neonatal near miss. Whereas, pregnancy induced Hypertension (AOR = 0.43, 95%CI: 0.27-0.69) was negatively associated with neonatal near miss.

CONCLUSION

This study revealed relatively high prevalence of NNM in the study areas. Employed women, pregnancy induced hypertension and cesarean section mode of delivery were found to be independent factors affecting the prevalence of NNM cases. Therefore, HUCSH and Adare general Hospitals should focus on proving quality antenatal care and prevention of occupational related problems among pregnant women.

Structural Model of Maternal Behavior in Community Setting to Prevent Low Birth Weight in East Nusa Tenggara, Indonesia

Low birth weight (LBW) is still a magnitude problem in Indonesia with a multifactorial causes. Studies revealed that one of cause of LBW-infants birth is mother's behavior in treating her pregnancy, including traditional pregnancy care practices. The purpose was to develop the structural model on community setting that might describe the LBW infants-birth. A case-control study on 50 post-partum mothers with LBW and 50 with normal birthweight infants was held in Kupang, East Nusa Tenggara, Indonesia, November 2016 - May 2017. Mother who have spontaneous birth, singleton, and received integrated ANC were inlcuded. Several data such as maternal characteristics, pregnancy knowledge, perceived behavioral control (PBC), maternal health status, obedience to traditional pregnancy care, were collected using questionnaire and medical records tracing. Statistical analysis was performed using path analysis from SmartPLS 3.2.7 and considered significant path when the coefficients were not zero with P value <0.05. Outer and inner model analysis showed two significant paths, both are come from maternal characteristic that influence the LBW infants-birth through pregnancy knowledge (0.489, P=0.000) and PBC (0,425, P=0,000). In the first path, PBC affect maternal health status (0.217, P=0.021) which in turn will cause LBW (0.201, P=0.001). The second path, PBC affect the obedience to traditional pregnancy care (0.474, P=0.000) and then influence to LBW (0.316, P=0.000). As conclusion, maternal characteristics, pregnancy knowledge, PBC, maternal health status, and obedience to traditional pregnancy care are key points that might be used as a significant variables in preventing LBW-infants birth.

Shiftwork and Light at Night Negatively Impact Molecular and Endocrine Timekeeping in the Female Reproductive Axis in Humans and Rodents

Shiftwork, including work that takes place at night (nightshift) and/or rotates between day and nightshifts, plays an important role in our society, but is associated with decreased health, including reproductive dysfunction. One key factor in shiftwork, exposure to light at night, has been identified as a likely contributor to the underlying health risks associated with shiftwork. Light at night disrupts the behavioral and molecular circadian timekeeping system, which is important for coordinated timing of physiological processes, causing mistimed hormone release and impaired physiological functions. This review focuses on the impact of shiftwork on reproductive function and pregnancy in women and laboratory rodents and potential underlying molecular mechanisms. We summarize the negative impact of shiftwork on female fertility and compare these findings to studies in rodent models of light shifts. Light-shift rodent models recapitulate several aspects of reproductive dysfunction found in shift workers, and their comparison with human studies can enable a deeper understanding of physiological and hormonal responses to light shifts and the underlying molecular mechanisms that may lead to reproductive disruption in human shift workers. The contributions of human and rodent studies are essential to identify the origins of impaired fertility in women employed in shiftwork.

The effect of local unemployment on health: A longitudinal study of Irish mothers 2001-2011

The relationship between economic conditions and health is mixed, with some evidence from the most recent financial crisis finding a positive effect of periods of unemployment on heath behaviours. This study uses longitudinal data spanning the periods before, during and after the Irish crisis of 2007, to test the impact of economic expansion and contraction on mothers physical and mental health and health behaviours. Three waves of data from the Irish Lifeways Cohort Study for the period 2001-2011, and local area employment rates from the Irish Census, are used to capture the impact of a period of increased unemployment on health before, during and after the Irish recession, independent of individual employment status. The results from fixed effect linear probability models demonstrate that an additional unit of local area unemployment increases the probability of reporting poor self-rated health by 1-1.8 percentage points and of reporting poor mental well-being by 1.4 and 2.7 percentage points depending on the instrument used. There are decreases in the probability of consuming cigarettes by 3.3 percentage points, self-describing as a regular smoker by 2.9 percentage points and obesity by 0.9 percentage points. The probability of engaging in at least 20 minutes of strenuous or moderate exercise per week declines by 7.8 and 8.7 percentage points respectively, while the probability of engaging in at least 20 minutes of mild exercise rises by 10 percentage points. These results are largely consistent with the US literature, which is predominantly based on working men, thus demonstrating the universal impact of economic vulnerability on health.

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.

Circadian rhythm and its association with birth and infant outcomes: research protocol of a prospective cohort study

BACKGROUND

Circadian rhythm plays an important role as our internal body's clock that synchronizes behavior and physiology according to the external 24-h light-dark cycle. Past studies have associated disrupted circadian rhythm with higher risk of miscarriages, preterm birth and low birth weights. This paper described the protocol of a prospective cohort study which aims to determine the circadian rhythm in pregnant women, identify its association with maternal factors during pregnancy, gestational weight gain, birth and infant outcomes.

METHODS

Ten government maternal and child health clinics in Kuala Lumpur, Malaysia will be randomly selected. Sample size of 438 first-trimester pregnant women will be followed-up until the birth of their infant. Salivary melatonin and cortisol concentration among subsample will be determined using enzyme-linked immunosorbent assay. Data on sleep quality, psychological distress and morningness/eveningness chronotype of pregnant women will be collected using validated questionnaires. Pedometer will be used to measure 5-day physical activity data. Total gestational weight gain will be determined at the end of pregnancy. Utilization of 3-day food record is to capture meal timing and nutrient intake. All measurements will be done in 2nd and 3rd trimester. Birth outcomes will be collected through clinic records and Centers for Disease Control and Prevention (CDC) Neonatal questionnaire. Infants will be followed-up at 6 and 12 months old to obtain anthropometric measurements.

DISCUSSION

There is a growing recognition of the role of maternal circadian rhythm, which entrains fetal circadian rhythms that may subsequently have long-term health consequences. The present study will identify the effect of circadian rhythm on pregnancy outcomes and infant growth in the first year of life.

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.

Reproductive health problems among female shift workers: A qualitative study in Iran

BACKGROUND

Shift work (i.e. working between 18:00 and 07:00) is associated with sleeplessness and fatigue and hence, can cause female shift workers different health problems. This study aimed to explore reproductive health problems among female shift workers.

MATERIALS AND METHODS

This qualitative study was conducted in Amol and Babol cities, Iran, on 19 female shift workers with previous history of pregnancy and breastfeeding. Participants were selected purposively and with maximum variation respecting their age, work experience, educational level, and financial and employment status. Face-to-face semi-structured interviews were held for data collection and conventional qualitative content analysis was employed for data analysis.

RESULTS

Female shift workers' reproductive health problems were categorized into fourteen subcategories and the five main categories of conflict between pregnancy and shift work, breastfeeding-related challenges, impaired sexual relationships, childbearing limitations, and gynecological problems.

CONCLUSION

Impaired sexual problems are the most significant reproductive health problem among female shift workers. Their reproductive health can be promoted through periodical reproductive health assessments by midwives, reproductive health specialists, psychologists, and gynecologists.

Association between ambient particulate matter concentration and fetal growth restriction stratified by maternal employment

Background

Fetal growth has been known to be associated with particulate matter (PM) air pollution during gestation. Given that regular working may deviate outdoor air pollution exposure, the association between air pollution and fetal growth restriction can be different across maternal working status. This study was to assess possible effect modification by maternal employment in the association between exposure to PM during pregnancy and fetal growth restriction.

Methods

Using hourly PM less than or equal to 10 and 2.5 μm in diameter (PM₁₀ and PM_2.5) regulatory monitoring data for 2001–2012 and 2008–2012, respectively, and birth certificate data for 2002–2012, we computed maternal exposures with district-level averages of PM₁₀ and PM_2.5 during one year before birth, entire pregnancy, and the 1st, 2nd and 3rd trimesters. The outcomes of fetal growth restriction were assessed by small for gestational age (SGA, weighted <10th percentile in the same gestational age) as well as low birth weight (LBW, < 2.5 kg) at term. We performed logistic regression to examine the association between PM and each of fetal growth restriction outcomes adjusting for individual risk factors. For effect modification by maternal employment, we estimated adjusted odds ratio (OR) of SGA or LBW for interquartile (IQR) increases in PM₁₀ or PM_2.5 stratified by employed and non-employed mothers. We also computed relative excess risk due to interaction (RERI) to investigate additive interaction.

Results

Among 824,011 singleton term births, 34.0% (279,856) were employed and 66.0% (544,155) were non-employed mothers. Proportions of LBW were 1.5% in employed and 1.6% in non-employed (P < 0.001). SGA occurred in 12.7% of employed and 12.8% of non- employed (P = 0.124) mothers. For non-employed mothers, we observed increased odds of SGA per IQR increase in PM₁₀ for one year before birth (OR = 1.02, 95% confidence intervals (CI): 1.00–1.04, P = 0.028). ORs of SGA for full pregnancy period and the 3rd trimester were also positive but did not reach statistical significance. We did not observe positive association for PM_2.5. RERI was not significant both for PM₁₀ and PM_2.5.

Conclusions

We did not observe evidence of effect modification by maternal employment in the association between ambient PM and fetal growth restriction. Future studies using more refined exposure measures should confirm this finding.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2401-9) contains supplementary material, which is available to authorized users.

[Shift-workers and night-workers' health consequences: State of art and recommendations]

There are in France several millions of shift-workers and night-workers (20 to 25% of employees). These workers are therefore subject to variations in their working and rest schedules. These regular schedule changes are associated with repeated desynchronization of circadian biological clock. The negative impacts on sleep are insomnia, drowsiness, and reduced sleep time in 24hours. There is also a proven effect on the occurrence of a metabolic syndrome, with a likely effect on obesity, type 2 diabetes, blood pressure and coronary artery disease. There is a likely effect on the occurrence of cancer (including breast cancer). Night working is not recommended for pregnant women because of the risk of miscarriage, prematurity and intrauterine growth retardation.

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.

A Communicative Model of Mothers' Lifestyles During Pregnancy with Low Birth Weight Based on Social Determinants of Health: A Path Analysis

OBJECTIVES

Low birth weight (LBW) is one of the major health problems worldwide. It is important to identify the factors that play a role in the incidence of this adverse pregnancy outcome. This study aimed to develop a tool to measure mothers' lifestyles during pregnancy with a view to the effects of social determinants on health and develop a correlation model of mothers' lifestyles with LBW.

METHODS

This study was conducted using methodological and case-control designs in four stages by selecting 750 mothers with infants weighing less than 4000 g using multistage sampling. The questionnaire contained 160 items. Face, content, criterion, and construct validity were used to study the psychometrics of the instrument.

RESULTS

After psychometrics, 132 items were approved in six domains. Test results indicated the utility and the high fitness of the model and reasonable relationships adjusted for variables based on conceptual models. Based on the correlation model of lifestyle, occupation (-0.263) and social relationships (0.248) had the greatest overall effect on birth weight.

CONCLUSIONS

The review of lifestyle dimensions showed that all of the dimensions directly, indirectly, or both affected birth weight. Thus, given the importance and the role of lifestyle as a determinant affecting birth weight, attention, and training interventions are important to promote healthy lifestyles.

The Relationship between Maternal Employment Status and Pregnancy Outcomes

Background and Objectives:

Women comprise a large percentage of the workforce in industrial countries. In Europe and many other places in the world, women of reproductive age comprise a significant proportion of the workforce at the workplaces, and the rules and regulations require employers to evaluate and minimize health risks to pregnant women. In U.K, 70%, and in the United States 59% of women are employed. In Iran, 13% of women are employed, which comes down to less than 5% at Sistan& Baluchestan Province. Various studies have reported contradictory results about the effects of maternal employment tasks such as standing, repetitive bending, climbing stairs, and lifting heavy objects during pregnancy on fetal growth, preterm birth and other obstetric complications. Given the growing number of working women, and potential complications for mothers, the present study has conducted to investigate the relationship between maternal employment status and pregnancy outcomes in Zahedan city, Iran.

Materials and Methods:

This cross-sectional study was based on survey conducted on 227 women (121 housewives, and 106 employed women) attending health centers in 2014. Using purposive convenient sampling method, eligible pregnant mothers (with no chronic diseases, singleton pregnancy, gravida 1-3, and no addiction) were selected as study subjects. Data were collected and recorded through a researcher-made questionnaire and also from mothers’ medical records, including personal details, prenatal and labor complications, and infant’s details. Collected data were fed into the SPSS version 21(IBM Corp, USA).

Results:

Frequency of placental abruption was greater among housewives (P=0.02), and a significant relationship was found between employment status and lifting heavy objects, which was more frequent among housewives (P=0.01). Lifting heavy objects during pregnancy was only significantly related to reduced amniotic fluid (P=0.001) and low birth weight (P=0.01). Frequency of preterm labor was higher among housewives compared to employed women, but not significantly. Type of delivery was significantly related to employment, and employed mothers had more cesarean deliveries (P=0.0001).

Conclusion:

The results suggest more frequent lifting of heavy objects by housewives than by employed mothers, leading to increased complications such as reduced amniotic fluid, placental abruption, and low birth weight. Perhaps due to higher education levels, frequency of cesarean section and preterm labor was higher among employed mothers. However, employment alone does not predict pregnancy outcomes.

Changes in work behavior during pregnancy in rural Anhui, China from 2001-03 to 2009: a population based cross-sectional study

Background

In low- and middle-income countries, many women continue working later into pregnancy. In our recent study on some areas in rural China, most women stopped working already during the first trimester (≤3 months) of pregnancy. In this paper we aimed to explore whether stopping work during early pregnancy has changed over an 8 year period (between 2001–03 and 2009); we also studied whether the reasons for stopping work early were the same in the two time periods.

Methods

A population-based cross-sectional survey with a representative sample of new mothers was carried out in one rural county in Anhui Province in 2001–03 (N = 1479 respondents) and in two other rural counties in 2009 (N = 1574 respondents). Both surveys were used to evaluate prenatal care interventions not related to work behavior. The surveys targeted all women who had recently given birth. Multilevel logistic regression analysis was used to examine the determinants of work behavior in the two time periods.

Results

There was a big change in the working behavior between the two survey years: in the period 2001–03 6 % and in 2009, 53 % of pregnant women stopped working at ≤3 months (percentage change 839, 95 % CI −15.90 to 1694.49). In 2001–03, 30 % and in 2009, 23 % of pregnant women worked the same as before pregnancy (percentage change −22.30, 95 % CI −90.28 to 45.68). In both time periods women with two children were less likely to stop work at ≤3 months of pregnancy. Non-farmers were more likely in 2001–03 but less likely in 2009 to stop work at ≤3 months of pregnancy. Women with medium township-level income were more likely to maintain the same level of work as before pregnancy in 2001–03, while in 2009 women with high township-level income were less likely to work the same.

Conclusion

Stopping work very early during pregnancy appeared to have become very common from 2001–3 to 2009 in rural Anhui, China and was not explained by women’s background characteristics.

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.

Maternal bereavement and the risk of preterm delivery: the importance of gestational age and of the precursor of preterm birth

BACKGROUND

Maternal stress during pregnancy may increase the risk of preterm delivery (PD), but the associations between stress and subtypes of PD are not clear. We investigated maternal loss of a close relative and risks of very and moderately PD (<32 and 32-36 weeks, respectively) and spontaneous and medically indicated PD.

METHOD

We studied 4 940 764 live singleton births in Denmark (1978-2008) and Sweden (1973-2006). We retrieved information on death of women's family members (children, partner, siblings, parents), birth outcomes and maternal characteristics from nationwide registries.

RESULTS

Overall, the death of a close family member the year before pregnancy or in the first 36 weeks of pregnancy was associated with a 7% increased risk of PD [95% confidence interval (CI) 1.04-1.10]. The highest hazard ratios (HR) for PD were found for death of an older child [HR (95% CI) 1.20 (1.10-1.31)] and for death of a partner [HR (95% CI) 1.31 (1.03-1.66)]. These losses were associated with higher risks of very preterm [HR (95% CI) 1.61 (1.29-2.01) and 2.07 (1.15-3.74), respectively] than of moderately preterm [HR (95% CI) 1.14 (1.03-1.26) and 1.22 (0.94-1.58), respectively] delivery. There were no substantial differences in the association between death of a child or partner and the risk of spontaneous v. medically indicated PD.

CONCLUSIONS

Death of a close family member the year before or during pregnancy was associated with an increased risk of PD, especially very PD. Possible mechanisms include both spontaneous and medically indicated preterm birth.

Grandparental morbidity and mortality patterns are associated with infant birth weight in the Lifeways cross-generation cohort study 2001-2010

The association of infants' birth weight with maternal cardiovascular morbidity (CVD) and mortality substantiates the foetal origins hypothesis. Few studies to date have investigated grandparent-infant risk association. We prospectively examined this relationship in the Lifeways three-generation familial cohort, contrasting lineage and gender differences to understand mechanisms of intergenerational risk transmission. In 2001, a cohort of 1082 families was established at antenatal stage. A total of 539 families (n = 539 infants) had both a participating grandparent (n = 1054) and information on infants' gestational age. At baseline, grandparents provided their diagnosed CVD status and 79% also underwent a cardiovascular risk factors assessment. In 2005, general practitioners provided an update for 61% grandparents. In 2010, a search of civil register confirmed 77 grandparental deaths in 539 families. Grandchildren's birth weight and grandparental cardiovascular risk factors associations were examined with linear regressions. Grandparental CVD associations were analysed using ANCOVA. Cox proportional hazard ratios (HR) were calculated for all-cause mortality associations. Models were adjusted for infants', mothers' and grandparents' demographic, anthropometric and socio-behavioural characteristics, as appropriate. The paternal grandfathers' (PGF) systolic blood pressure (mmHg) [β (95% CI) = 6.6 (0.8 - 12.5); P = 0.03] and paternal grandmothers' serum triglycerides (mmol/l) [β (95% CI) = 78.8 (7.0 - 150.7); P = 0.03] were linearly predictive of infants' birth weight, which was not observed for maternal grandparents. Mean birth weight for infants of maternal grandmothers with diabetes {-272.7 [(-499.7) - (-45.6)] g; P = 0.02} or stroke {-292.1 [(-544.5) - (-39.6)] g; P = 0.02} was lower than those without diabetes or stroke, a pattern not observed for paternal grandparents. Whereas PGFs' mortality was significantly associated with infants' high birth weight (≥4000 g) [HR (95% CI) = 4.9 (1.2 - 19.9); P = 0.03], maternal grandparents' mortality showed a converse pattern with infants' low birth weight (<2500 g) [HR (95% CI) = 1.7 (0.4 - 8.2); P = 0.7], although not statistically significant. These findings suggest that intergenerational transmission of risk differs in maternal and paternal lines.

Reproductive disorders in hairdressers and cosmetologists: a meta-analytical approach

OBJECTIVES

The aim of this study was to perform a systematic review and to use a meta-analytical approach to assess quantitatively the risk of adverse pregnancy outcomes in hairdressers and cosmetologists.

METHODS

A systematic literature search up to 1 February 2012 was carried out using major bibliographic databases, grey literature, contacts with research teams working on the subject, review papers and reference lists of selected articles. Observational studies reporting measures of effects in relation with body care (hairdressers, cosmetologists, etc.) and reproductive disorders were included. Study quality was assessed by three reviewers. The estimated risk ratios (RR) from all studies reporting on identical outcomes were combined using an average of logarithm transformation of estimated RR weighted by their inverted variance. Statistical heterogeneity across studies was assessed using Cochran's Q test. To explore the sources of heterogeneity, several sensitivity analyses and subgroup analyses were conducted based on study quality, country, study period, alcohol consumption, smoking habit, jobs and control populations.

RESULTS

Nineteen studies were selected and reviewed in-depth. The combined risk ratios (RRcs) of five reproductive outcomes were calculated and found to be significantly increased for four outcomes: time to pregnancy, which had an RRc of 1.11 (95% CI: 1.03-1.19); premature birth, which had an RRc of 1.05 (95% CI: 0.99-1.11); small for gestational age, which had an RRc of 1.24 (95 CI%: 1.10-1.41); low birth weight, which had an RRc of 1.21 (95% CI: 1.06-1.39); and embryonic and fetal losses, which had an RRc of 1.19 (95% CI: 1.03-1.38).

CONCLUSIONS

This work confirms a weak increase in risk of some reproductive disorders in female hairdressers/cosmetologists. However, the evidence level is rather weak, and a causal association between job and reproductive outcomes cannot be asserted.

Effect of maternal job strain during pregnancy on infant neurodevelopment by gender at 6 and 12 months: Mothers and Children's Environmental Health (MOCEH) study

OBJECTIVES

Limited evidence is available regarding the association between prenatal job strain and infant neurodevelopment. Most studies used stress indicators other than job strain to explain the relationship between prenatal maternal stress and child development. The objective of this study was to investigate the association between maternal job strain during pregnancy and neurodevelopment in infancy.

METHODS

Mothers and Children's Environmental Health (MOCEH) study, an on-going prospective birth cohort study, has been conducted in South Korea since 2006. Job strain during pregnancy was measured using Korean version of Job Content Questionnaire (JCQ). Infant neurodevelopment was assessed using Korean Bayley Scale of Infant Development II (K-BSID-II) at 6 and 12 months of age. A total of 343 mother-child pairs that completed JCQ and K-BSID-II more than once were included. Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) defined in the K-BSID-II were used as outcome variables.

RESULTS

Compared to infants from mothers with low job strain, significant (p < 0.05) decreases in PDI were found in infants from mothers with active and passive job at 6 months of age. After stratification by infant sex, boys in the high strain group had a lower MDI score than boys in the low job strain group at 12 months. On the other hand, girls in the high strain and active groups had higher MDI scores than girls in the low job strain group at 12 months. PDI at 12 months also showed different results by sex. Boys in the high strain and passive job groups had lower PDI scores than boys in the low job strain group. However, such difference was not observed in girls.

CONCLUSIONS

The findings of this study suggest that prenatal job strain affects infant neurodevelopment in a gender-dependent manner.

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.

Job strain and psychological distress among employed pregnant Thai women: role of social support and coping strategies

Most Thai women continue to work throughout their pregnancy; however, little is known about job strain and its relation to psychological distress. This study aimed to examine: (1) the direct effects of job strain, perceived workplace support, perceived family support, and coping strategies on psychological distress and (2) the moderating effect of perceived workplace support, perceived family support, and coping strategies on the relationship between job strain and psychological distress. Lazarus and Folkman's transactional model of stress and coping guided this cross-sectional study. Full-time employed pregnant women (N = 300) were recruited from three antenatal clinics in Thailand. Thai versions of the following instruments were used: the State-Anxiety Inventory and Center for Epidemiological Studies-Depression Scale (psychological distress), the Job Content Questionnaire (job strain and perceived workplace support), the Medical Outcome Study Social Support Survey (perceived family support), and the Ways of Coping Checklist-Revised (coping strategies). Job strain with other predictors explained 54% of the variance in psychological distress. In the separate hierarchical multiple linear regression models, two types of coping strategies, seeking social support and wishful thinking, moderated the effects of job strain on psychological distress. Perceived family support had a direct effect in reducing psychological distress. Job strain is a significant contributor to psychological distress. The average levels of seeking social support and wishful thinking were most beneficial in moderating the negative impact of job strain on psychological distress. Since perceived workplace and family support did not have moderating effects, stress management programs for decreasing the levels of job strain should be developed.

Preschoolers' parent-rated health disparities are strongly associated with measures of adiposity in the Lifeways cohort study children

OBJECTIVE

To examine the relationship between lifecourse factors from preschoolers' microecosystem and their parent-reported (mother-reported) health (PRH), following them prospectively from preconception to age 5 years. To investigate if preschoolers' body mass index (BMI) and waist circumference were associated with preschoolers' PRH when controlled for lifecourse predictors.

DESIGN

Lifeways cross-generation cohort study.

SETTING

Ireland.

PARTICIPANTS

Of 1082 families, 62% mothers responded on a health and lifestyle questionnaire at follow-up. Food frequency, BMI and waist circumference were measured. There were 547 family data sets available for analysis of children's PRH.

MAIN OUTCOME MEASURE

Mother-reported children's PRH at age 5. Associations with child's individual and familial exposures from preconception to age 5 years examined using logistic regression.

RESULTS

In univariate analysis, relatively positive rating of children's PRH were associated with children's lower intake of fats (OR (95% CI) 2.2 (1.1 to 4.3)), higher intake of fruits/vegetables (OR (95% CI) 2.2 (1.1 to 4.3)); as well as familial socioeconomic characteristics {higher household income (OR (95% CI) 3.0 (1.6 to 5.9)), non-entitlement to means-tested healthcare (OR (95% CI) 2.1 (1.0 to 4.3)), mothers' higher education (OR (95% CI) 1.9 (1.0 to 3.6))}, psychosocial characteristics {father's participation in study (OR (95% CI) 2.1 (1.0 to 4.3)), mothers' perceiving better support from partner (OR (95% CI) 2.3 (1.2 to 4.3)), children (OR (95% CI) 1.9 (1.0 to 3.7)) or relatives (OR (95% CI) 2.2 (1.1 to 4.1))}, parents' lifestyle {mothers' lower intake of energy (OR (95% CI) 2.2 (1.1 to 4.3)), fathers' non-smoking status (OR (95% CI) 2.2 (1.1 to 4.4))} and parents' health {mothers' self-rated health relatively positive (OR (95% CI) 5.1 (2.6 to 9.9)), fathers' self-rated health relatively positive (OR (95% CI) 3.0 (1.5 to 6.0))}. In multivariable analysis (χ(2)=34.2, df=21, N=303, R(2 )= 0.26, p<0.05), one of the two strong predictors of children's relatively positive PRH was child not being obese by International Obesity Task Force classification (OR (95% CI) 5.5 (1.4 to 21.0)), observed also using BMI (kg/m(2); OR (95% CI) 0.73 (0.58 to 0.93)) or waist circumference (cm; OR (95% CI) 0.89 (0.81 to 0.98)) as continuous variables. The other significant predictor was mothers' self-rated health relatively positive (OR (95% CI) 4.2 (1.5 to 12.2)).

CONCLUSIONS

Preschoolers' health is adversely associated with obesity and this is independent of lifecourse and social and environmental inequalities. The findings suggest that reducing childhood obesity and improving maternal health may be useful ways to improve child's global health.

Physically demanding work and preterm delivery: a systematic review and meta-analysis

OBJECTIVE

Physically demanding work may increase the risk of preterm delivery (PTD), defined as delivery before 37 weeks. We assessed the available evidence.

METHODS

A systematic search in Medline, Embase and Nioshtic for the period 1990 to June 2012 for observational and intervention studies on physically demanding work (prolonged standing, heavy lifting, physical exertion, occupational fatigue and demanding posture) and PTD. Selected studies were assessed for their risk of bias and pooled using a random effects model. Results of case-control and cohort studies were reported separately in subgroups.

RESULTS

We found 10 studies with low risk of bias and seven studies with moderate risk of bias. Standing and walking at work during pregnancy for more than 3 h per day was associated with an increased risk for PTD [OR 1.3 (95% CI 1.1-1.6)], just as lifting and carrying >5 kg [OR 1.3 (95% CI 1.05-1.6)] or lifting and carrying in the third trimester of the pregnancy [OR 1.3 (95% CI 1.01-1.8)]. Jobs that required physical effort or physical exertion were associated with an increased risk of PTD [OR 1.4 (95% CI 1.19-1.66)]. Working during pregnancy in jobs with a combination of two or more physical tasks, physical effort or occupational fatigue was also associated with an increased risk of PTD [OR 1.5 (95% CI 1.1-2.0)].

CONCLUSIONS

Physically demanding work during pregnancy is associated with an increased risk of PTD, especially in jobs with a combination of tasks with physical effort. In general, only small to moderate elevations of risks were found.

Longitudinal follow-up of the relationship between dietary intake and growth and development in the Lifeways cross-generation cohort study 2001-2013

In this paper we will review evidence on the early life and familial influences on childhood growth and development, with particular reference to the Lifeways cross-generation cohort study in the Republic of Ireland. The Lifeways cross-generation cohort study was established in 2001-2013 through two maternity hospitals in the Republic of Ireland and was one of many new cohort studies established worldwide in the millennium period. Mothers were recruited at first booking visit, completing a self-administered questionnaire, which included a 147 item semi-quantitative FFQ. Longitudinal follow-up is ongoing in 2013, with linkage data to hospital and general practice records and examination of children when aged 5 and 9 years. The study is one of very few containing data on grandparents of both lineages with at least one grandparent recruited at baseline. There have been consistent associations between parental and grandparental health status characteristics and children's outcomes, including infant birth-weight, BMI when child was aged 5 years and childhood wheeze or asthma when child was aged 3 and aged 5 years. In conclusion, empirical evidence to date shows consistent familial and cross-generational patterns, particularly in the maternal line.

Working conditions, socioeconomic factors and low birth weight: path analysis

Background

In recent years, with socioeconomic changes in the society, the presence of women in the workplace is inevitable. The differences in working condition, especially for pregnant women, has adverse consequences like low birth weight.

Objectives

This study was conducted with the aim to model the relationship between working conditions, socioeconomic factors, and birth weight.

Patients and Methods

This study was conducted in case-control design. The control group consisted of 500 women with normal weight babies, and the case group, 250 women with low weight babies from selected hospitals in Tehran. Data were collected using a researcher-made questionnaire to determine mothers’ lifestyle during pregnancy with low birth weight with health-affecting social determinants approach. This questionnaire investigated women’s occupational lifestyle in terms of working conditions, activities, and job satisfaction. Data were analyzed with SPSS-16 and Lisrel-8.8 software using statistical path analysis.

Results

The final path model fitted well (CFI =1, RMSEA=0.00) and showed that among direct paths, working condition (β=-0.032), among indirect paths, household income (β=-0.42), and in the overall effect, unemployed spouse (β=-0.1828) had the most effects on the low birth weight. Negative coefficients indicate decreasing effect on birth weight.

Conclusions

Based on the path analysis model, working condition and socioeconomic status directly and indirectly influence birth weight. Thus, as well as attention to treatment and health care (biological aspect), special attention must also be paid to mothers’ socioeconomic factors.

Multiple pregnancy, short cervix, part-time worker, steroid use, low educational level and male fetus are risk factors for preterm birth in Japan: a multicenter, prospective study

AIM

To examine the relationship between preterm birth and socioeconomic factors, past history, cervical length, cervical interleukin-8, bacterial vaginosis, underlying diseases, use of medication, employment status, sex of the fetus and multiple pregnancy.

METHODS

In a multicenter, prospective, observational study, 1810 Japanese women registering their future delivery were enrolled at 8⁺⁰ to 12⁺⁶ weeks of gestation. Data on cervical length and delivery were obtained from 1365 pregnant women. Multivariate logistic regression analysis was performed.

RESULTS

Short cervical length, steroid use, multiple pregnancy and male fetus were risk factors for preterm birth before 34 weeks of gestation. Multiple pregnancy, low educational level, short cervical length and part-timer were risk factors for preterm birth before 37 weeks of gestation.

CONCLUSION

Multiple pregnancy and cervical shortening at 20-24 weeks of gestation was a stronger risk factor for preterm birth. Any pregnant woman being part-time employee or low educational level, having a male fetus and requiring steroid treatment should be watched for the development of preterm birth.

Physical Activity Pattern and Personal-Social Factors of Mothers During Pregnancy And Infant Birth Weight Based On MET Scale: A Case-Control Study

Background

Low birth weight is one of the most important public health issues in developing and developed countries and identifying its etiology is important for prevention.

Objectives

Considering the unknown impact of physical activity on low birth weight, this research was conducted to investigate the relationship between physical activity and low birth weight.

Patients and Methods

This research was conducted using a case-control design. The control group was made of 500 women with normal birth weight infants and the case group included 250 women with low birth weight infants from the selected hospitals in city of Tehran. The information was gathered using a researcher-made questionnaire which was prepared for determining the relationship between mothers’ lifestyle during pregnancy and infants' low birth weight using social determinants of health approach. In this questionnaire, scope of physical activity was investigated in three groups of athletic activities, activities at home and leisure activities. Activity intensity was determined using MET scale and the data were analyzed in SPSS software using independent t-test, Chi-square and logistic regression.

Results

In the present research, based on the results of multiple logistic regression test, an increase in the time spent on sport activities (OR = 2.20) and home activities (OR =1.44) (P = 0.003) was accompanied by increased chance of giving birth to low birth weight infants; in contrast, one hour increase of leisure activities decreased the probability of low birth weight infants by 0.32 (P = 0.008).

Conclusions

An increase in the time spent on sport and home activities, even after considering other influential factors, was related to low birth weight.

Maternal education level and low birth weight: a meta-analysis

OBJECTIVE

To assess the association between maternal education level and birth weight, considering the circumstances in which the excess use of technology in healthcare, as well as the scarcity of these resources, may result in similar outcomes.

METHODS

A meta-analysis of cohort and cross-sectional studies was performed; the studies were selected by systematic review in the MEDLINE database using the following Key**words socioeconomic factors, infant, low birth weight, cohort studies, cross-sectional studies. The summary measures of effect were obtained by random effect model, and its results were obtained through forest plot graphs. The publication bias was assessed by Egger's test, and the Newcastle-Ottawa scale was used to assess study quality.

RESULTS

The initial search found 729 articles. Of these, 594 were excluded after reading the title and abstract; 21, after consensus meetings among the three reviewers; 102, after reading the full text; and three for not having the proper outcome. Of the nine final articles, 88.8% had quality ≥ six stars (Newcastle-Ottawa Scale), showing good quality studies. The heterogeneity of the articles was considered moderate. High maternal education showed a 33% protective effect against low birth weight, whereas medium degree of education showed no significant protection when compared to low maternal education.

CONCLUSIONS

The hypothesis of similarity between the extreme degrees of social distribution, translated by maternal education level in relation to the proportion of low birth weight, was not confirmed.

Does the developmental plasticity hypothesis have application to Irish Travellers? Findings from the all Ireland Traveller Health Study birth cohort 2008–2011

There is little record of birth weight of Irish Travellers, a minority group in Ireland. Travellers are known to have higher rate of adult chronic disease and to be exposed to life-long disadvantage. The aim of this study was to establish whether the birth weight and infant mortality rate patterns in Ireland's Travellers were consistent with the developmental plasticity hypothesis. A 1-year follow-up birth cohort study was conducted with linkage data from maternity hospital records of Traveller infants born on the island of Ireland over a 12-month period to self-identifying Traveller and general Irish population mothers from the Lifeways Cross-Generation Cohort Study. The main outcome measure was the rate of birth weight <3000 g in a cohort of Traveller children. There were 987 confirmed Traveller births, 500 of whose mothers consented to linkage to their records. A social gradient was observed in the distribution of birth weight in the general population and Traveller infants constituted the highest proportion of all social classes in the birth weight range of 3 kg or less (16.3%). There was a high rate of persistent smoking among Traveller mothers (53%). After adjustment for smoking and alcohol consumption in pregnancy, the birth weight differential persisted (OR 3.5, 95% CI 1.4–8.1). Infant mortality rate at 12.0/1000 births (95% CI 5.5–19.7) was almost four times that of the general population. This analysis confirms Travellers had a greater than expected incidence of low birth weight and high infant mortality with high rates of premature adult chronic diseases from all causes already demonstrated previously.

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

OBJECTIVES

We assessed the evidence relating preterm delivery (PTD), low birth weight, small for gestational age (SGA), pre-eclampsia and gestational hypertension to five occupational exposures (working hours, shift work, lifting, standing and physical workload). We conducted a systematic search in Medline and Embase (1966 to 2011), updating a previous search with a further 6 years of observations.

METHODS

As before, combinations of keywords and medical subject headings were used. Each relevant paper was assessed for completeness of reporting and potential for important bias or confounding, and its effect estimates abstracted. Where similar definitions of exposure and outcome existed we calculated pooled estimates of relative risk (RR) in meta-analysis.

RESULTS

Analysis was based on 86 reports (32 cohort investigations, 57 with usable data on PTD, 54 on birth weight and 11 on pre-eclampsia/gestational hypertension); 33 reports were new to this review. For PTD, findings across a substantial evidence base were generally consistent, effectively ruling out large effects (eg, RR>1.2). Larger and higher quality studies were less positive, while meta-estimates of risk were smaller than in previous analyses and best estimates pointed to modest or null effects (RR 1.04 to 1.18). For SGA, the position was similar but meta-estimates were even closer to the null (eight of nine RRs ≤ 1.07). For pre-eclampsia/gestational hypertension the evidence base remains insufficient.

CONCLUSIONS

The balance of evidence is against large effects for the associations investigated. As the evidence base has grown, estimates of risk in relation to these outcomes have become smaller.

Unmetabolized folic acid prevalence is widespread in the older Irish population despite the lack of a mandatory fortification program

BACKGROUND

In 2006 the Food Safety Authority of Ireland recommended mandatory folic acid fortification of flour for the prevention of neural tube defects in addition to the existing extensive voluntary folic acid fortification culture in place there. This recommendation is now suspended until further scientific evidence surrounding safety becomes available. The safety issues include concerns about the masking of vitamin B-12 deficiency and potential cancer acceleration, both of which may be of concern for the elderly population.

OBJECTIVE

The aim of this study was to measure the basal (fasted) concentrations of unmetabolized folic acid in the plasma of an elderly population group exposed to this liberal voluntary fortification of foodstuffs in Ireland.

DESIGN

We invited participants aged 60-86 y from the Lifeways Cross-Generation Cohort Study to participate in this project. After providing informed consent, the participants were invited to provide fasting blood samples and to complete a standard food-frequency questionnaire and a questionnaire on recent and habitual intakes of folic acid. Samples were assayed for total plasma folate, red blood cell folate, homocysteine, and unmetabolized folic acid.

RESULTS

A total of 137 subjects with a mean age of 67.4 y were studied. Unmetabolized folic acid was detected in 94.1% of the cohort with a mean concentration of 0.39 nmol/L (range: 0.07-1.59 nmol/L), accounting for 1.3% of total plasma folate.

CONCLUSION

These results indicate unmetabolized folic acid in plasma in most of this elderly Irish cohort, even after an overnight fast. These results should be considered carefully by those legislating in this area.

Familial intergenerational and maternal aggregation patterns in nutrient intakes in the Lifeways Cross-Generation Cohort Study

OBJECTIVE

The current study prospectively examines the intra-uterine hypothesis by comparing maternal, paternal and grandparental lineage influences on children’s diet and also maternal–child aggregation patterns during pregnancy and early childhood.

DESIGN

Prenatal dietary information was available for expectant mothers, fathers and up to four grandparents through a detailed validated semi-quantitative FFQ. At 6-year follow-up, when children averaged 5 years of age, dietary information was re-collected for mothers and a subset of maternal grandmothers using the same FFQ. Child’s FFQ version was used for children. Anthropometric and sociodemographic variables were also collected.

SETTINGS

Three-generation familial cohort representative of the contemporary Irish national population.

SUBJECTS

Children aged 5 years (n 567) and their parents and grandparents.

RESULTS

Associations for energy, macronutrient and fibre intakes were compared using Pearson’s correlations, intra-class correlations (ICC) and linear regression models, adjusted for energy and potential confounders. Significant, moderatestrength positive correlations were observed for nutrient intakes in children’s nuclear families (ICC (range)50?22–0?28). The father–child associations (r (range)5 0?13–0?20) were weaker than the mother–child associations (r (range)50?14–0?33). In general, associations were stronger for maternal postnatal intake–child intake than for maternal prenatal intake–child intake, except for percentage of energy from fat (adjusted b50?16, 95% CI 0?05, 0?26; P50?004), which was stronger for maternal prenatal intake, specifically in non-breast-fed children (adjusted b50?28, 95% CI 0?12, 0?44; P50?001). Among all grandparents, correlations were significant only for maternal grandmother–mother pairs (r (range)50?10–0?36). Significant positive ICC were observed for nutrient intakes of maternal grandmother–mother–child triads (ICC (range)50?12–0?27), not found in paternal lines.

CONCLUSIONS

These findings suggest that maternal-environment programming influences dietary intake.

Return to military weight standards after pregnancy in active duty working women: comparison of marine corps vs. navy

OBJECTIVE

To compare the likelihood of being within weight standards before and after pregnancy between United States Marine Corps (USMC) and Navy (USN) active duty women (ADW).

METHODS

ADW with singleton gestations who delivered at a USMC base were followed for 6 months to determine likelihood of returning to military weight standards. Odds ratio (OR), adjusted odds ratio (AOR) and 95% confidence intervals were calculated; p < 0.05 was considered significant.

RESULTS

Similar proportions of USN and USMC ADW were within body weight standards one year prior to pregnancy (79%, 97%) and at first prenatal visit (69%, 96%), respectively. However, USMC ADW were significantly more likely to be within body weight standards at 3 months (AOR 4.30,1.28-14.43) and 6 months after delivery (AOR 9.94, 1.53-64.52) than USN ADW. Weight gained during pregnancy did not differ significantly for the two groups (40.4 lbs vs 44.2 lbs, p = 0.163). The likelihood of spontaneous vaginal delivery was significantly higher (OR 2.52, 1.20-5.27) and the mean birth weight was significantly lower (p = 0.0036) among USMC ADW as compared to USN ADW.

CONCLUSIONS

Being within weight standards differs significantly for USMC and USN ADW after pregnancy.

Body mass index and height over three generations: evidence from the Lifeways cross-generational cohort study

Background

Obesity and its measure of body mass index are strongly determined by parental body size. Debate continues as to whether both parents contribute equally to offspring body mass which is key to understanding the aetiology of the disease. The aim of this study was to use cohort data from three generations of one family to examine the relative maternal and paternal associations with offspring body mass index and how these associations compare with family height to demonstrate evidence of genetic or environmental cross-generational transmission.

Methods

669 of 1082 families were followed up in 2007/8 as part of the Lifeways study, a prospective observational cross-generation linkage cohort. Height and weight were measured in 529 Irish children aged 5 to 7 years and were self-reported by parents and grandparents. All adults provided information on self-rated health, education status, and indicators of income, diet and physical activity. Associations between the weight, height, and body mass index of family members were examined with mixed models and heritability estimates computed using linear regression analysis.

Results

Self-rated health was associated with lower BMI for all family members, as was age for children. When these effects were accounted for evidence of familial associations of BMI from one generation to the next was more apparent in the maternal line. Heritability estimates were higher (h² = 0.40) for mother-offspring pairs compared to father-offspring pairs (h² = 0.22). In the previous generation, estimates were higher between mothers-parents (h² = 0.54-0.60) but not between fathers-parents (h² = -0.04-0.17). Correlations between mother and offspring across two generations remained significant when modelled with fixed variables of socioeconomic status, health, and lifestyle. A similar analysis of height showed strong familial associations from maternal and paternal lines across each generation.

Conclusions

This is the first family cohort study to report an enduring association between mother and offspring BMI over three generations. The evidence of BMI transmission over three generations through the maternal line in an observational study corroborates the findings of animal studies. A more detailed analysis of geno and phenotypic data over three generations is warranted to understand the nature of this maternal-offspring relationship.

Preterm birth during an extreme weather event in Québec, Canada: a "natural experiment"

To clarify the relationship between preterm birth (PTB) and extreme weather events, we evaluated PTB during a January 1998 ice storm that had led to a provincial emergency in the middle of winter in the province of Québec, Canada. Singleton live births for three periods (1993-1997, 1998, 1999-2003) were obtained (N = 855,320). PTB was defined as gestational age <37 completed weeks. Births in the Triangle of Darkness, the area most strongly affect by the storm, were geocoded. Multivariate logistic regression was used to calculate the likelihood of PTB for the Triangle relative to metropolitan Montréal, adjusting for maternal age, education, civil status, maternal birthplace, and previous deliveries. Associations for 1998 relative to other periods were evaluated. Short-term (January-February) and long-term (March-October) exposure periods were examined. The proportion PTB for 1998 January-February births in the Triangle (8.7%) was high compared with 1998 March-October births (6.0%) and with the corresponding proportions for 1993-1997 (6.2%) and 1999-2003 (6.9%). Covariate-adjusted odds of PTB for January-February 1998 were 27% higher for the Triangle relative to metropolitan Montréal, though precision was low. Furthermore, adjusted odds were 28% higher for 1998 relative to 1999-2003, despite increasing rates of PTB over time. Odds were not elevated over a long-term exposure period. This study suggests a weak association between PTB and exposure to extreme weather for the two months following an ice storm, but not for later periods after the storm.

Relationship between handling heavy items during pregnancy and spontaneous abortion: a cross-sectional survey of working women in South Korea

The researchers conducted a cross-sectional survey to determine the relationship between handling heavy items during pregnancy and spontaneous abortion among working women in South Korea. One thousand working women were selected from a database of those eligible for maternity benefits under the National Employment Insurance Plan. Study results showed that handling heavy items during pregnancy was associated with an increased risk of spontaneous abortion after adjusting for general characteristics of the participants and their work environment. A collective effort is needed on the parts of employers, employees, occupational health nurses, and the government to protect working women from lifting heavy items while pregnant.