Working conditions in women with multiple pregnancy-the impact on preterm birth and adherence to guidelines: a prospective cohort study.

BACKGROUND: Women with multiple pregnancies are at risk for maternal complications such as preterm birth. Hazardous working conditions, such as physically demanding work and long and irregular working hours, might increase the risk of preterm birth. OBJECTIVE: This study primarily aimed to determine whether certain working conditions up to 20 weeks of pregnancy increase the risk of preterm birth in multiple pregnancies. The secondary objective was to evaluate whether the working conditions of Dutch women with multiple pregnancy have been adjusted to the guidelines of the Netherlands Society of Occupational Medicine. STUDY DESIGN: We performed a prospective cohort study alongside the ProTWIN trial, a multicenter randomized controlled trial that assessed whether cervical pessaries could effectively prevent preterm birth. Women with paid work of >8 hours per week completed questionnaires concerning general health and working conditions between 16 and 20 weeks of pregnancy. Univariable and multivariable logistic regression analyses were performed to identify work-related factors associated with preterm birth (32-36 weeks' gestation) and very preterm birth (<32 weeks' gestation). We analyzed a subgroup of participants who worked for more than half of the week (>28 hours). We calculated the proportion of women who reported work-related factors not in accordance with guidelines. RESULTS: We studied 383 women, of whom 168 (44%) had been randomized to pessary, 142 (37%) to care as usual, and 73 (19%) did not participate in the randomized part of the study. After adjusting for confounding variables, working >28 hours was associated with very preterm birth (n=33; 78%) (adjusted odds ratio, 3.0; 95% confidence interval, 1.1-8.1), and irregular working times were associated with preterm birth (n=26, 17%) (adjusted odds ratio, 2.0; 95% confidence interval, 1.0-4.1) and very preterm birth (n=10; 24%) (adjusted odds ratio, 2.7; 95% confidence interval, 1.0-7.3). Within a subgroup of 213 participants working >28 hours per week, multivariable analysis showed that irregular working times (n=16; 20%) (adjusted odds ratio, 3.5; 95% confidence interval, 1.2-10.1) and no/little freedom in performance of tasks (n=23; 28%) (adjusted odds ratio, 3.0; 95% confidence interval, 1.3-7.3) were associated with preterm birth. Irregular working times (n=9; 27%) (adjusted odds ratio, 3.4; 95% confidence interval, 1.0-11.1), requiring physical strength (n=9; 27%) (adjusted odds ratio, 5.3; 95% confidence interval, 1.6-17.8), high physical workload (n=7; 21%) (adjusted odds ratio, 3.9; 95% confidence interval, 1.1-13.9), and no/little freedom in performing tasks (n=10; 30%) (adjusted odds ratio, 3.2; 95% confidence interval, 1.1-9.6) were associated with very preterm birth. Before 20 weeks of pregnancy, 224 (58.5%) women with multiple pregnancy continued to work under circumstances that were not in accordance with the guidelines. CONCLUSION: In our cohort study, nearly 60% of women with multiple pregnancy continued to work under circumstances not in accordance with the guidelines to avoid physical and job strain and long and irregular working hours. Irregular hours were associated with preterm and very preterm birth, and long hours were associated with preterm birth.

Working conditions in low risk nulliparous women in The Netherlands: are legislation and guidelines a guarantee for a healthy working environment? A cohort study.

OBJECTIVE: Hazardous working conditions increase the risk of adverse pregnancy outcomes. In this study, we examine adherence to legislation and guidelines aimed at improving working conditions in pregnancy. METHODS: Between 2014 and 2016, we recruited a prospective cohort of low-risk nulliparous pregnant women in paid employment or self-employed in 16 community midwifery practices in The Netherlands. Participants completed two questionnaires concerning demographics, education, general health and working conditions between 10-16 and 20-24 weeks of pregnancy. We calculated the proportion of participants with work-related risk factors not in accordance with legislation and/or guidelines. RESULTS: Of 269 participants included, 214 (80%) completed both questionnaires. At 10-16 weeks 110 (41%) participants and at 20-24 weeks 129 (63%) participants continued to work under circumstances that did not meet recommendations. Employers provided mandated information on work adjustment to 37 (15%) participants and 96 (38%) participants received no information about the potential hazards while working with biological and chemical hazards. Participants with lower educational attainment (aOR 2.2 95%CI 1.3-3.9), or employment in healthcare (aOR 4.5, 95%CI 2.2-9.0), education/childcare and social service (aOR 2.6, 95%CI 1.1-6.0 2),, catering (aOR 3.6, 95%CI 1.1-12) and industry, construction and cleaning (aOR 3.3, 95%CI 1.1-10.3) more often continued work which did not meet recommendations. CONCLUSION: There is poor adherence to national legislation and guidelines for safe working in pregnancy in The Netherlands: 50% of the pregnant women worked under hazardous conditions. Given the impact on adverse pregnancy outcomes as well as on the public purse, action to improve compliance must be taken by all stakeholders.

Risk factors for spontaneous preterm birth among healthy nulliparous pregnant women in the Netherlands, a prospective cohort study.

Introduction: Spontaneous preterm birth (sPTB) is a major contributor to neonatal morbidity and mortality worldwide. The pathophysiology of sPTB is poorly understood, in particular among nulliparous women without apparent medical or obstetric risk factors. Therefore, we aimed to identify risk factors for sPTB in healthy nulliparous women. Material and Methods: We performed a prospective cohort study. Recruitment took place from February 2014 to December 2016 in 16 community midwifery centers in the Netherlands. Eligibility criteria were: ≥18 years, no previous pregnancy >16 weeks of gestation, healthy singleton pregnancy, and antenatal booking <24 weeks of gestation. At study inclusion, participants completed a questionnaire, including details on lifestyle, work, and medical history. Cervical length was measured by vaginal ultrasound at the second-trimester anomaly scan. Detailed information concerning pregnancy and birth was collected via antenatal charts. We calculated the adjusted odds ratio (aOR) and 95% confidence intervals (CI) for various risk factors with correction for socioeconomic status (SES) using logistic regression and Firth's correction. Results: We included 363 women of whom pregnancy outcomes were available in 349 (96.1%) participants. The cervical length measurement was available for 225 (62.0%) participants. sPTB occurred in 26 women (7.5%). SES was associated with sPTB (OR: 3.7, 95%  CI: 1.6-8.5) in univariate analysis. First or second trimester vaginal bleeding (aOR: 3.6, 95% CI: 1.4-9.0) and urinary tract infection during pregnancy (aOR: 4.9, 95% CI: 1.7-13.9) were associated with sPTB in multivariate analysis. Conclusions: This prospective cohort confirms established risk factors for sPTB in nulliparous women deemed at low risk of sPTB.