Maternal occupation during pregnancy, birth weight, and length of gestation: combined analysis of 13 European birth cohorts

Research output: Contribution to journalJournal articleResearchpeer-review

  • Maribel Casas
  • Sylvaine Cordier
  • David Martínez
  • Henrique Barros
  • Alex Burdorf
  • Nathalie Costet
  • Ana Cristina Dos Santos
  • Asta Danileviciute
  • Merete Eggesbø
  • Mariana Fernandez
  • Joelle Fevotte
  • Ana M García
  • Regina Gražuleviciene
  • Eva Hallner
  • Wojciech Hanke
  • Manolis Kogevinas
  • Inger Kull
  • Pernille Stemann Larsen
  • Vasiliki Melaki
  • Christine Monfort
  • Karl-Christian Nordby
  • Evridiki Patelarou
  • Kinga Polanska
  • Lorenzo Richiardi
  • Loreto Santa Marina
  • Claudia Snijder
  • Adonina Tardón
  • Manon van Eijsden
  • Tanja G M Vrijkotte
  • Daniela Zugna
  • Mark Nieuwenhuijsen
  • Martine Vrijheid

OBJECTIVES: We assessed whether maternal employment during pregnancy - overall and in selected occupational sectors - is associated with birth weight, small for gestational age (SGA), term low birth weight (LBW), length of gestation, and preterm delivery in a population-based birth cohort design.

METHODS: We used data from >200 000 mother-child pairs enrolled in 13 European birth cohorts and compared employed versus non-employed women. Among employees, we defined groups of occupations representing the main sectors of employment for women where potential reproductive hazards are considered to be present. The comparison group comprised all other employed women not included in the occupational sector being assessed. We performed meta-analyses of cohort-specific estimates and explored heterogeneity.

RESULTS: Employees had a lower risk of preterm delivery than non-employees [adjusted odds ratio (ORadj) 0.86, 95% confidence interval (95% CI) 0.81-0.91]. Working in most of the occupational sectors studied was not associated with adverse birth outcomes. Being employed as a nurse was associated with lower risk SGA infants (ORadj 0.91, 95% CI 0.84-0.99) whereas food industry workers had an increased risk of preterm delivery (ORadj 1.50, 95% CI 1.12-2.02). There was little evidence for heterogeneity between cohorts.

CONCLUSIONS: This study suggests that, overall, employment during pregnancy is associated with a reduction in the risk of preterm birth and that work in certain occupations may affect pregnancy outcomes. This exploratory study provides an important platform on which to base further prospective studies focused on the potential consequences of maternal occupational exposures during pregnancy on child development.

Original languageEnglish
JournalScandinavian Journal of Work, Environment & Health
Issue number4
Pages (from-to)384-396
Number of pages13
Publication statusPublished - Jul 2015

    Research areas

  • Birth Weight, Cohort Studies, Employment, Europe, Female, Gestational Age, Health Behavior, Humans, Infant, Low Birth Weight, Infant, Newborn, Infant, Small for Gestational Age, Maternal Exposure, Meta-Analysis as Topic, Occupations, Pregnancy, Pregnancy Outcome, Premature Birth, Regression Analysis, Risk Factors, Surveys and Questionnaires

ID: 160098822