Psychosocial working conditions during pregnancy and adverse pregnancy outcomes: a Danish nationwide register-based cohort study.

Objectives: Evidence regarding the effect of psychosocial working conditions on adverse pregnancy outcomes remains inconclusive. We investigated whether four aspects of psychosocial working conditions were associated with adverse pregnancy outcomes.

Methods: In the Danish National Occupational Cohort with eXposure (DOC*X)-Generation cohort of employed pregnant women, 1977-2018, occupational quantitative demands, influence, emotional demands and physical violence, divided into tertiles, were assessed by job exposure matrices and linked with occupation during pregnancy from the Danish version of the International Standard Classification of Occupations 88. The Danish National Patient Register provided data on miscarriages and the Danish Medical Birth Register data on gestational age and birth weight to estimate preterm birth (PTB) and small for gestational age (SGA) in singleton pregnancies.

Results: The pregnancies in one million women resulted in 13% (~1 921 890 million) miscarriages, 13% (~1 604 96 million) SGA children and 5% (~1 482 493 million) PTB. The risk of miscarriage was higher among women in occupations with high emotional demands (adjusted odds ratio (adjOR)=1.20, 95% CI 1.18 to 1.21) and high physical violence (adjOR=1.24, 95% CI 1.23 to 1.26) compared with those in occupations with low exposure. The combined effect of quantitative demands and influence showed no association or ORs<1 for miscarriage compared with combined low quantitative demands/high influence. The findings on SGA and PTB were inconsistent (adjORs 0.91-1.06).

Conclusions: Our findings suggest that emotional demands and physical violence at work are associated with higher odds of miscarriage, whereas associations between the different exposures and SGA and PTB were inconsistent. Further studies applying individual level measurements of psychosocial working conditions are warranted.