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First-trimester working conditions and birthweight: a prospective cohort study
Tanja G M Vrijkotte1, Marcel F van der Wal, Manon van Eijsden
1Department of Social Medicine, Academic Medical Centre Amsterdam, 1100 DD Amsterdam, Netherlands. t.vrijkotte@amc.uva.nl
American Journal of Public Health
|June 23, 2009
Summary
High job strain and long work hours in early pregnancy are linked to lower infant birthweight. This combination also increases the risk of delivering a small-for-gestational-age (SGA) infant.
Area of Science:
- Occupational Health
- Maternal and Child Health
- Perinatal Epidemiology
Background:
- Maternal working conditions during pregnancy may impact fetal development.
- Understanding the effects of job strain and work hours on birth outcomes is crucial for public health.
Purpose of the Study:
- To investigate the association between first-trimester working conditions and infant birthweight.
- To determine the impact of job strain and work hours on the risk of delivering a small-for-gestational-age (SGA) infant.
Main Methods:
- A cohort of 7135 pregnant women from the Amsterdam Born Children and Their Development study was analyzed.
- Data on employment and working conditions were collected via questionnaire.
- Infant birthweight and SGA status were the primary outcome measures.
Main Results:
- Working 32+ hours/week was associated with a 43g decrease in mean birthweight.
- High job strain was linked to a 72g decrease in mean birthweight and a 1.5-fold increased risk of SGA.
- The combination of high job strain and long work hours resulted in a 150g birthweight reduction and a 2.0-fold increased risk of SGA.
Conclusions:
- High job strain in early pregnancy is associated with reduced birthweight.
- Maternal job strain and long work hours (≥32 hours/week) increase the risk of delivering an SGA infant.
- Combined high job strain and long work hours pose the greatest risk to infant birthweight and SGA status.
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