- Night-shift work during pregnancy in a Danish cohort was not associated with an increased risk for preterm birth.
Why this matters
- Research on the effects of night-shift work on pregnancy is mixed.
- It has been suggested that working at night causes changes in the circadian rhythm because of exposure to light.
- It is difficult to counsel women.
- Night-shift work was not associated with increased risk for preterm birth:
- ≥13 shifts of night work in the first trimester: aOR, 0.84 (95% CI, 0.64-1.08);
- ≥11 night shifts in the second trimester: aOR, 1.01 (95% CI, 0.73-1.37).
- Cohort obtained from the Danish Working Hour Database, a national database created from administrative payroll data of women working in administration and public hospitals, between 2007 and 2013.
- Data on exposure to night work were retrieved from the database.
- Pregnant women with at least 1 night shift during the first 22 weeks of gestation (n=10,202) compared with those without night shifts (n=6299).
- Funding: Danish Working Environment Research Fund.
- Danish population; results may not be generalizable.