TUESDAY, March 26, 2019 (HealthDay News) -- Night work during pregnancy seems to confer an increased risk for miscarriage, with the risk increased for two or more night shifts the previous week, according to a study published online March 25 in Occupational & Environmental Medicine.
Luise Moelenberg Begtrup, from Frederiksberg Hospital in Copenhagen, Denmark, and colleagues identified a cohort of 22,744 pregnant women by linking data from the Danish Working Hour Database with Danish national registers on births and admissions to hospitals (miscarriage). The risk for miscarriage during pregnancy weeks 4 to 22 was analyzed according to measures of night work. Overall, 377,896 pregnancy weeks were available for follow-up.
The researchers found that compared with women who did not work night shifts, the risk for miscarriage after pregnancy week 8 was increased for women who had two or more night shifts the previous week (hazard ratio, 1.32). The risk for miscarriage was increased in a dose-dependent pattern for the cumulative number of night shifts during pregnancy weeks 3 to 21.
"The new knowledge has relevance for working pregnant women as well as their employers, physicians, and midwifes," the authors write. "Moreover, the results could have implications for national occupational health regulations."