Physical exertion at work during pregnancy did not increase risk of preterm delivery or fetal growth restriction
Q In pregnant working women, does physical exertion at work (standing, lifting, night work, and long hours) increase the risk of preterm delivery or fetal growth restriction?
prospective cohort study.
prenatal clinics at 3 hospitals in North Carolina, USA.
1908 English speaking women ⩾16 years of age who were 24–29 weeks pregnant with a singleton gestation and had worked ⩾28 days in the first 2 trimesters of pregnancy.
physical exertion at work during the first or second trimester, including standing, heavy lifting (>11 kg), regular night work (10 pm to 7 am), and long hours (exposure determined by telephone interview at 24–31 wks gestation).
preterm delivery (<37 wks gestation) and small for gestational age (SGA) infant (birth weight <10th percentile).
In the first trimester, 25% of women stood ⩾30 hours/week, 10% lifted heavy objects ⩾13 times/week, 9% worked nights regularly, and 16% worked ⩾46 hours/week; proportions …