Study objectives: We evaluated the influence of maternal self-reported habitual sleep duration during early pregnancy on blood pressure (BP) levels and risk of hypertensive disorders of pregnancy.
Design: Prospective cohort study.
Setting: Clinic-based study.
Participants: A cohort of 1,272 healthy, pregnant women.
Measurements and results: We abstracted maternal antenatal BP values from medical records and estimated mean BP differences across hours of sleep categories in regression models, using generalized estimating equations. Odds ratios (OR) and 95% confidence intervals (95% CIs) for pregnancy induced hypertension (PIH) and preeclampsia (PE) in relation to long and short sleep duration were estimated. Mean 1st and 2nd trimester systolic (S) and diastolic (D) BP values were similar among women reporting to be short sleepers (< or = 6 h) vs. women reporting to sleep 9 hours. However, both short and long sleep duration in early pregnancy were associated with increased mean 3rd trimester SBP and DBP. For example, mean 3rd trimester SBP was 3.72, and 2.43 mm Hg higher for women reporting < or = 6 h and 7-8 h sleep, respectively, compared with women reporting 9 h of sleep. Mean 3rd trimester SBP was 4.21 mm Hg higher for women reporting long sleep (> or = 10 h) vs. the reference group. Short and long sleep durations were associated with increased risks of PIH and PE. The ORs for very short (< 5 h) and long (> or = 10 h) sleepers were 9.52 (95% CI 1.83 to 49.40) and 2.45 (95% CI 0.74 to 8.15) for PE.
Conclusions: Our findings are consistent with a larger literature that documents elevated blood pressure and increased risks of hypertension with short and long sleep duration.