1062 Sleep period onset variability and risk of preterm birth

Abstract

Although the beneficial role of healthy sleep in pregnancy is well established, this literature has focused on sleep duration or quality with little attention to other indicators of sleep health. Intraindividual variability in sleep period onset or the extent to bedtime varies from night-to-night, is linked to adverse outcomes outside of pregnancy. We examined the association between sleep period onset variability (SPOV) and the risk of preterm delivery (PTD) in a racially and socioeconomically diverse cohort of pregnant women. This was a prospective cohort study of women with singleton pregnancies who delivered at a Midwestern academic tertiary care center. We excluded patients with miscarriages or delivery 10 continuous days of actigraphy data from either the first or second trimester). We extracted the time of sleep period onset and awake time from a wrist actigraphy device during the first and second trimesters. The primary outcome was PTD<37 weeks. The secondary outcome was PTD<34 weeks. We modeled associations between quartiles of SPOV) and risk of PTD using multivariable Poisson regression adjusted for potential confounders. Of the 583 women with complete actigraphy data, 78 (13%) had a PTD < 37 weeks and 27 (4.6%) had a PTD83 mins) experienced a fifty percent increased risk of PTD < 37 weeks (aRR 1.51; 95% CI 1.08, 2.10) and nearly double the risk of PTD<34 weeks (aRR 1.97; 95% CI 1.08, 3.74). When stratified by type of preterm birth (spontaneous or indicated), we observed no association between SPOV and PTD in either group. The positive association with SPOV suggests that irregular sleep period onset may be a modifiable risk factor for preterm birth. Although we had a limited sample size to detect differences in the type of PTD, these data suggest that interventions to promote a consistent daily bedtime may mitigate adverse outcomes.View Large Image Figure ViewerDownload Hi-res image Download (PPT)