Delayed Sleep Midpoint Across Pregnancy Is Associated with Excessive Gestational Weight Gain.

Background: Changes in sleep patterns and body weight occur during pregnancy, yet it is unclear whether sleep patterns are related to gestational weight gain (GWG). This study examined the relationship between maternal sleep across pregnancy and excessive GWG. Methods: Participants from the Michigan Archive for Research on Child Health (MARCH) cohort study, who had singleton births and provided information on fall-asleep and wake-up times during early (first or second) and the third trimesters, were included ( n  = 372). Changes in sleep duration and sleep midpoints throughout pregnancy were calculated. Prepregnancy weight and the last maternal weight before delivery were used to calculate GWG, which was categorized into groups (inadequate, adequate, and excessive). Poisson regression models were used to examine associations between sleep changes and excessive GWG, adjusted for age, race, gestational age, prepregnancy body mass index, income, fetus gender, physical activity, added sugar, and fruit and vegetable intake. Results: Excessive GWG was observed in 46.5% of women, and was more common among those with prepregnancy obesity ( p  < 0.001). Women who delayed sleep midpoint by 1 hour (or more) from the early trimester assessment to the third trimester experienced higher risk of excessive GWG (Risk ratio: 1.3; 95% confidence interval: 1.1-1.7). Single time points of sleep duration and sleep midpoint or changes in sleep duration were not related to GWG. Conclusions: Delay in sleep midpoint from early-mid pregnancy to the third trimester was associated with excessive GWG. Health professionals should consider changes in sleep patterns during pregnancy to identify those prone to excessive GWG.