Association of fewer hours of sleep at 6 months postpartum with substantial weight retention at 1 year postpartum.

Shorter sleep duration is linked to obesity, coronary artery disease, and diabetes. Whether sleep deprivation during the postpartum period affects maternal postpartum weight retention remains unknown. This study examined the association of sleep at 6 months postpartum with substantial postpartum weight retention (SPPWR), defined as 5 kg or more above pregravid weight at 1 year postpartum. The authors selected 940 participants in Project Viva who enrolled during early pregnancy from 1999 to 2002. Logistic regression models estimated odds ratios of SPPWR for sleep categories, controlling for sociodemographic, prenatal, and behavioral attributes. Of the 940 women, 124 (13%) developed SPPWR. Sleep distributions were as follows: 114 (12%) women slept < or =5 hours/day, 280 (30%) slept 6 hours/day, 321 (34%) slept 7 hours/day, and 225 (24%) slept > or =8 hours/day. Adjusted odds ratios of SPPWR were 3.13 (95% confidence interval (CI): 1.42, 6.94) for < or =5 hours/day, 0.99 (95% CI: 0.50, 1.97) for 6 hours/day, and 0.94 (95% CI: 0.50, 1.78) for > or =8 hours/day versus 7 hours/day (p = 0.012). The adjusted odds ratio for SPPWR of 2.05 (95% CI: 1.11, 3.78) was twofold greater (p = 0.02) for a decrease in versus no change in sleep at 1 year postpartum. Sleeping < or =5 hours/day at 6 months postpartum was strongly associated with retaining > or =5 kg at 1 year postpartum. Interventions to prevent postpartum obesity should consider strategies to attain optimal maternal sleep duration.