Mothers' poor sleep in late pregnancy linked to higher obesity risk in children

A prospective study of 645 mother-child pairs in a Los Angeles cohort examined whether sleep quality late in pregnancy was associated with children’s growth through age two. Researchers assessed mothers’ sleep using the Jenkins Sleep Scale and measured children’s height and weight during follow-up or from medical records. About 26% of mothers reported poor sleep quality. Their babies weighed less from birth through six months, then became heavier than children of mothers with better sleep. The difference was about 347 grams at age one and peaked at roughly 752 grams at 17 months. The pattern was strongest among boys and children born at term.

The findings suggest that poor sleep in late pregnancy may be associated with altered early growth, a trajectory relevant to later obesity risk. The association was not explained by commonly considered factors such as children’s feeding practices. Researchers propose that sleep-related changes in maternal or fetal metabolic programming, inflammation, or stress pathways could help account for the pattern, but the study did not establish a biological mechanism or prove that poor sleep causes later obesity. Because the research followed a Hispanic population, it also addresses a group underrepresented in earlier studies of pregnancy sleep and childhood weight. The authors argue that routine prenatal care could include sleep-quality screening, potentially identifying families who may benefit from support and helping promote healthy growth.