Poor Sleep in Pregnancy Linked to Childhood Obesity Risk

By the Editorial Team · Tuesday, September 22, 2026

A study by researchers at the University of Southern California found that poor sleep quality in the third trimester of pregnancy is linked to higher weight gain and increased obesity risk in children by age two. This connection highlights the importance of maternal sleep health as a potential factor in managing early childhood obesity, warranting further investigation into underlying biological mechanisms.

A recent study has found that poor sleep quality during pregnancy, particularly in the third trimester, may be associated with an increased risk of obesity in early childhood. Researchers from the University of Southern California examined 645 mother-child pairs to explore how maternal sleep patterns affect birth weight and subsequent growth.

The study revealed that approximately 25% of pregnant women experienced clinically poor sleep quality during late pregnancy. Babies born to these mothers tended to have lower birth weights initially but showed higher weight gain in the first two years of life. By the age of one, children of mothers with poor sleep weighed on average 347 grams more than those whose mothers slept well. The weight difference peaked at 17 months, when these children were 752 grams heavier.

Dr. Xiaoran Yang, the lead author, highlighted the prevalence and often overlooked nature of poor sleep during pregnancy. She emphasized the importance of monitoring maternal sleep as a potential measure to promote healthier growth outcomes for children.

The underlying mechanisms remain unclear, but Dr. Carrie Breton, a co-author, suggested that inadequate sleep might influence metabolic processes in mothers, children, or both. These metabolic changes could impact how neonatal fat is distributed, contributing to variations in early weight gain.

Childhood obesity rates have risen significantly in recent years. In the United Kingdom, about one in ten children are classified as obese when entering primary school, increasing to one in five by the end of year six. Medical professionals warn that obesity in childhood often persists into adulthood, increasing the risk of chronic health issues.

The study’s findings underscore the potential role of maternal sleep health in early childhood weight trajectories and suggest that improving sleep quality during pregnancy could be a step toward addressing the growing problem of childhood obesity. Further research is needed to clarify the biological pathways involved and to determine effective interventions.

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