Metabolic health before and during pregnancy may play a more critical role in maternal and infant outcomes than weight gain alone, new research suggests.
A study from Pennington Biomedical Research Center found that pregnant women with metabolically unhealthy obesity were significantly more likely to develop gestational diabetes, regardless of how much weight they gained.
Published in the Journal of the American Medical Association, the study, “Metabolic Health and Heterogenous Outcomes of Prenatal Interventions: A Secondary Analysis of a Randomized Clinical Trial,” analyzed data from the “Lifestyle Interventions for Expectant Moms” trial.
Researchers compared outcomes among women with metabolically healthy obesity—obesity without major metabolic risk factors—and those with metabolically unhealthy obesity, defined as obesity with at least two risk factors such as high blood sugar, high blood pressure, or elevated cholesterol.
The findings revealed that women with metabolically unhealthy obesity gained nearly 37% less weight during pregnancy than those with metabolically healthy obesity. Despite lower weight gain, they were twice as likely to develop gestational diabetes.
Among 400 women with obesity, 24% of metabolically unhealthy participants developed gestational diabetes, compared to 10% of metabolically healthy participants. Infants born to metabolically unhealthy mothers also had higher body fat.
“The research demonstrates exciting opportunities to improve metabolic health for expectant mothers both before conception and throughout pregnancy,” said Dr. John Kirwan, Executive Director of Pennington Biomedical. He praised the work of Drs. Emily Flanagan, Leanne Redman, and Kimberly Drews for highlighting the importance of metabolic wellness in maternal health.
The study also assessed prenatal lifestyle interventions introduced near the end of the first trimester. Both groups responded similarly to the interventions, suggesting that earlier, targeted strategies aimed specifically at improving metabolic health—rather than solely controlling weight gain—could better reduce prolonged fetal exposure to high glucose and lipid levels, particularly in women with elevated metabolic markers at the start of pregnancy.
