Excessive gestational weight gain most dangerous for underweight women, research suggests
For women underweight at baseline, excessive weight gain was associated with a 33% higher risk of severe maternal morbidity.
Both inadequate and excessive gestational weight gain are associated with maternal morbidity, but underweight women who gain excessive weight are at the highest risk, research suggests.
The retrospective cohort data presented at the 2026 International Congress on Obesity last month involved more than a million singleton Canadian pregnancies from 2012 to 2022, including about 1.5% with a severe maternal outcome.
It found that 53% involved excessive weight gain and 19% involved inadequate weight gain, based on US Institute of Medicine recommendations.
The recommendations suggest appropriate gestational weight gain is 12.5-18kg for underweight women, 11.5-16kg for normal-weight women, 7-11.5kg for overweight women and 5-9kg for obese women.
