TUESDAY, Nov. 3, 2026 (HealthDay News) -- Gestational weight gain (GWG) outside of recommended ranges is associated with increased severe maternal morbidity (SMM) risk, according to a study published online Oct. 22 in JAMA Network Open.
Sahar Khademioore, from McMaster University Medical Center in Hamilton, Ontario, Canada, and colleagues examined the association between GWG and SMM across prepregnancy body mass index (BMI) categories. The analysis included nearly 1.04 million singleton pregnancies (April 1, 2012, to March 31, 2022).
The researchers found that 52.8 percent of pregnancies had excessive GWG and 15,119 experienced SMM (14.59 per 1,000 births). Excessive GWG was associated with increased SMM across all BMI categories, including underweight (adjusted rate ratio [ARR], 1.33), normal weight (ARR, 1.24), overweight (ARR, 1.16), obesity class I (ARR, 1.21), obesity class II (ARR, 1.28), and obesity class III (ARR, 1.24), compared with adequate GWG. There was an association between inadequate GWG and increased SMM, predominantly among individuals with normal weight (ARR, 1.13) and overweight (ARR, 1.19). There were nonlinear associations between GWG and SMM across all BMI categories, with risk elevated at both low and high GWG in individuals with underweight, normal weight, and overweight. In those with obesity (classes I to III), risk was concentrated at high GWG values.
"Because weight gain is something that can potentially be addressed, understanding how it relates to severe complications gives us an opportunity to better support maternal health," Khademioore said in a statement.
One author disclosed ties to the pharmaceutical industry.
