In a clinical trial, investigators aimed to determine the optimal gestational weight gain for women with obesity to minimize the risk for neonatal and maternal adverse events. The study included women with obesity who delivered a full-term singleton in a head-down position. The primary outcome was a composite risk of significant neonatal morbidity, while secondary outcomes included combined risks of substantial maternal morbidity, minor neonatal and maternal morbidity, and cesarean delivery.
The study's results indicated that among the 16,808 eligible women with obesity, the optimal gestational weight change for all women was -1 to +4 kg. This weight change was associated with a reduced risk of significant neonatal morbidity compared to the current recommendations.
Researchers also analyzed the data based on the class of obesity. Individuals with a body mass index (BMI) between 30 and 35 are classified as class 1 obesity, while those with a BMI between 35 and 40 are classified as class 2 obesity. Class 3 obesity, on the other hand, includes individuals with a BMI of 40 or higher and is sometimes referred to as "severe" obesity. A weight change of -1 to +4 kg for class I, -2 to +2 for class II, and -2 to +3 kg for class III was associated with a reduced risk of significant neonatal morbidity.