LAUSR

Key Points Question What is the association of gestational weight gain (GWG) with perinatal outcomes among twin pregnancies across prepregnancy body mass index categories in the US? Findings In this cohort study of 200 810 individuals using data from the National Center for Health Statistics, composite adverse perinatal outcome risks showed a U-shaped association with GWG across prepregnancy body mass index categories. The optimal GWG range for individuals with underweight was similar to that for individuals with normal weight but decreased with increasing severity of obesity. Meaning These findings may inform prenatal counseling regarding optimal GWG for twin pregnancies and suggest the necessity of updating the current US Institute of Medicine guidelines on GWG.