Gestational weight gain greater or less than the Institute of Medicine (IOM) recommended levels was associated with higher risk of adverse maternal and infant outcomes when compared to gestational weight gain within recommended IOM levels, according to a recent systematic review and meta-analysis that included observational studies stratified by prepregnancy body mass index (BMI) category and total gestational weight gain between January 1, 1999, and February 7, 2017. Primary outcomes were small for gestational age (SGA), preterm birth, and large for gestational age (LGA). Secondary outcomes were macrosomia, cesarean delivery, and gestational diabetes mellitus. Researchers found:

• Of 5,354 identified studies, 23 (n=1,309,136 women) met inclusion criteria.
• 47% had gestational weight gain greater than IOM recommendations and 23% had gestational weight gain less than IOM recommendations.
• Gestational weight gain below the recommendations was associated with higher risk of SGA and preterm birth and lower risk of LGA and macrosomia; cesarean delivery showed no significant difference.
• Gestational weight gain above the recommendations was associated with lower risk of SGA and preterm birth and higher risk of LGA, macrosomia, and cesarean delivery.