Prepregnancy BMI, Pregnancy Weight Gain, and Risk for Large Infants

Excess weight gain during pregnancy increases the risk for excess fetal weight gain, which increases the risk for macrosomic and large for gestational age (LGA) infants. Investigators examined whether maternal prepregnancy body-mass index (BMI) altered the relation between pregnancy weight gain and LGA or macrosomia (birth weight, ≥4.5 kg) using data for 104,980 singleton term births without congenital anomalies from the 2000–2005 Pregnancy Risk Assessment Monitoring System.

Women were classified by prepregnancy BMI as lean (<19.8 kg/m²), normal (19.8–26.0), overweight (26.1–29.0), and obese (>29.0). Weight gain in pounds during pregnancy was divided into five categories (≤14, 15–25, 26–35, 36–45, and ≥46), and the researchers determined whe…