Abstract
BACKGROUND: Maternal obesity (defined as prepregnancy body mass index [BMI] ≥30 kg/m) is associated with increased risk of neonatal death. Its association with infant death, postneonatal death, and cause-specific infant death is less well-characterized. METHODS: We studied the association between maternal obesity and the risk of infant death by using 1988 US National Maternal and Infant Health Survey data. A case-control analysis of 4265 infant deaths and 7293 controls was conducted using SUDAAN software. Self-reported prepregnancy BMI and weight gain were used in the primary analysis, whereas weight variables in medical records were used in a subset of 4308 women. RESULTS: Compared with normal weight women (prepregnancy BMI = 18.5-24.9 kg/m) who gained 0.30 to 0.44 kg/wk during pregnancy, obese women had increased risk of neonatal death and overall infant death. For obese women who had weight gain during pregnancy of