Objectives. We examined the association of prepregnancy body mass index
(BMI) and gestational weight gain (GWG) with risk of death during infancy using
the Institute of Medicine’s (IOM’s) Pregnancy Weight Gain Guidelines.
Methods. We obtained maternal and infant data for 2004–2008 from 159 244
women with a singleton, full-term, live birth in the 41 states that participated in
phase 5 of the Pregnancy Risk Assessment Monitoring System. We fit logistic
regression models to estimate the association between prepregnancy BMI,
GWG, and risk of death during infancy, controlling for confounders.
Results. Only 34% of women gained the IOM-recommended amount of weight
during pregnancy. Infants born to underweight, normal-weight, and overweight
women with inadequate GWG had odds of mortality during infancy that were
6.18, 1.47, and 2.11 times higher, respectively, than those of infants born to
women with adequate GWG. Infants born to obese women with excessive
weight gain had a 49% decreased likelihood of mortality.
Conclusions. A significant association exists between inadequate GWG and
infant death that weakens with increasing prepregnancy BMI; weight gain
beyond the recommended amount appears to be protective against infant
mortality.