Association of maternal body mass index, excessive weight gain, and gestational diabetes mellitus with large-for-gestational-age births.

Objective: To estimate the percentage of large-for-gestational age (LGA) neonates associated with maternal overweight and obesity, excessive gestational weight gain, and gestational diabetes mellitus (GDM)-both individually and in combination-by race or ethnicity.

Methods: We analyzed 2004-2008 linked birth certificate and maternal hospital discharge data of live, singleton deliveries in Florida. We used multivariable logistic regression to assess the independent contributions of mother's prepregnancy body mass index (BMI), gestational weight gain, and GDM status on LGA (birth weight-for-gestational age 90 percentile or greater) risk by race and ethnicity while controlling for maternal age, nativity, and parity. We then calculated the adjusted population-attributable fraction of LGA neonates to each of these exposures.

Results: Large-for-gestational age prevalence was 5.7% among normal-weight women with adequate gestational weight gain and no GDM and 12.6%, 13.5% and 17.3% among women with BMIs of 25 or higher, excess gestational weight gain, and GDM, respectively. A reduction ranging between 46.8% in Asian and Pacific Islanders and 61.0% in non-Hispanic black women in LGA prevalence might result if women had none of the three exposures. For all race or ethnic groups, GDM contributed the least (2.0-8.0%), whereas excessive gestational weight gain contributed the most (33.3-37.7%) to LGA.

Conclusion: Overweight and obesity, excessive gestational weight gain, and GDM all are associated with LGA; however, preventing excessive gestational weight gain has the greatest potential to reduce LGA risk.