Excessive maternal weight gain key to LGA infants

Expectant mothers with excessive gestational weight gain have a higher risk of delivering a large-for-gestational age (LGA) infant than those whose weight gain falls within standard guidelines, according to a recent study in Obstetrics & Gynecology.

Researchers from the Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention analyzed linked birth certificates and maternal hospital discharge data on live, singleton deliveries in Florida from 2004 to 2008. Multivariable logistic regression was used to assess the independent contributions of the mother’s prepregnancy body mass index (BMI), gestational weight gain, and gestational diabetes mellitus (GDM) status on the risk of a LGA infant by race and ethnicity, while controlling for maternal age, nativity, and parity.

Prevalence of LGA infants was 5.7% in normal-weight women with adequate gestational weight gain and no GDM. Prevalence among women with BMI ≥25 was 12.6% and 13.5% among women who had excess gestational weight gain. Among women with GDM, the prevalence of LGA infants was 17.3%. Across all race or ethnic groups, GDM contributed the least to LGA (2.0% to 8.0%) whereas excessive weight gain contributed the most (33.3% to 37.7%). The authors estimated that Asian and Pacific Islanders and non-Hispanic black women might have 46.8% and 61.0% fewer LGA births, respectively, if they had none of the three exposures.

Concluding that excessive maternal weight gain is the greatest risk factor for LGA infants, the investigators urged ob/gyns to provide pregnant patients with guidelines for gestational weight gain and counsel those whose weight  during pregnancy is too high.

To get weekly advice for today's Ob/Gyn, subscribe to the Contemporary Ob/Gyn Special Delivery.