A multiethnic study of the predictors of macrosomia

This study examined predictors of macrosomia in a multiethnic sample of 213 low-income women diagnosed with gestational diabetes mellitus (GDM) after week 24 of their pregnancy.

Medical records were reviewed retrospectively. Variables examined were mother's height, weight history, educational level, age at diagnosis, weeks at diagnosis and delivery, type of diabetes, mean fasting blood glucose (FBG), and infant's weight, sex, and Apgar scores.

Fifty-one percent of babies were macrosomic. Weight gain, nonpregnant weight, weight at delivery, FBG, and Apgar scores at 1 minute were associated with macrosomia, especially in Hispanic women. Logistic regression revealed that nonpregnant weight was the strongest predictor of macrosomia.

Nonobese GDM mothers with optimal weight gain but with high FBG levels > 90 mg/dL may be at risk for macrosomia. The major concerns with obese GDM mothers are nonpregnant weight and high blood glucose levels, in this order. Education for women with GDM should target these risk factors to decrease macrosomia.