The Association between Body Mass Index and Gestational Diabetes Mellitus Varies by Race/Ethnicity

We examined body mass index (BMI) as a screening tool for gestational diabetes (GDM) and its sensitivity among different racial/ethnic groups. In a retrospective cohort study of 24,324 pregnant women at University of California, San Francisco, BMI was explored as a screening tool for GDM and was stratified by race/ethnicity. Sensitivity and specificity were examined using chi-square test and receiver-operator characteristic curves. BMI of >= 25.0 kg/m(2) as a screening threshold identified GDM in > 76% of African-Americans, 58% of Latinas, and 46% of Caucasians, but only 25% of Asians (p < 0.001). Controlling for confounders and comparing to a BMI of <= 25, African-Americans had the greatest increased risk of GDM (adjusted odds ratio [AOR] 5.1, 95% confidence interval [CI]: 3.0 to 8.5), followed by Caucasians (AOR 3.6, 95% CI: 2.7 to 4.8), Latinas (AOR 2.7, 95% CI: 1.9 to 3.8), and Asians (AOR 2.3, 95% CI: 1.8 to 3.0). BMI's screening characteristics to predict GDM varied by race/ethnicity. BMI can be used to counsel regarding the risk of developing GDM, but alone it is not a good screening tool.