Screening for gestational diabetes with the one-hour 50-g glucose test

A one-year experience of screening for gestational diabetes is reported. Patients with any of seven risk factors were screened at the time of prenatal registration. Those without risk factors, and those not found to be diabetic by 24 weeks' gestation, were tested later in pregnancy. Of 4116 patients, 77% had at least one risk factor. The prevalence of diabetes in patients with risk factors was significantly greater than among those with no risk factors (P less than .001). Of 936 patients who had no risk factors, four were found to have diabetes. Multiple logistic regression analysis suggested that family history, obesity, and age over 25 years contributed significantly to the prediction of gestational diabetes. More than 10% of gestational diabetics had screening values between 135-139 mg/dL. Among patients whose early screening values were elevated and whose initial glucose tolerance tests were normal, the odds of being classified ultimately as a gestational diabetic were 7.3 times that of patients whose initial screening tests were normal. Selective screening based on risk factors including maternal age may enhance detection of diabetes early in gestation.