Selective Screening for Gestational Diabetes Mellitus

Background The usual approach to detecting gestational diabetes mellitus is to screen all pregnant women by measuring their plasma glucose after a 50-g oral glucose load at 24 to 28 weeks' gestation. Women are referred for an oral glucose-tolerance test if the plasma glucose concentration one hour later is >140 mg per deciliter (7.8 mmol per liter). We hypothesized that the efficiency of screening could be enhanced by considering women's risks of gestational diabetes on the basis of their clinical characteristics. Methods We studied 3131 pregnant women who underwent both the screening and the diagnostic tests. We randomly selected data on half the women and used them to derive new screening strategies. We categorized each woman's risk of gestational diabetes mellitus on the basis of her age, body-mass index before pregnancy, and race. We developed strategies that entailed no screening for low-risk women, usual care for intermediate-risk women, and universal screening with lower thresholds — plasma glucose...