An appropriate test for diagnosis of gestational diabetes mellitus.

Early diagnosis of GDM is necessary to reduce maternal and fetal morbidity and mortality. As all approaches to diagnosis of GDM are costly and difficult, we meant to find an appropriate and simple way to perform this test. One-thousand six-hundred and fifty-three pregnant women were screened for GDM at 24-28 weeks of gestation. Initial screening was done by a glucose challenge test with 50 g glucose. If the 1-h blood glucose level exceeded 130 mg/dl, then a 3-h oral glucose tolerance test (OGTT) with 100 g glucose was performed, and diagnosis was established according to ADA criteria. For determining which plasma glucose level is the best test for diagnosis of GDM, we used receiver operative characteristic cures (ROC) by plotting sensitivity versus one minus specificity at different times of plasma glucose levels in OGTT. In 732 pregnant women with a positive GCT, a 2-h plasma glucose level above 150 mg/dl was the most powerful test for detecting GDM, which revealed a sensitivity and specificity of 0.84 (0.81-0.86) and 0.94 (CI: 0.92-0.96), respectively. The results of this study suggest that 2-h 100 g OGTT could be an appropriate approach to diagnose GDM, which is cost-effective and could reduce laboratory workload.