Cutoff value of Glucose Challenge Test for Screening GDM

This study aimed to investigate the cut-off value of glucose challenge test (GCT) for screening Gestational Diabetes Mellitus (GDM) in a Bangladeshi population. A total of 224 Bangladeshi pregnant women who underwent a GCT were prospectively investigated. GCT was performed between 24 to 28 weeks of gestation. Women demonstrating GCT exceeding 130 mg/dl (>7.2mmol/l) received a 75 g, 2 hr oral glucose tolerance test to determine whether or not they had GDM. Twenty three (10.3%) women were diagnosed to have GDM. The receiver-operator characteristics curve identified a GCT finding above 174 mg/dl as the cut-off value for detecting GDM, which showed sensitivity, specificity, PPV and NPV of 35%, 90%, 80% and 68% respectively. Based on PPV and NPV, our data suggest that 1 hr-50g GCT is a feasible and acceptable screening test and a cut-off value of 174 mg/dl, as the post-challenge serum glucose, may be appropriate for screening GDM in Bangladeshi population by this test.