A comparison of fasting plasma glucose and glucose challenge test for screening of gestational diabetes mellitus

Glucose challenge test (GCT) has been used as an effective screening test for gestational diabetes mellitus (GDM), though it has its own limitations. Hence, we assessed the effectiveness of fasting plasma glucose (FPG) as a simpler alternative procedure. A prospective study was done in 500 pregnant women with gestational age between 22 and 37 weeks. FPG, GCT and GTT were performed in all patients using the glucose oxidase/peroxidase method. The overall sensitivity and specificity of GCT were 75.0% and 92.0%, respectively and the corresponding values for FPG were 88.8% and 95.2%. The positive predictive value and negative predictive value were 42.2% and 97.9% for GCT and 59.2% and 99.1% for FPG, respectively. We conclude that FPG can be used as an effective screening tool for gestational diabetes mellitus.