Accuracy of Fasting Blood Sugar Versus Glucose Challenge Test as Screening Test for Gestational Diabetic Mellitus

Objective: To determine the accuracy of fasting blood sugar (FBS) and glucose challenge test (GCT), for the diagnosis of gestational diabetes mellitus in pregnant women presenting at tertiary care hospital. Setting: Department of Gynaecology and Obstetrics at Isra university hospital Hyderabad. Duration: Six month from February 2017 to July 2017 Design: cross sectional study. Subject and Methods: A total of 158 pregnant women with suspected gestational diabetes, aged between 18 to 45 years, gestational age of 24-28 weeks as per ultrasound and of either parity were included in this study. After taking history and examination all pregnant women with suspected GDM underwent both tests the blood sugar (FBS) and the glucose challenge test (GCT). FBS was performed after 1 hour of 50 mg glucose load in same woman. All information was recorded in predesign proforma. Results: Overall 158 pregnant females with suspected gestational diabetes were studied their mean age was 34.98 +/- 6.64 years, mean FBS was 92.91+10.23 mg/dl and mean GCT was 126.63+18.17 mg/dl. Family history of diabetic mellitus was observed in 56.96%. Gestational diabetes mellitus in 29.11% was detected by FSB >92 mg/dl while 21.52% were detected by GCT >130 mg/dl. Kappa (k=0.734 p=0.0005) statistics showed that there were strong association between FBS and GCT in detection of GDM. Conclusion: In our study, accuracy of fasting blood sugar (FBS) and glucose challenge test (GCT), for the diagnosis of gestational diabetes mellitus in pregnant women was high. However FBS and GCT measurement are adequate methods to screen for GDM.