Authors
Sreekala S1, Lalitha K2, Poulose K P3. 1Consultant in Obstetrics and Gynecology, SUT Hospital, Pattom, Trivandrum, Kerala, India. 2Principal Consultant in Obstetrics & Gynecology, S.U.T Hospital, Pattom, Thiruvananthapuram, Kerala, India, Trivandrum. 3Chief Physician and HOD, Department of Medicine, SUT Hospital Pattom, Emeritus Professor of Medicine, SUT Medical College Trivandrum
Abstract
Objectives: To determine whether:1) repeated screening of pregnant women for gestational diabetes improves detection. 2) lowering the GCT cut off value from 140 mg% to 130mg% increases diagnostic yield. 3) a 2 hr PPBS after 100 gm glucose load yields comparable diagnostic yield to a formal 100 gm 3 hour GTT.
Materials and methods: Pregnant women presenting at the antenatal clinic of SUT hospital were studied. Known pregestational diabetes cases were excluded from the study. Antenatal women underwent a two step diagnostic procedure in each of the three trimesters – initial 50 gm Glucose Challenge screening test (GCT) followed by a 3 hour 100gm oral Glucose tolerance test (GTT) as a diagnostic test in the GCT positive cases. All patients were followed up till delivery and maternal and perinatal outcomes were analysed.
Results: 376 women were screened in the first trimester, 786 in the second trimester and 676 in the third trimester and GDM was detected in 6 (12.76%), 21(44.7%) and 20 (42.55%) respectively. Lowering the cut off value of GCT from 140 mg/dl to 130 mg/ dl was found to increase diagnostic yield by 25.1%. Using a single 2 hour cut off value of 140mg/dl after a 100 gm glucose load was found to improve the diagnosis by 31.9% as compared to the 3 hour GTT.
Conclusion: Repeated screening for GDM during the three trimesters helps in identifying more women with GDM . While a lower cut off for the screening test may be advantageous, a single step diagnostic procedure consisting of a 2 hour PPBS of 140mg/dl after a glucose load is more convenient, cost effective and improved the diagnostic yield.
Keywords: Gestational diabetes, Screening, GDM