The Effectiveness of 50 Gram Oral Glucose Challenge Test in Gestational Diabetes Screening

Abstract

Objective: Our objective is to investigate whether 50 gr GCT is enough and effective when performed for pregnant women only carrying the risk factors for GDM. Material and methods: A total of 426 pregnant women having 24-28 weeks of pregnancy were enrolled to this prospective study between November 2005 and November 2006 in Gynecology and Obstetrics Departments of Ondokuz Mayis University. Pregnant women were divided into two groups according to the presence of risk factors for GDM. 50 gr GCT was applied to both groups. 100 gr oral glucose tolerance test (OGTT) was applied to the cases with positive 50 gr GCT. Positive predictive value (PPV) of 50 gr GCT was calculated for both groups. Results: Of 426 evaluated pregnant women, 222 pregnant women had no risk factor for GDM and the rest 204 pregnant women had at least one risk factor. 4 out of 18 pregnant women who do not carry risk factors, and who had 100 gr OGTT had the diagnosis of GDM, in prevalance of 1,8%. 18 out of 44 pregnant women who carry risk factors, and who had 100 gr OGTT had the diagnosis of GDM, in prevalance of 8,8%. Of 426 pregnant women, 22 had diagnosis of GDM and prevalance of GDM was found to be as 5,2%. While PPV of 50 gr GCT is 40,9% in the pregnant women who carry risk factors, it is 22,2% in the pregnant women only carrying the risk factors. There is a statistically significant difference between the two groups (P<0.05). Conclusion: This study suggested that in screening of the GDM, it is more suitable to apply 50 gr GCT to the pregnant women only carrying risk factors.