THRESHOLD VALUE OF GLUCOSE SCREENING-TESTS IN PREGNANCY - COULD IT BESTANDARDIZED FOR EVERY POPULATION

We aimed to determine a threshold value that perfectly demarcates wome n at high risk for gestational diabetes mellitus (GDM) in the Turkish population. One thousand gravid women of 24 to 32 weeks of gestation w ere given 50 g, 1-hour glucose screening tests. A 100 g, 3-hour glucos e tolerance test (GTT) was performed on all patients whose screening t est plasma glucose value was 130 mg/dL or greater. The sensitivity and specificity of each screening test value was found, and the GDM rate of each value was calculated. Three-hundred-and-five patients were ide ntified for GTT and 66 were shown to have GDM with two or more abnorma l values in GTT. The incidence of GDM was found to be 6.6%. The maximu m specificity and sensitivity were met at 140 mg/dL. However, this val ue underestimated 12% of patients with GDM, and the lowest value for a positive GTT appeared to be 134 mg/dL. We recommend a 135 mg/dL thres hold for GTT since this threshold accurately diagnoses almost all wome n with GDM while eliminating unnecessary GTT.