TIME-DEPENDENT GESTATIONAL DIABETES SCREENING VALUES

Objective: This study was undertaken to determine use of different cut -off values with regard to the time of the patient's last meal in scre ening for gestational diabetes mellitus which could result in better r esults and change patient management. Methods:: Two hundred and sevent y-four non-diabetic women undergoing routine screening for glucose int olerance between 26 to 28 weeks' gestation were classified with regard to the time of previous meal. A glucose challenge test and an oral gl ucose challenge test were conducted for each patient in the study. Res ults were evaluated with both a standard cut-off value of 140 mg/dl wi thout regard to the time of the last meal and suggested cut-off values of 148 mg/dl, 142 mg/dl, and 150 mg/dl if the patient ate < 2 h, 2-3 h, and > 3 h before the screening test, respectively. Results: Two hun dred and seventy-four women completed the study. With these suggested cut-off values, the number of patients with a positive glucose challen ge test dropped from 15.7% to 11.3%. With these cut-off values, positi ve predictive value increased from 27.3% to 32.3%. Conclusions: The ti me since previous meal affects 50 g glucose challenge test results. Th ese new cut-off values would lead to improved efficiency of the screen ing test and decreased frequency with which patients require the 3-h o ral glucose tolerance test. (C) 1997 International Federation of Gynec ology and Obstetrics.