Studies on diagnostic criteria for gestational diabetes mellitus by 75 g glucose tolerance test.

The glucose tolerance test (GTT) was performed on 722 pregnant women to evaluate the diagnostic criteria for gestational diabetes mellitus (GDM) by the 75 g GTT. The upper limits of the normal levels of plasma glucose were defined as 100 mg/dl, 180 mg/dl and 150 mg/dl at fasting and 1 and 2 hours after glucose loads, respectively. The individuals were termed GDM if 2 or more values were greater than the upper limit at each time point. The incidence of GDM based on our criteria was 3.3% of all subjects. The insulinogenic indices were low and hemoglobin Ale levels were high in the women with GDM. The incidence of fetal and neonatal complications born to mothers with GDM was high. The patients diagnosed as GDM in the present study appeared to show certain differences in clinical features compared to pregnant women with normal glucose tolerance.