Effect of number of abnormal oral glucose tolerance test (OGTT) values on birthweight in women with gestational diabetes

BACKGROUND & OBJECTIVES To examine the effect of abnormal oral glucose loading (OGL) and number of abnormal oral glucose tolerance test (OGTT) values on foetal weight in Turkish pregnant women. METHODS This retrospective study included 810 pregnant women between 24 and 28 wk of gestation who were screened for gestational diabetes mellitus (GDM). Women were grouped according to degree of glucose intolerance and compared for clinical, biochemical parameters. Women who delivered macrosomic infants were compared with those who delivered normal infants. RESULTS GDM was detected in 70 (8.6%) women. Median age and infant birthweight of GDM cases were higher than the other groups. Infants of women with GDM weighted 200 g more than infants of non-GDM cases. No difference was found in terms of birthweight between diabetes cases with 2, 3 or 4 OGTT values abnormality. INTERPRETATION & CONCLUSIONS The number of abnormal OGTT values in GDM cases had no effect on foetal weight. Macrosomia was observed more in GDM cases than in non-GDM cases. Birthweight was significantly higher in women with GDM despite the therapy used for regulation of blood glucose. This may be related to ethnical, dietary, nutritional differences, and treatment compliance in our study population.