The effect of carbohydrate intolerance on neonatal birth weight in pregnant women without gestational diabetes mellitus

BACKGROUND: There is still no consensus on screening, threshold levels and treatment of gestational diabetes mellitus. Furthermore, the importance of a positive 50-g glucose screening test in patients who had a negative 100-g oral glucose tolerance test remains controversial. We investigated the impact of the 50-g glucose screening test results on neonatal outcome in pregnant women with uncomplicated pregnancies, who had no risk factors according to ACOG criteria. PATIENTS AND METHODS: Three hundred eighty-six pregnant women with singleton pregnancies were prospectively screened with 50-g glucose challenge test between 24 and 28 weeks. If the test result was >140 mg/dl, a 100-g 3-hour oral glucose tolerance test was performed. Patients with a positive screening test, but not diagnosed as gestational diabetes mellitus constituted the study group, and patients with a negative screening test constituted the control group. Cesarean rates, neonatal birth weights and complications were compared between these groups. RESULTS: The cesarean delivery rates were not statistically different between the study and control groups (8.3% vs. 6.4%, P>0.05). The rates of macrosomic births were 10.0% in the study group, and 6.4% in the control group (P>0.05), but the mean birth weight (3451.67 ± 355.70 g) in the study group was significantly higher than the mean birth weight (3296.29 ± 365.14 g) in the control group (P=0.003). Neonatal hypoglycemia and hyperbilirubinemia was also encountered more often in babies of pregnant women with a positive 50-g glucose challenge test but negative 100-g glucose tolerance test. CONCLUSION: Because of similarities with gestational diabetes mellitus on the basis of perinatal outcomes, the non-diabetic pregnant women with 50-g glucose screen test result over 140 mg/dl but a negative 100-g OGTT should be followed closely.