Prevalance of impaired glucose tolerance and its association with adverse perinatal outcomes in non-gestational diabetes pregnancies

Objective: Gestational diabetes mellitus (GDM) is characterized by glucose intolerance with onset during pregnancy and is one of the most common metabolic disorders complicating pregnancy. The aim of this study was to evaluate the risk of maternal and neonatal outcomes in non-gestational diabetes pregnancies with abnormal glucose challenge test (GCT) and abnormal glucose tolerance test (GTT) results. Methods: In this retrospective cohort study of 2982 singleton pregnancies, all patients underwent a non-fasting 50 g GCT at 24 to 28 weeks of gestation. A GCT cutoff of ≥ 140 mg/dl was selected. Women with an elevated GCT underwent prompt diagnostic testing with a 3-hour GTT. Subjects were divided into four groups according to GCT and GTT results. Results: There was an impaired glucose tolerance in 19.2 % of patients and 14.7 % of them had mild glucose intolerance and 4.5 % of them had moderate glucose intolerance. As expected, there was statistically significant difference in fetal macrosomia, neonatal hypoglicemia, PE, primary CS, and preterm birth between secreening negative and GDM patients (p < 0.0001). We also observed statistically significant difference in neonatal hypoglicemia (p = 0.0001) and PE (p = 0.0277) between screning negative and mild glucose intolerance group. Moreover, there was a significant difference in fetal macrosomia (p=0.0480) between mild glucose intolerance and moderate glucose intolerance groups. Conclusion: Compared with screening negative group, mild and moderate glucose intolerance are associated with increased adverse maternal and neonatal outcomes even in the absence of GDM.