ABSTRACT
OBJECTIVE: The International Association of Diabetes and Pregnancy Study Group (IADPSG) guidelines for gestational diabetes mellitus (GDM) diagnosis determines that fasting, 1-h and 2-h glucose values may contribute independently to adverse outcomes. However, given the different physiological bases of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), differences in pregnancy outcomes are to be expected. This study aimed to determine whether classification of GDM women according to glucose homoeostasis results in heterogeneity in maternal and/or fetal outcomes. MATERIAL AND METHODS: Of the 75 pregnant women included after a 75-g 2-h OGTT performed between weeks 24-32 of gestation as per WHO criteria, 55 were classified as GDM (16 with IFG and 39 with IGT) according to IADSPG criteria. Their anthropometric and metabolic characteristics were compared with those of non-GDM women with IFG or IGT. Maternal and neonatal outcomes were prospectively recorded for each group. RESULTS: GDM women with IFG, including isolated IFG and combined IFG+IGT, were significantly heavier, had higher leptin values and were more frequently multiparous than GDM women with isolated IGT. HOMA-IR was significantly higher when fasting glucose was impaired. There were no significant differences in maternal outcomes according to metabolic status. In addition, large for gestational age (LGA) neonates were significantly seen more often in the IFG group. Fasting glucose was significantly associated with LGA independently of BMI and 2-h OGTT glucose. The>5.1mmol/L cut-off value for fasting glucose was highly predictive of delivery of LGA infants. CONCLUSION: IFG in GDM women was associated with increases in BMI, fat mass and hepatic insulin resistance. Delivery of LGA neonates was more frequent when fasting glycaemia was increased during the third trimester of pregnancy, and was independent of BMI and 2-h OGTT glucose values.
