Hypoglycemia during the oral glucose tolerance test in pregnancy—maternal characteristics and neonatal outcomes

Objective: To evaluate maternal and neonatal outcomes in pregnancies complicated by hypoglycemia on 100-g oral glucose tolerance test (OGTT). Methods: A retrospective cohort analysis of all live-born deliveries in a single medical center during 2018 and 2019 with available OGTT results and birth outcomes. Preterm deliveries (<34 weeks), multiple pregnancies and major anomalies were excluded. Hypoglycemia during OGTT was defined as at least one glucose value below 60 mg/dl. Maternal characteristics and perinatal outcomes were compared between three groups: Hypoglycemia on OGTT, Normal OGTT and Abnormal OGTT. Univariate followed by multivariate analyses were used to control for confounders. Results: Overall, 2079 women were entered into the analysis. Of these, 216 (10.4%) had at least one hypoglycemic value, 1072 (51.6%) had normal OGTTs and 791 (38%) abnormal OGTTs. Hypoglycemia in OGTT was more prevalent in multiparous women and was associated with fetal male gender. Absolute birth weight, low birth weight and small for gestational age differed between groups; however, there was no difference between groups in overall birth weight centiles (60.1 ± 26.8 versus 63 ± 26 versus 60.9 ± 27; P > 0.05). Following adjustment of confounders, hypoglycemia was not associated with rates of low birth weight or small for gestational age (P < 0.05). There were no other differences in perinatal outcomes between groups. Conclusion: Hypoglycemia in OGTT is not associated with maternal or neonatal adverse outcomes.