This study aims to assess maternal and neonatal outcomes in pregnancies complicated by hypoglycemia during the 50-g oral glucose challenge test (GCT).

This is a retrospective cohort analysis of all live births at a single medical center between 2015 and 2019 with available 50-g GCT results and birth outcomes. Hypoglycemia during 50-g GCT was defined as a glucose value below 88 mg/dl at the first-hour glucose result. Maternal characteristics and perinatal outcomes were compared between two groups: hypoglycemia at 50-g GCT (group 1) and normal 50-g GCT (group 2).

A total of 535 nulliparous cases were included. No significant differences were observed in delivery week and day, Apgar scores at 1 and 5 min, mode of delivery, fetal sex, and admission to the neonatal intensive care unit (p > 0.05). While no significant differences were found in prenatal biparietal diameter, abdominal circumference, and femur length (p value, 0.486, 0.297, and 0.106, respectively), birth weight was significantly lower in the hypoglycemic group (3222 ± 566 vs. 3340 ± 410, p < 0.001).

Hypoglycemia during a 50-g GCT is significantly associated with lower birth weight. Pregnant women experiencing hypoglycemia during the 50-g GCT at 24–28 weeks' gestation should be closely monitored, possibly classified as high-risk pregnancies, considering the potential for unfavorable perinatal outcomes.