The Effect of Single/Multiple Abnormal Values in the 75 g OGTT on Maternal and Neonatal Outcomes in GDM Diagnosis

INTRODUCTION: Although early diagnosis and management of GDM aims to reduce adverse outcomes for the mother and newborn, the prognostic value of the number of positive values in the 75 g OGTT remains unclear. This study investigates whether single, double, or triple positive values in the 75 g OGTT are associated with maternal and neonatal outcomes in women diagnosed with GDM.
METHODS: This retrospective, single-center study included 120 pregnant women diagnosed with GDM according to IADPSG criteria based on a 75 g OGTT after an 8-hour fast between April 2024 and December 2025.Groups were defined by the number of abnormal values in the 75g OGTT (fasting ≥92 mg/dL, 1-hour ≥180 mg/dL, 2-hour ≥153 mg/dL): single (one abnormal), double (two), or triple (all three). The data collected included age, number of pregnancies, number of births, gestational age at delivery, HbA1c, treatment method, birth weight, Apgar scores, NICU admission, neonatal hypoglycemia, hyperbilirubinemia, and macrosomia.
RESULTS: HbA1c was higher in Group 3 (mean difference vs. Group 1: 1.82 ± 0.32, p<0.001); cesarean rates were 95% in Group 1 vs. 60% in Group 3 (absolute difference: 35%, p=0.024). Macrosomia, Apgar scores at 1 and 5 minutes, admission to the NICU, neonatal hypoglycemia, and hyperbilirubinemia, among other neonatal outcomes, did not differ significantly between groups.
DISCUSSION AND CONCLUSION: Among pregnant women diagnosed with GDM using a 75 g OGTT, increased positive values were associated with higher maternal HbA1c and increased likelihood of cesarean delivery, but this did not lead to consistent differences in neonatal morbidity.

Keywords: Gestational diabetes mellitus, Oral glucose tolerance test, Neonatal outcome