Solely Elevated Fasting Glucose Level In Glucose Tolerance Test: A Dilemma For Diagnosis of GDM

Objective To evaluate and compare obstetric and neonatal outcomes of pregnant women with solely elevated fasting glucose levels who were diagnosed with gestational diabetes mellitus (GDM) using the 75-gram OGTT approach with those who were not diagnosed with GDM using the 100-gram OGTT approach. Methods This retrospective study was conducted at Etlik City Hospital, Ankara, Türkiye, and included pregnant women who underwent either a 75-gram or a 100-gram OGTT between January 2023 and March 2025 between 24 and 32 weeks of gestation. The participants were categorized into three groups: Group 1; with a diagnosis of GDM based on solely elevated fasting blood glucose during the 75-gram OGTT. Group 2; not diagnosed with GDM despite elevated fasting glucose during the 100-gram OGTT. Group 3; diagnosed with GDM due to an otherwise positive value in the 75-gram OGTT approach except for the solely fasting glucose level. Obstetric and neonatal outcomes, diabetes parameters, insulin therapy requirement,and birth characteristics were analysed and compared between groups. Results Fasting glucose levels were significantly higher in group 2 compared to the other groups (p = 0.001). No patient in group 1 required insulin, while 11.8% of group 2 and 27.3% of group 3 required insulin therapy (p = 0.025). Neonatal blood glucose levels were significantly lower in group 3 compared to group 2 (p = 0.006). Requirement for insulin therapy, polyhydramnios, preterm birth, LGA, caesarean section, admission of the newborn to the intensive care unit and the duration of admission to the intensive care unit were comparable between group 2 and group 3. Conclusion Solely elevated fasting glucose levels, at diagnostic test for GDM, are associated with adverse obstetric and neonatal outcomes. These findings support the inclusion of solely elevated fasting glucose level as a diagnostic criterion for GDM and point to the need for standardised treatment of these patients, regardless of the OGTT method used.