The combined impact of time in range and HOMA-IR on neonatal outcomes in gestational diabetes mellitus: A retrospective cohort study

Time in range (TIR) derived from continuous glucose monitoring and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) are independent predictors of maternal and neonatal outcomes in gestational diabetes mellitus (GDM). However, their combined effect on neonatal outcomes remains unclear. This study aimed to investigate the joint influence of TIR and HOMA-IR on neonatal outcomes in GDM patients. In this retrospective cohort study, 166 women with GDM were categorized into 4 groups based on TIR levels (cutoff: 90%) and HOMA-IR (cutoff: cohort median): Group A (high-TIR/low-IR), Group B (high-TIR/high-IR), Group C (low-TIR/low-IR), and Group D (low-TIR/high-IR). HOMA-IR was calculated at "24 to 28 weeks' gestation" gestation using fasting plasma glucose and insulin levels obtained during the oral glucose tolerance test. Neonatal complications, including hypoglycemia, macrosomia, and hyperbilirubinemia, were compared across groups. Compared with Group A (high-TIR/low-IR), Group D (low-TIR/high-IR) demonstrated the highest risk for adverse neonatal outcomes, with significantly higher incidence of neonatal hypoglycemia (OR: 4.52, 95% CI: 1.89-10.78) and macrosomia (OR: 3.45, 95% CI: 1.45-8.19), along with higher mean neonatal bilirubin levels (10.97 ± 1.72 mg/dL vs 8.99 ± 2.09 mg/dL, P < .001). Poor glycemic control (low TIR) combined with significant insulin resistance (high HOMA-IR) identifies a subgroup of GDM patients at the highest risk for adverse neonatal outcomes. The joint assessment of TIR and HOMA-IR may facilitate precise risk stratification and personalized management in clinical practice.