Correlation Between Blood Glucose Variability Indices Using Continuous Glucose Monitoring in Gestational Diabetes Patients and Abnormal Glucose Levels 42 Days Postpartum

<b>Objective:</b> This study was aimed at analyzing the impact of blood glucose variability (GV) in gestational diabetes mellitus (GDM) patients on glucose outcomes 42 days postpartum and pregnancy outcomes. Additionally, it explored differences between various GV indices and evaluated their predictive values. <b>Methods:</b> This retrospective study included 75 pregnant women diagnosed with GDM. Continuous glucose monitoring (CGM) was initiated postdiagnosis, and outcomes were followed up. Oral glucose tolerance tests (OGTTs) were conducted 42 days postpartum to assess glucose response. <b>Results:</b> A total of 75 patients were included, among whom 8 (10.67%) exhibited impaired fasting glucose (IFG) and 7 (9.33%) impaired glucose tolerance (IGT) in the 42-day postpartum OGTT. No cases of diabetes were diagnosed. The results of the postpartum OGTT were significantly correlated with various GV indexes. In multivariate analysis, LBGI (OR: 1.437; 95% CI: 1.015-2.035; <i>p</i> = 0.041), <i>M</i> value (OR: 1.215; 95% CI: 1.030-1.434; <i>p</i> = 0.021), and TBR% (OR: 1.138; 95% CI: 1.020-1.271; <i>p</i> = 0.021) independently influenced IFG. Receiver operating characteristic (ROC) analysis indicated areas under the curve (AUCs) of 0.877 (95% CI: 0.760~0.994), 0.853 (95% CI: 0.730~0.975), 0.869 (95% CI: 0.748~0.991), and 0.793 (95% CI: 0.622~0.963) of IFG prediction model performance of TBR%, LBGI, <i>M</i> value, and HbA1c% combined with age, BMI, and family history of diabetes, respectively. <b>Conclusion:</b> Blood GV is an independent factor influencing IFG 42 days postpartum in GDM women, especially with hypoglycemia. It can increase the predictive efficiency of the postpartum abnormal blood glucose prediction model. <b>Trial Registration:</b> Chinese Clinical Trial Registry number: ChiCTR2100054833.