Risk Factors for Gestational Diabetes Mellitus in Mainland China: A Systematic Review and Meta-Analysis

Objective: This study aimed to identify and evaluate risk factors associated with gestational diabetes mellitus (GDM) in mainland China. Methods: Eight electronic databases were searched for literature published from January 2010 until December 2023. Heterogeneity was quantified using I2. Data were pooled by fixed or random effects models and expressed as odds ratio and 95% confidence intervals. Results: A total of 69 observational studies with an overall sample size of 2,138,032 Chinese women and 219,303 patients with GDM were included in the analysis. After adjusting confounders, older maternal age (OR = 1.12, 95% CI: 1.09-1.15), maternal age >= 35 years (OR = 1.96, 95% CI: 1.74-2.21), higher pre-pregnancy body mass index (OR = 1.24, 95% CI: 1.17-1.32), pre-pregnancy overweight (OR = 1.78, 95% CI: 1.64-1.92) or obesity (OR 2.52, 95% CI: 2.06-3.08), family history of diabetes (OR = 1.85, 95% CI: 1.58-2.17), history of GDM (OR = 4.09, 95% CI: 2.13-7.82), and elevated levels of fasting plasma glucose (OR = 2.54, 95% CI: 2.13-3.01), hemoglobin (OR = 1.47, 95% CI: 1.14-1.89) and serum triglycerides (OR = 1.69, 95% CI: 1.31-2.16) in early pregnancy were associated with an increased risk of GDM in mainland China. But gravidity >= 2 (OR = 1.06, 95% CI: 0.89-1.27), conception by assisted reproductive technology analyses (OR = 1.54, 95% CI: 0.95-2.51) were not associated with GDM, and parity >= 1 (OR = 0.88, 95% CI: 0.82-0.94) was related to lower risk of GDM. In available unadjusted studies, history of abortion (OR = 1.34, 95% CI: 1.31-1.37) increased risk of GDM, non-Han ethnicity (OR = 0.78, 95% CI: 0.59-1.03) and high school or lower education level (OR1.09, 95% CI: 0.94-1.26) showed no correlation with GDM. Conclusion: The key risk factors for GDM in mainland China included older maternal age, maternal age >= 35 years, pre-pregnancy overweight or obesity, family history of diabetes, history of GDM, elevated levels of FPG, Hb, and serum TG in early pregnancy. Early identification and intervention for women at high risk should be performed to prevent the development of GDM.