Objective To investigate the risk factors of pre-gestational diabetes mellitus (PGDM) among women of childbearing age, and provide a scientific basis for PGDM prevention and control. Methods A retrospective analysis was conducted on clinical data from 2,034 pregnant women who underwent prenatal care at Maternity and Child Health Care of Guangxi Zhuang Autonomous Region from 2019 to 2021. Participants were divided into PGDM and non-PGDM groups. Risk factors for PGDM were analyzed using univariate analysis, multivariate logistic regression, and restricted cubic spline analysis. Results Among 2,034 participants, 47 were diagnosed with PGDM, yielding an incidence rate of 2.31%. Univariate analysis revealed that the PGDM group had higher mean age, pre-pregnancy BMI, median parity, and proportion of first-degree relatives with diabetes, but lower mean height compared to the non-PGDM group (all P<0.05). Multivariate logistic regression identified overweight/obesity before pregnancy (OR=2.39), short stature (<155.0 cm, OR=2.49), age ≥30 years (OR=2.49), and family history of diabetes in first-degree relatives (OR=2.44) as independent risk factors for PGDM (all P<0.05). Restricted cubic spline analysis demonstrated linear positive correlations of age and BMI with PGDM risk, and a linear negative correlation for height (all P<0.05). Conclusion Overweight/obesity before pregnancy, family history of diabetes in first-degree relatives, short stature (<155.0 cm), and older maternal age (≥30 years) are significant risk factors for PGDM. Public health measures, such as promoting age-appropriate childbearing and pre-pregnancy weight management, should be prioritized to reduce PGDM incidence