The role of pre-pregnancy overweight in gestational diabetes, hypertension, and macrosomia: a retrospective study.

Purpose: Adverse pregnancy outcomes, including gestational diabetes mellitus (GDM), gestational hypertension (GHp), macrosomia, preterm birth, and low birth weight, pose significant risks to maternal and neonatal health. Pre-pregnancy overweight is a modifiable risk factor for these outcomes. However, comprehensive analyses of multiple adverse outcomes and their dose-response relationships with pre-pregnancy body mass index (BMI) remain limited. Methods: This retrospective cohort study included 748 women with singleton pregnancies who delivered at Yuyao Maternal and Child Health Hospital from January 1, 2022, to December 31, 2022. Participants were categorized into normal-weight and overweight groups based on pre-pregnancy BMI. Logistic regression models were used to evaluate associations between overweight and adverse pregnancy outcomes, adjusting for confounding variables. Restricted cubic spline (RCS) regression was employed to investigate dose-response relationships between BMI and pregnancy outcomes. Results: Pre-pregnancy overweight was significantly associated with higher risks of GDM (adjusted OR = 3.122, 95% CI [1.754-5.557], p < 0.001), GHp (adjusted OR = 2.864, 95% CI [1.566-5.239], p = 0.001), and macrosomia (adjusted OR = 2.119, 95% CI [1.076-4.173], p = 0.030). No significant associations were observed with preterm birth or low birth weight. RCS analysis showed no evidence of nonlinear relationships, indicating that the risk of adverse outcomes increased linearly with BMI. Conclusion: Pre-pregnancy overweight is a significant modifiable risk factor for adverse maternal and neonatal outcomes, particularly GDM, GHp, and macrosomia. These findings underscore the importance of integrating BMI monitoring and personalized weight management strategies into pre-pregnancy care programs to mitigate risks and improve maternal and neonatal health outcomes.