Effect of Combined Gestational Diabetes Mellitus and Preeclampsia on Pregnancy Outcomes

Background: Gestational diabetes mellitus (GDM) and preeclampsia (PE) significantly increase the risk of adverse pregnancy outcomes. However, the effect on the risk of adverse pregnancy outcomes of GDM in combination with PE remains undetermined. Therefore, this study aimed to investigate the risk of adverse outcomes in pregnant women with GDM and PE. Methods: This retrospective cohort study was conducted at a single center. To explore the correlations between the occurrence of PE and adverse pregnancy outcomes, the enrolled population was divided into two groups: GDM and non-GDM. Risk factors associated with PE were analyzed using a binary logistic regression model. Results: This study comprised 27,181 pregnant women (5412 GDM cases and 21,769 non-GDM cases). The prevalence of PE was significantly higher in the GDM group than in the non-GDM group (p < 0.05). The presence of GDM, pre-pregnancy body mass index (pp-BMI) >24 kg/m2, and excessive gestational weight gain (GWG) were demonstrated to contribute to an increased risk of developing PE (p < 0.05). Pregnant women with GDM exhibited a significantly higher risk of preterm birth. Additionally, the risk of preterm birth, cesarean section, and fetal growth restriction increased further when PE occurred alongside GDM. Conclusions: Overall, pp-BMI >24 kg/m2 and excessive GWG were risk factors for PE. Pregnant women with GDM have a higher risk of developing PE, and co-occurrence of PE further increases the risk of adverse pregnancy outcomes. Therefore, attention and management of this population are needed during pregnancy.