Effects of Prepregnancy Body Mass Index, Weight Gain, and Gestational Diabetes Mellitus on Pregnancy Outcomes: A Population-Based Study in Xiamen, China, 2011-2018

Background: It is unclear that how prepregnancy body mass index (BMI), gestational weight gain (GWG), and gestational diabetes mellitus (GDM) affect pregnancy outcomes in -China. Thus, we explored how BMI, GWG, and GDM affect the risks of adverse pregnancy outcomes. Methods: We performed a retrospective, population-based study included all births in Xiamen, China, 2011-2018. Demographic data and pregnancy outcomes of 73,498 women were acquired from the Medical Birth Registry of Xiamen. Women were categorized into groups on prepregnancy BMI and GWG in order to assess the risk of pregnancy outcomes. Multivariable logistic regression was performed to evaluate risk factors. Results: Overall, 6,982 (9.37%) women were obese, and 8,874 (12.07%) women were overweight. Obese women are more vulnerable to cesarean delivery, preterm birth, large-for-gestational age (LGA), and macrosomia (crude OR [cOR] 2.00, 1.89-2.12; 1.35, 1.20-1.51; 2.12, 1.99-2.26; 2.53, 2.25-2.86, respectively, adjusted ORs 1.73, 1.62-1.84; 1.25, 1.10-1.42; 2.03, 1.90-2.18; 2.77, 2.44-3.16, respectively). Similar results were observed in overweight women (cORs 1.49, 1.42-1.57; 1.02, 0.91-1.15; 1.60, 1.50-1.70; 2.01, 1.78-2.26, respectively). Furthermore, women who gain weight in excessive group were 1.43, 2.06, and 2.16 times to deliver cesarean, LGA, and macrosomia, respectively. Additionally, GDM women were easily subjected to cesarean section, preterm birth, LGA, low birth weight, and macrosamia (cORs 1.52, 1.55, 1.52, 1.37, 1.27, respectively). Conclusions: Obesity prior to pregnancy, excessive GWG, and GDM were all associated with increased odds of cesarean, LGA, and macrosomia. Blood glucose and weight control before and during pregnancy are needed that may reduce the complications of pregnancy.