A retrospective study of maternal and neonatal outcomes in overweight and obese women with gestational diabetes mellitus

In pregnant women, obesity is a risk factor for multiple adverse pregnancy outcomes, including gestational diabetes mellitus (GDM), preeclampsia, and preterm birth. The aim of this study was to determine the effects of pre-pregnancy body mass index (BMI) on maternal and neonatal outcomes in women with GDM. A retrospective study of 5010 patients with GDM in 11 provinces in China was performed in 2011. Participants were divided into three groups based on BMI as follows: a normal weight group (BMI 18.5–23.9 kg/m²), an overweight group (BMI 24–27.9 kg/m²), and an obese group (BMI ≥28.0 kg/m²). Maternal baseline characteristics and pregnancy and neonatal outcomes were compared between the groups. Multiple logistic regression analysis was used to explore the relationships between BMI and the risk of adverse outcomes. Of the 5010 GDM patients, 2879 subjects were from north China and 2131 were from south China. Women in the normal weight group gained more weight during pregnancy compared with the overweight and obese GDM patients. Women in the overweight and obese groups had increased odds of hypertension during pregnancy (adjusted odds ratio (AOR) = 1.50, 95 % confidence interval (CI) = 1.31–1.76 and AOR = 2.12, 95 % CI = 1.84–3.16). The AORs for macrosomia in the overweight and obese groups were 1.46 (95 % CI = 1.16–1.69) and 1.94 (95 % CI = 1.31–2.98), respectively. The relative risk of delivering a baby with an Apgar score <7 at 5 min was significantly higher in women who were obese (AOR = 2.11, 95 % CI = 1.26–2.85) before pregnancy compared with normal weight women. Compared with the normal weight subjects, the incidence of cesarean section and emergency cesarean section among overweight and obese women with GDM was significantly higher (P < 0.001). Overall, overweight and obese women with GDM have an increased risk of adverse outcomes, including hypertension during pregnancy, macrosomic infants, infants with low Apgar scores, and the need for an emergency cesarean section. More attention should be paid to GDM women who are obese because they are at risk for multiple adverse outcomes.