Impact of obesity on maternal and neonatal outcomes in insulin-resistant pregnancy

Objective To determine the impact of obesity on pregnancies complicated by insulin resistance. Study Design Secondary analysis of prospective cohort of women with gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (DM). The exclusion criteria were type 1 DM, multiple gestation, fetal anomalies, unknown prepregnancy, and body mass index (BMI). Primary maternal outcome was a composite of any of the following: severe preeclampsia, eclampsia, third- to fourth-degree laceration, readmission, wound infection, or antepartum hospitalization. Primary neonatal outcome was a composite of any of the following: hypoglycemia, preterm delivery, admission to level 3 nursery, oxygen requirement > 6 hours after birth, shoulder dystocia, 5-minute Apgar ≤3, cord pH < 7.0, and cord base excess < -12 mmol/L. Obese women (BMI ≥30.0 kg/m²) were compared with nonobese women (BMI < 30.0 kg/m2). Results Of 356 subjects with DM, 233 (66%) were obese. Obese women were not at further increased risk of the composite maternal outcome (adjusted odds ratio [AOR] = 0.68, 95% confidence interval [CI] = 0.43-1.09), the composite neonatal outcome (AOR = 0.76, 95% CI = 0.48-1.21), or cesarean (58.8 vs. 52.9%, p = 0.28, AOR = 1.47, 95% CI = 0.91-2.39). Conclusion We did not find evidence that obesity worsened pregnancy outcomes in women with GDM and type 2 DM, suggesting that obese women may not require more stringent antepartum treatment strategies.