Gestational Weight Gain in Obese Patients and Adverse Pregnancy Events

Abstract

Objectives: To examine pre-pregnancy obesity and gestational weight gain as predictors for adverse pregnancy outcomes in a predominantly non-white obstetric resident clinic population. Methods: Prenatal charts for patients with pre-pregnancy obesity cared for at our resident clinic from January 1, 2008 through December 31, 2010 were reviewed. Adverse maternal outcomes were grouped into a “Composite Morbidity Index” (CMI-M) and included gestational diabetes, gestational hypertension, preeclampsia, superimposed preeclampsia, dystocia, operative delivery, Cesarean section for arrest disorders, wound infection and disruption, and thromboembolic events. Fetal events, similarly categorized into a composite adverse fetal index (CMI-F), included macrosomia, Apgar at 5 minutes (≤3), NICU admission, congenital anomalies and intrauterine fetal demise. Results: 627 women with a singleton pregnancy and a pre-pregnancy body mass index (BMI) of 30 and greater were included in the analysis. As measured by the composite morbidity index, women with Class III obesity at their first prenatal visit were more likely to have at least one or more maternal and fetal complications compared to women with Class II or Class I obesity. For adverse maternal outcomes (CMI-M), 40.2%, 33.8%, and 27.4% of women within each respective obesity class experienced an adverse event (p = 0.027). Applying the CMI-F, fetal complications were observed in 28.2%, 18%, and 13.9% of Class III, II, and I obesity (p = 0.003). Total gestational weight gain per week was significantly greater for patients with one or more maternal complications (p = 0.045). Conclusion: Among an obese, resident clinic population comprised primarily of women of ethnic minorities, pre-pregnancy body mass index was the strongest indicator for adverse maternal and fetal outcomes.