Optimal Timing of Delivery in Obese Women

Abstract

INTRODUCTION: Maternal obesity complicates over 20% of pregnancies in the United States and increases the risk of many adverse perinatal outcomes. However, limited data exist on the timing of delivery in such cases. The purpose of this study was to determine the optimal gestational age of delivery in an obese patient. METHODS: A decision-analytic model was created using TreeAge software to determine the optimal timing of delivery in a theoretical cohort of 100,000 singleton pregnancies in obese women. Model options ranged from delivery at 37 weeks to 41 weeks of gestation. Strategies involving expectant management until a later gestational age accounted for the probabilities of spontaneous delivery and intrauterine fetal demise at each successive week. Neonatal complications included permanent brachial plexus injury, cerebral palsy, and neonate death. All probability estimates were derived from the literature, and total quality-adjusted life-years were calculated. RESULTS: The lowest rates of neonate death and cerebral palsy were associated with delivery at 39 weeks of gestation, whereas rates of intrauterine fetal demise and brachial plexus injuries were lowest at earlier gestational ages (Table 1). Balancing these outcomes, the optimal strategy was delivery at 38 weeks of gestation, which maximized quality-adjusted life-years. Delivery at 38 weeks of gestation would prevent 203 intrauterine fetal demises compared with expectant management until 41 weeks of gestation. Sensitivity analysis found that 38 weeks of gestation remained the optimal strategy until the risks of neonate death and intrauterine fetal demise were 5.57-fold and 1.25-fold, respectively, our baseline assumptions.CONCLUSIONS: Weighing the risks of intrauterine fetal demise against the risks of neonate death and significant neonatal morbidities, the ideal gestational age to deliver obese women is 38 weeks.