682 Could routine repeat cesarean delivery at 38 weeks gestation be a cost-effective alternative to 39 weeks: a cost-utility analysis Sherrine Ibrahim, Erika Werner, Sammy Tabbah, Sangini Sheth, Cynthia Shellhaas, Stephen Thung Ohio State University Wexner Medical Center, Maternal Fetal Medicine, Columbus, OH, The Johns Hopkins University School of Medicine, Gynecology and Obstetrics, Baltimore, MD OBJECTIVE: To determine if repeat cesarean delivery (CD) at the recommended 39 wks gestational age (GA) is cost-effective as compared to 38 wks GA. STUDY DESIGN: We developed a decision analysis model comparing the cost-utility of 2 strategies for women with a history of CD who plan on repeat surgery: 1) routine care with repeat CD at 39 wks GA, & 2) repeat CD at 38 wks GA. Assumptions included: 1) unremarkable pregnancy course at 38 wks GA with no immediate need for delivery, 2) modest increased risks of preeclampsia, fetal demise, uterine rupture with 39 wk delivery, 3) reduced risks of neonatal death, respiratory complications, & NICU admissions with 39 wk delivery, 4) proportion of neonates with immediate respiratory complications develop chronic respiratory disease. The primary outcome measure was the incremental cost-effectiveness ratio (ICER). Univariate sensitivity analysis & Monte Carlo simulations were performed. A costeffective strategy was defined as an ICER of $50,000/QALY gained. RESULTS: Our model demonstrates that for every 100,000 women planning repeat CD, routine delivery at 38 wks would cost an additional $19,183,000, improve overall health by 1029 QALYs; & result in an ICER of $18,642/QALY gained. We estimate that 38 wk delivery would prevent 50 perinatal losses but result in 156 additional offspring with chronic lung disease. These results were robust in the sensitivity analysis & only sensitive to the probability of fetal demise between 38 & 39 wks (if 0.02%). Monte Carlo simulation found that delivery at 38 wks was cost saving in 20% of simulations & cost-effective in 80% of simulations. CONCLUSION: Our findings support that elective repeat cesarean delivery at 38 wks GA may be cost-effective option when compared to 39 wks when including a variety of adverse outcomes that may develop between 38 & 39 wks.