Project Summary/Abstract Cesarean delivery (CD) is the most common inpatient surgery in the US, accounting for nearly one third of births annually. Numerous organizations have targeted reducing the CD rate as an important public health goal; however, identifying interventions to achieve this goal has proven challenging. In addition, determining when the benefits of delivery outweigh those of ongoing pregnancy is one of the central dilemmas of obstetric care, and defining the optimal timing of delivery from the perspective of the mother and the neonate has been a topic of much debate. Delivery at 39 weeks has been proposed as optimal for the neonate, but it has also been suggested that the widespread use of induction has contributed to the high rate of cesarean deliveries. In addition, the appropriateness of intervening in pregnancy without a clear medical indication is highly controversial. The recent presentation of the findings of the ARRIVE trial, a randomized trial of induction of labor at 39 weeks versus expectant management in more than 6100 nulliparous women, is poised to impact this calculus significantly. In this large multicenter study, elective induction of labor at 39 weeks was associated with a decrease in cesarean rate, a decrease in preeclampsia and a decrease in need for neonatal respiratory support without a statistically significant difference in adverse perinatal outcomes. Given the difficulty in identifying interventions to decrease the cesarean rate and improve maternal outcomes, the potential implications of these findings on obstetric practice are significant. However, while the clinical outcomes associated with elective induction at 39 weeks are compelling, there is much that is unknown about how patients and providers would view such a significant change in practice. In anticipation of clinical guidelines that are likely to recommend the offer of induction of labor at 39 weeks in view of the new data, it is critical that we gain a nuanced understanding of how these stakeholders view the prospect of a routine offer of induction at 39 weeks. In addition, given the potential complexity involved in this discussion as well as the significant population of women who will face this decision, it is an ideal target for a decision tool to improve efficiency and optimize the incorporation of informed patient preferences in this decision. The proposed study seeks 1) to conduct formative research among pregnant women and prenatal care providers regarding how they would view the offer of elective induction of labor at 39 weeks, 2) to use this information in the creation of a prototype decision tool regarding elective induction, and 3) to conduct a pilot study of feasibility and acceptability of the tool. Our ultimate goal is to conduct a randomized trial of this decision support tool to assess its impact on induction rates, cesarean delivery rates, resource utilization, decision quality, and patient satisfaction with the labor and delivery process. Page 1