Success of external cephalic version with immediate vs. delayed spinal anesthesia: A randomized controlled trial

Objective: The objective of this study was to determine whether there is a difference in the rate of successful external cephalic version (ECV) between patients receiving neuraxial analgesia a priori versus patients who only receive it if ECV initially fails. Study Design: We designed a randomized controlled trial comparing two groups with a 1:1 allocation scheme stratified by parity (nulliparous versus parous). In group 1, patients received spinal analgesia before attempting ECV, and in group 2, ECV was first attempted without spinal analgesia with reattempt after placing the spinal only if the first attempt failed. Non cephalic term patients (≥37 weeks) who presented to labor and delivery at Mount Sinai West for ECV were approached to enroll in the study. The primary outcome was the success of ECV with the null hypothesis being that there is no difference in the proportion of successful ECV between groups. Secondary outcomes included complications (bradycardias, non-reactive tracing, abruption, cesarean section, hypotension, transient bradycardia), pain scores, mode of delivery, Apgar scores and NICU admission. A total sample of 100 patients (50 in each group) provided 80% power to detect a 20% difference in the rate of successful ECV between the two groups. Results: Between April 2017 and April 2018, thirty-four patients were enrolled in the study (17 in each group). Demographic data and parity were similar in both groups. At that point, an increased rate of complications was observed in patients receiving spinal analgesia compared to those who did not (p=0.042) with a trend towards an increased rate of complications in the immediate versus the delayed group (p=0.082). Consequently, a decision was made to stop the study. While the power to determine significance of the primary outcome was not met, the rates of successful ECVs were equal in both groups (n=7, 41.2%). Conclusion: Despite an increasing breadth of literature supporting the use of neuraxial analgesia, one can consider attempting ECV without analgesia and only using analgesia if ECV initially fails. There is a similar rate of success in both groups and more complications in those receiving spinal analgesia.