Does Mode of Terbutaline Administration Improve Success of External Cephalic Version? [34I

Abstract

INTRODUCTION: There is a high rate of cesarean delivery (CD) for breech presentation and external cephalic version (ECV) is a means to allow for vaginal delivery and thus reduce CD. Our primary objective was to compare the success rate of ECV with subcutaneous versus intravenous (IV) terbutaline. METHODS: This was a retrospective cohort of women with singleton fetuses ≥ 36 weeks of gestation undergoing ECV at our institution from May 2007-February 2018. Our protocol from 2007-2013 included a single dose of subcutaneous terbutaline (0.25 mg) followed by ECV. From March 2013 until February 2018, our protocol was a single dose of intravenous terbutaline (0.25 mg) prior to ECV attempt. Statistical analysis included Student t test, Mann-Whitney U, chi-squared and Fisher exact as appropriate. Logistic regression was used to determine which factors affected success. RESULTS: Of the 283 patients who underwent an attempted ECV, 111 received subcutaneous and 172 received IV terbutaline. The overall success rate was 65%. The success rate was 71% in the subcutaneous group vs 61.6% in the IV group (p=0.183). Lateral position of the fetal spine (p=0.02) and increasing AFI (p<0.005) were found to be predictive of success by logistic regression analysis. Maternal age, BMI, parity, placenta location, gestational age, head position, breech time and neonatal birth weight did not influence success. CONCLUSION: We did not find a difference in success rate of ECV when terbutaline was administered subcutaneously versus intravenously. We found that lateral fetal spine position and increasing AFI were independently associated with version success.