Factors Influencing the Success of Breech External Cephalic Version and Their Impact on Delivery Mode and Maternal-Neonatal Outcomes.

Abstract

Objectives: This prospective cohort study aimed to identify key factors influencing the success rate of external cephalic version (ECV) and to evaluate its impact on the mode of delivery and maternal-neonatal outcomes.

Design: A prospective cohort study was conducted. Participants/Materials: The study enrolled 62 pregnant women with singleton breech presentations at or beyond 37 weeks of gestation who consented to undergo ECV. A convenience sample of 12 women with cephalic presentations was also enrolled as a control group for outcome comparison.

Setting: The study was conducted at the Department of Obstetrics and Child Health Hospital, Jinniu District Maternal and Child Health Hospital, Chengdu, China.

Methods: Participants were divided into ECV success (n = 51) and failure (n = 11) groups based on procedural outcome. Baseline characteristics were compared, and predictors of ECV success were analyzed using univariable logistic regression. Maternal and neonatal outcomes were compared between the success group and the control group.

Results: Five independent predictors of ECV success were identified: lower maternal body mass index (BMI) at delivery (odds ratio [OR] = 0.816, 95% confidence interval [CI]: 0.662-0.991; p = 0.042), prior spontaneous vaginal delivery (OR = 8.250, 95% CI: 1.879-58.080; p = 0.012), non-posterior placental location (OR = 0.171, 95% CI: 0.034-0.678; p = 0.017), higher amniotic fluid index (OR = 1.442, 95% CI: 1.053-2.185; p = 0.048), and fewer ECV attempts (OR = 0.174, 95% CI: 0.059-0.375; p = 0.001). The ECV success group had a significantly higher vaginal delivery rate (81% vs. 0%; p = 0.012) and a lower cesarean delivery rate (19% vs. 100%) compared to the failure group. Neonates in the success group exhibited higher birth weights (3,266.4 ± 352.54 g vs. 3,063.2 ± 202.93 g; p = 0.017). Outcomes in the success group were comparable to the cephalic-presentation control group, except for a higher rate of labor induction (33.3% vs. 0%, p = 0.050).

Limitations: The main limitations of this study include its modest sample size, single-center design, and the lack of long-term follow-up data on maternal and neonatal outcomes post-ECV.

Conclusions: ECV is an effective intervention for reducing cesarean delivery rates in breech presentations. Success is associated with lower maternal BMI, a history of vaginal delivery, favorable placental location, adequate amniotic fluid, and fewer procedural attempts. These findings support the integration of patient-specific factors into clinical protocols to optimize ECV success and improve perinatal outcomes.