# Safety of vaginal breech delivery following an unsuccessful external cephalic version: a comparative study

## TL;DR

This study found that attempting vaginal breech delivery after a failed external cephalic version does not increase risks for mothers or babies.

## Contribution

The study provides evidence that failed ECV does not worsen outcomes for breech vaginal deliveries.

## Key findings

- Failed ECV does not reduce successful vaginal delivery rates for breech presentations.
- Vertex-ECV group had higher vaginal delivery rates and fewer neonatal complications.
- No significant adverse maternal or neonatal outcomes in the Breech-failed-ECV group.

## Abstract

To determine whether patients undergoing a trial of labor with a breech presentation following a failed attempt of external cephalic version (ECV) are at increased risk of adverse maternal and neonatal outcomes.

This retrospective cohort study was conducted at a single university-affiliated medical center. The study group comprised women with singleton pregnancies at term, categorized into three groups: those who underwent a failed external cephalic version (ECV) and subsequently attempted a trial of breech delivery (Breech-failed-ECV group), those who attempted an assisted vaginal breech delivery without a prior ECV attempt (Breech-no-ECV group), and those with vertex presentation following a successful ECV (Vertex-ECV). The primary outcome measured was the mode of delivery. Secondary outcomes included adverse maternal and neonatal outcomes.

The study group consisted of 229 patients who attempted a vaginal delivery during the study period following a diagnosis of non-cephalic presentation at term. There were 42 women in the Breech failed-ECV group, 102 in the Breech-no-ECV group, and 85 in the Vertex-ECV group. Among patients undergoing a trial of labor with a breech presentation, there were no significant differences in successful vaginal delivery rates between those who had an attempted ECV and those who did not (80.39% vs. 80.95%, p > 0.05), nor in the rate of adverse maternal or neonatal outcomes between the groups. However, the Vertex-ECV were more likely to have a vaginal delivery (91.78 vs 80.56%, p = 0.03) and less likely to experience adverse neonatal outcomes, including meconium-stained amniotic fluid, non-reassuring fetal heart rate (NRFHR), compared to those who underwent labor with a breech presentation (p < 0.05).

A failed external cephalic version does not adversely affect maternal or neonatal outcomes in patients undergoing a trial of labor with a breech presentation and meet the criteria of our study.

The online version contains supplementary material available at 10.1007/s00404-024-07873-9.