Significance of success rate of external cephalic versions and vaginal breech deliveries in counseling women with breech presentation at term.

Objective: To appreciate the role of success rates of external cephalic versions and breech deliveries, in order to assess the risk reduction in women with breech presentation at term.

Study Design: We reviewed the patient files of all women with breech presentation whom had an attempt of external cephalic version (ECV) at term. Most of the ECVs were performed under intravenous ritodrine infusion. All women had a trial of labor (TOL) as long as they did not meet one or more of the exclusion criteria of vaginal delivery. Success rates of ECV and TOL were assessed, and statistical analysis was performed by using the student t-test for continuous data, and the Chi-square and Fisher's exact tests for categorical data. Statistically significant differences required a P value of <0.05.

Results: Of all women with breech presentation at term and not in labor, who had no contraindication for an ECV, 164 consented and were included in the study. The success rate of ECV was 30% (22/74) and 67% (60/90) for nulliparae and multiparae, respectively. Multiparity was the only significant positive predicting variable for ECV success (OR=4.73, 95% CI 4.19-5.27, P=0.00001). Of all the women that underwent a successful ECV, 18/22 primiparae (82%), and 52/60 multiparae (87%) had a vaginal delivery, compared to only 52% of the primiparae and 63% of the multiparae that reached labor with a breech presentation. There were no significant perinatal complications except for one case of mild placental abruption. In the primiparous women, ECV decreased the chance of cesarean delivery by only 9% (P=0.2), compared to a 16% decrease in the multiparae (P=0.019).

Conclusions: When counseling women with breech presentation at term, complete information is needed for consent, and should take into account the success rate of ECVs and of vaginal breech deliveries in the specific center.