Efficacy of a second external cephalic version (ECV) after a successful first external cephalic version with subsequent spontaneous reinversion to breech presentation: a retrospective cohort study

Objective: Determining the efficacy of performance of a second external cephalic version (ECV) following successful first ECV with subsequent spontaneous reinversion to breech presentation in reducing the rate of cesarean delivery (CD). Methods: Data were reviewed on healthy women with fetuses in breech presentation who underwent a first ECV after 36 weeks. Routine ultrasound study was performed at 39-week gestation, and a repeat ECV procedure was performed if the fetus had reverted to non-cephalic presentation. Obstetrical outcome measures were compared between women who underwent one successful ECV between 36- and 41-week gestation in which the fetus remained in cephalic presentation until labor and those who underwent a successful first ECV after which the fetus returned to breech and a second ECV was performed. The primary outcome was the rate of secondary CD during vaginal delivery in cephalic presentation; rate of successful second ECV was the secondary outcome. Results: Overall 250 women underwent one ECV attempt of which 169 (67%) were successful. Of them 28 reverted to breech presentation, all women underwent two attempts of which 21 (76%) were successful. A second successful ECV attempt was associated with a 33% incidence of a CD vs. 2.8% after one successful ECV in which the fetus remained in cephalic presentation. Conclusion: A second ECV after a successful first ECV with subsequent spontaneous reversion to breech presentation can be expected to be successful in 76% of cases but lead to CD in 33% of cases. Our findings can be used to support patient counseling and decision-making before second ECV attempt.