To evaluate a possible correlation between a new variable—persistent breech presentation—and the success rate of external cephalic version (ECV).
This was a retrospective study of ECVs performed from January 2008 through January 2019 in an Israeli tertiary care hospital. The study group included all pregnant women who underwent an ECV at or beyond 37 weeks of gestation. Persistent breech presentation was defined as persistent breech presentation during all ultrasound examinations performed between the anatomy scan at mid-pregnancy and the gestational week when ECV was attempted. Women in whom cephalic presentation was documented at least once on these ultrasound examinations were defined as not having persistent breech presentation. The primary outcome was defined as the success rate of ECV, and the secondary outcome was defined as the mode of delivery after a successful ECV.
We identified 1,271 women with breech presentation during the study period. They had undergone median of five (range 2–7) ultrasound examinations. External cephalic version was attempted in 684 women (53.8%), with a success rate of 61.5%. External cephalic version succeeded in 19.6% of those with persistent breech presentation (44/224) compared with 82.0% (377/460) of those without persistent breech presentation (P<.001). Ultimately, women with persistent breech presentation and successful ECV experienced a lower rate of vaginal delivery (27.3% vs 79%, P<.001), and a higher rate of instrumental (29% vs 13%, P<.001) and cesarean deliveries (43% vs 7%, P<.001) compared with the nonpersistent breech presentation group. The rate of noninstrumental vaginal delivery among women with persistent breech presentation, regardless of ECV, was 5.4%.
Women with persistent breech presentation experienced a high rate of ECV failure and a low rate of spontaneous vaginal delivery.