Success rates of early versus late initiation of external cephalic version

To determine optimum timing of external cephalic version (ECV).

A retrospective cohort study was conducted at a tertiary hospital in Israel between February 1, 2016, and July 1, 2017. Healthy primiparous women with breech presentation were offered either early ECV (35-36 weeks; n=54) or late ECV (37-38 weeks; n=106). Group assignment was according to the patient's preference and physician availability. The primary outcome was the rate of cephalic presentation at delivery. Secondary outcomes included rate of cesarean delivery, presentation of fetus after the first and last ECVs, and serious fetal complications.

The incidence of undergoing more than two ECV attempts was 18.5% in the early ECV group and 5.6% in the late ECV group (P=0.039). The incidence of cephalic presentation after the first ECV was 72.2% in the early ECV group versus 66.0% in the late ECV group (P=0.048). By contrast, no statistically significant between-group differences were found for presentation at delivery or rate of cesarean delivery. The other outcomes were also similar.

Early initiation of ECV among primiparous women increased the chance of immediate cephalic presentation; however, it had no effect on presentation at delivery or cesarean delivery rate.