The Early External Cephalic Version (ECV) 2 Trial: an international multicentre randomised controlled trial of timing of ECV for breech pregnancies

Abstract

Objective: To investigate whether initiating external cephalic version (ECV) earlier in pregnancy might increase the rate of successful ECV procedures, and be more effective in decreasing the rate of non-cephalic presentation at birth and of caesarean section.

Design: An unblinded multicentred randomised controlled trial.

Setting: A total of 1543 women were randomised from 68 centres in 21 countries.

Population: Women with a singleton breech fetus at a gestational age of 33(0/7) weeks (231 days) to 35(6/7) weeks (251 days) of gestation were included.

Methods: Participants were randomly assigned to having a first ECV procedure between the gestational ages of 34(0/7) (238 days) and 35(6/7) weeks of gestation (early ECV group) or at or after 37(0/7) (259 days) weeks of gestation (delayed ECV group).

Main outcome measures: The primary outcome was the rate of caesarean section; the secondary outcome was the rate of preterm birth.

Results: Fewer fetuses were in a non-cephalic presentation at birth in the early ECV group (314/765 [41.1%] versus 377/768 [49.1%] in the delayed ECV group; relative risk [RR] 0.84, 95% CI 0.75, 0.94, P=0.002). There were no differences in rates of caesarean section (398/765 [52.0%] versus 430/768 [56.0%]; RR 0.93, 95% CI 0.85, 1.02, P=0.12) or in risk of preterm birth (50/765 [6.5%] versus 34/768 [4.4%]; RR 1.48, 95% CI 0.97, 2.26, P=0.07) between groups.

Conclusion: External cephalic version at 34-35 weeks versus 37 or more weeks of gestation increases the likelihood of cephalic presentation at birth but does not reduce the rate of caesarean section and may increase the rate of preterm birth.