External cephalic version for breech presentation before term

External cephalic version (ECV) of the breech fetus at term (after 37 weeks) has been shown to be effective in reducing the number of breech presentations and caesarean sections, but the rates of success are relatively low. This review examines studies initiating ECV prior to term (before 37 weeks' gestation).

To assess the effectiveness of a policy of beginning ECV before term (before 37 weeks' gestation) for breech presentation on fetal presentation at birth, method of delivery, and the rate of preterm birth, perinatal morbidity, stillbirth or neonatal mortality.

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (April 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2005), MEDLINE (1965 to April 2005), EMBASE (1988 to April 2005), and Controlled Clinical Trials randomised controlled trials registry (April 2005).

Randomised trials of ECV beginning before term (before 37 weeks' gestation) compared with a control group in women with breech presentation before term.

Two review authors independently assessed eligibility and trial quality and extracted data.

Three studies are included. One study reported on ECV that was undertaken and completed before 37 weeks' gestation compared to no ECV. No difference was found in the rate of non-cephalic presentation at birth. One study reported on a policy of ECV that was initiated before term (33 weeks) and up until 40 weeks' gestation and which could be repeated up until delivery compared to no ECV. This study showed a decrease in the rate of non-cephalic presentation at birth (relative risk 0.59, 95% confidence interval 0.45 to 0.77). One study reported on ECV started at between 34 to 35 weeks' gestation compared to beginning at 37 to 38 weeks' gestation. Although findings were not statistically significant, a 9.5% decrease in the rate of non-cephalic presentation at birth and a 7% decrease in the caesarean section rate were reported when ECV was started early.

Compared with no ECV attempt, ECV commenced before term reduces non-cephalic births. Compared with ECV at term, beginning ECV at between 34 to 35 weeks may have some benefit in terms of decreasing the rate of non-cephalic presentation, and caesarean section. Further trials are needed to confirm this finding and to rule out increased rates of preterm birth, or other adverse perinatal outcomes. A large pragmatic trial is ongoing (www.utoronto.ca/miru/eecv2).