A randomized trial of external cephalic version with tocolysis in late pregnancy.

The effect of external version under tocolysis with intravenous ritodrine during the 37th week of gestation was studied in a prospective randomized trial comprising 130 consecutive women with a fetus in breech presentation. Version was successful in 41% of the patients, all of whom had a cephalic vaginal delivery. Of the 56 women in the control group in whom version was not attempted; 8 (14%) converted to the vertex presentation spontaneously. Failure of version was significantly correlated with primiparity, location of the placenta on the anterior uterine wall, and maternal weight. The caesarean section rate was significantly lower in the version group (27%) than in the control group (46%) (P less than 0.05). The overall caesarean section rate for a fetus in breech presentation was 50%. There were no serious complications associated with version and the condition of the infants at birth was better in the version group than in the control group. We advise external version under tocolysis in late pregnancy to reduce the frequency of breech presentation in labour.