Atosiban vs. ritodrine as a tocolytic in external cephalic version at term: a prospective cohort study.

ABSTRACT

OBJECTIVE: To compare the success rate of external cephalic version (ECV) at term using ritodrine or atosiban as a tocolytic agent. STUDY DESIGN: Prospective cohort study with a sample of 236 pregnant women with a breech presentation at term, from November 2006 to March 2008. Data have been analyzed from the moment the cephalic version is performed until the time of delivery. RESULTS: ECV success rate using ritodrine as a tocolytic agent was 56.8% compared to 31.4% with atosiban. Ritodrine increases the version success potential more significantly than atosiban (P<0.05). In both cases, the use of ECV reduced the rate of cesarean sections, although a higher number of versions are required with atosiban [numbers needed to treat (NNT)=9.08] to avoid a cesarean section compared to ritodrine (NNT=3.41). CONCLUSIONS: Ritodrine seems better than atosiban as tocolytic agent for ECVs.