High incidence of obstetric interventions after successful external cephalic version.

Objective: To investigate the delivery outcome after successful external cephalic version (ECV).

Design: Case-control study.

Setting: University teaching hospital.

Population: The study group consisted of 279 consecutive singleton deliveries at term over a six-year period, all of which had had successful ECV performed. The control group included 28,447 singleton term deliveries during the same six-year period.

Methods: Between group differences were compared with the Mann-Whitney U test or Student's t test where appropriate. Odds ratio and 95% confidence interval (CI) were calculated for categorical variables. Main outcome measures Incidence of and indications for obstetric interventions.

Results: The risk of instrumental delivery and emergency caesarean section was higher in the ECV group (14.3% vs 12.8%; OR 1.4; 95% CI 1.0-2.0, and 23.3% vs 9.4%; OR 3.1; 95% CI 2.3-4.1, respectively). The higher caesarean rate was due to an increase in all major indications, namely, suspected fetal distress, failure to progress in labour and failed induction. The higher incidence of instrumental delivery was mainly due to an increase in prolonged second stage. The odds ratio for operative delivery remained significant after controlling for potential confounding variables. There were also significantly greater frequencies of labour induction (24.0% vs 13.4%; OR 2.0; 95% CI 1.5-2.7) and use of epidural analgesia (20.4% vs 12.4%; OR 1.8; 95% CI 1.4-2.4) by women in the ECV group. The higher induction rate is mainly due to induction for post term, abnormal cardiotocography (CTG) and antepartum haemorrhage (APH) of unknown origin.

Conclusion: The incidence of operative delivery and other obstetric interventions are higher in pregnancies after successful ECV. Women undergoing ECV should be informed about this higher risk of interventions.