External cephalic version: Predictors for success

The objective of this study was to identify the factors predictive of the success of external cephalic version (ECV).

A single-centre retrospective observational study was performed in the maternity ward of the Angers University Hospital, France, between January 2010 and May 2020. The study included all patients (n = 613) for whom an ECV was performed for a breech or transverse foetus. The primary endpoint was measured by the success of the ECV, defined by the visualisation, using pelvic ultrasound, of the foetus in cephalic presentation immediately after the manoeuvre. Following to the ECV, the cohort was separated into two groups; ECV Success and ECV Failure. In order to determine the predictive factors of success, a logistic regression model was performed, including the parameters of: parity, foetal presentation during ECV, the side of the foetal back, placental location, type of operator and maternal age. The results are presented as (odds ratio [confidence intervals]; p-value). The significance threshold was defined by a p-value < 0.05.

The ECV success rate was 21.4% (131/613). The factors predictive of the success of ECV were: transverse foetal presentation (2.7 [1.3-5.6]; p<0.01); a senior physician operator (1.6 [1.2-2]; p<0.01); multiparity (1.6 [1.2-2]; p<0.01); non anterior placental localization (1.4 [1.1-2]; p<0.01). A number of attempts greater than 3 were significantly associated with reduced chances of success (0.3 [0.2-0.4]; p<0.01).

The study shows that transverse foetal presentation, a senior physician operator, multiparity, as well as a non-anterior placental location are factors predictive of the success of ECV. Knowledge of these factors can improve the information given to patients.