Ultrasound factors to predict the outcome of external cephalic version: a meta-analysis

Objective To systematically review the medical literature reporting on ultrasound factors that can be predictive for the outcome of an attempt at external cephalic version (ECV). Methods MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials were searched. Studies reporting on potential ultrasound prognosticators and ECV success rates that allowed construction of a 2 x 2 table were selected. Results We selected 37 primary articles reporting on 7709 women. Posterior placental location (odds ratio (OR), 1.9; 95% CI, 1.5-2.4), complete breech position (OR, 2.3; 95% CI, 1.9-2.8) and an amniotic fluid index > 10 (OR, 1.8; 95% CI, 1.5-2.1) were predictors of successful ECV. Conclusion Success of an ECV attempt is associated with ultrasound parameters such as fetal position, amniotic fluid and placental location. This knowledge can be used to develop a prognostic model to predict successful ECV. Copyright (C) 2008 ISUOG. Published by John Wiley & Sons, Ltd.