The role of bladder volume in the success of external cephalic version

Abstract

ObjectiveNumerous studies have evaluated the factors associated with ECV success. Yet, bladder volume has never been examined. We hypothesize that maternal bladder volume may affect ECV success rate. We aim to evaluate the role of maternal bladder volume during external cephalic version (ECV) on the procedure success rates. Study designWe reviewed prospective collected data of all patients who underwent ECV at our center during 2001–2012. The study group included 100 patients that underwent ECV with bladder volume below 400 ml. These patients were matched to 400 patients that underwent ECV with bladder volume equal or above 400 ml which composed the control group. Maternal and fetal characteristics and outcomes were compared. ResultsECV was successfully performed in 80/100 (80.0%) of patients in the study group as compared to 257/400 (64.3%) in the control group (P = 0.002). Factors associated with ECV success were older age (P = 0.003), having prior delivery (P < 0.0001), higher amniotic fluid index (AFI) (P = 0.001) and placenta located in the posterior wall (P = 0.001).In a logistic regression analysis, bladder volume was found to be an independent predictor of ECV success Odds radio (OR) for ECV success 2.5 (CI 1.42–4.34). Posterior placenta and higher AFI were found to be an independent predictors of ECV success as well; OR 2.7 (CI 1.74–4.34) and OR 1.07 (CI 1.02–1.13) respectively. ConclusionECV is more successful in patient with bladder volume below 400 ml. Amniotic fluid volume and placental location were found as independent predictors of ECV outcome as well.