Height of elevated fetal buttock for prediction of successful external cephalic version

Abstract

ObjectiveTo increase the rate of successful external cephalic version (ECV) and to minimize the complications, it is important toidentify the predictors of success. Therefore, the purpose of this study was to investigate whether the height of theelevated fetal buttock (HOB) is a valuable predictor of successful ECV or not. MethodsThis prospective study was conducted from August 2016 to June 2018. A total of 139 pregnant women with breechpresentation were enrolled in the study. HOB from the maternal pubic symphysis was measured on ultrasonography. The predictability and cut-off value of HOB for successful ECV were evaluated. ResultsAmong the 139 patients, 114 (82%) had successful ECV. The adjusted odds ratio for multiparity, amniotic fluid index(AFI) >14 cm, and HOB >7.8 cm were 10.80 (95% confidence interval [CI], 1.57–74.94), 5.26 (95% CI, 1.06–26.19), and10.50 (95% CI, 1.03–107.12), respectively. Areas under the curve (AUCs) for AFI, HOB, and parity were 0.66 (95% CI,0.54–0.78), 0.74 (95% CI, 0.64–0.85), and 0.69 (95% CI, 0.62–0.76), respectively. HOB had the largest AUC, but therewere no significant differences among the AUCs of other factors. The cut-off value of HOB was 6 cm. ConclusionThis study showed that the AUC of HOB was greater than that of parity and AFI, although it was not statisticallysignificant. As HOB is a noninvasive and comprehensive marker to predict successful ECV, consideration of HOB wouldbe helpful before conducting ECV. Further studies are needed.