Prediction of successful vaginal delivery in women undergoing external cephalic version at term for breech presentation.
OBJECTIVE
The aim of this study is to evaluate the clinical and sonographic predictors of ultimate successful vaginal delivery in women undergoing external cephalic version.


METHODS
The study population consisted of women with external cephalic version performed at or after 36 weeks of gestation. They were randomized into group A or B, each consisted of half of the total study population. Logistic regression was performed on group A to identify the significant independent variables in predicting successful cephalic vaginal delivery, which were used to construct a prediction model. The derived regression model was then tested in group B to assess its accuracy.


RESULTS
The study included 407 pregnancies. Maternal weight (kg) at the time of version, maternal height (cm), multiparity, engagement of fetal presenting part, and fetal head palpable were significant independent variables of successful version and vaginal delivery (regression coefficients are: -0.084, 0.085, 1.752, -1.271, and 0.725, respectively). A prediction model was constructed based on these independent variables. The weighted average of the overall accuracy in predicting success or failure of version and vaginal delivery was 70.9%. The regression model was then applied to study group B. Using 0.50 as the cutoff value, the sensitivity, specificity, positive, and negative predictive values were 75.4, 58.8, 73.7, and 61.0%, respectively.


CONCLUSIONS
A regression model constructed based on clinical variables failed to provide an accurate predictive tool of successful external cephalic version and vaginal delivery. However, in women who are equivocal about external cephalic version, a high prediction of success would be encouraging.
Department of Obstetrics and Gynecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Block E, 1/F Shatin, Hong Kong. lyschan@cuhk.edu.hk
Louis Yik-Si
LY
Chan
Tak Yeung
TY
Leung
Wing Yee
WY
Fok
Lin Wai
LW
Chan
Tze Kin
TK
Lau
D000328:Adult; D001946:Breech Presentation; D036861:Delivery, Obstetric / Q000379:methods; D005260:Female; D006801:Humans; D015233:Models, Statistical; D011237:Predictive Value of Tests; D011247:Pregnancy; D016216:Ultrasonography, Prenatal; D014710:Version, Fetal