Prediction of successful induction of labor: comparison of transvaginal ultrasonography and the Bishop score.
OBJECTIVE
To determine whether transvaginal ultrasonography of the cervix before induction of labor is a better predictor of successful induction than the Bishop score.


METHODS
Eighty-six consecutive patients scheduled for induction of labor underwent digital cervical examination followed by transvaginal ultrasonography to measure cervical length and to determine the presence of wedging. Patients were induced with either oxytocin or intracervical prostaglandin E2 gel followed by oxytocin when required. The agent for induction was selected on the basis of the digital examination. The primary outcome criteria were successful induction and the duration of labor.


RESULTS
Successful induction and the duration of labor were significantly associated with the Bishop score and cervical length. Cervical wedging was associated only with successful induction. However, in a logistic regression model that included these parameters as independent variables, only the Bishop score and parity were significantly correlated with successful induction and the duration of labor.


CONCLUSIONS
Transvaginal ultrasonographic evaluation of the cervix before induction of labor does not improve the prediction of cervical inducibility obtained by the Bishop score.
Division of Maternal-Fetal-Medicine and the Ultrasound Unit, Department of Obstetrics and Gynecology, Bnai Zion Medical Center, Faculty of Medicine, Technion, Haifa, Israel.
R
R
Gonen
S
S
Degani
A
A
Ron
D000328:Adult; D020070:Cervical Ripening; D002584:Cervix Uteri / Q000000981:diagnostic imaging; D015232:Dinoprostone; D005260:Female; D006801:Humans; D007751:Labor, Induced; D010120:Oxytocics; D010121:Oxytocin; D011237:Predictive Value of Tests; D011247:Pregnancy; D016216:Ultrasonography, Prenatal
D010120:Oxytocics; D010121:Oxytocin; D015232:Dinoprostone