Sonographically accessed funneling of the uterine cervix as a predictor of successful labor induction

OBJECTIVE The Bishop score and length of the uterine cervix are good predictors of successful labor induction. However, little is known about the association between the funneling of the uterine cervix and successful labor induction. The study aimed to evaluate cervical funneling as a predictor of successful labor induction. METHODS This study was designed as a prospective observational study. Subjects who delivered a baby by labor induction were enrolled in the study from July 2011 to August 2013. Cervical funneling and length were examined with transvaginal ultrasonography. The Bishop score was rated by digital pelvic examination. RESULTS A total of 163 primigravida women were recruited for the study. Of these, 137 participants (84.0%) delivered vaginally by labor induction. Cervical funneling was observed in 93 women (57.1%). Successful labor induction was significantly higher in patients with cervical funneling than those without it (91.4% vs. 74.3%, P<0.01), and was significantly associated with cervical funneling, as well as the Bishop score and cervical length. In a multivariate analysis, cervical funneling was an independent predictor for successful vaginal delivery by labor induction ( odd ratio, 2.70; 95% confidence interval, 1.02 to 7.10; P=0.04). However, the Bishop score and cervical length had no association with successful vaginal delivery. CONCLUSION This study showed that cervical funneling could be a predictive marker for vaginal delivery during labor induction.