Posterior cervical angle and cervical length in predicting the successful induction of labour in nulliparous woman

Objective:To assess the value of pre-induction sonographic assessment of the posterior cervical angle (PCA) and cervical length in the prediction of successful induction of labor (IOL).Patients and Methods:The present prospective observational study included IOL candidates who had their PCA and cervical length assessed by transvaginal ultrasonography and the Bishop score at the Obstetrics and Gynecology Department, Ain-Shams Maternity Hospital, Cairo, Egypt, from 1st November 2018 to 31st May 2019. The accuracy of these tests in predicting successful IOL (defined as vaginal delivery) was compared.Results: The analysis included 41 women with successful IOL and 29 women with unsuccessful IOL. The suggested cutoffs for the prediction of successful IOL were a PCA of more than 100°, a cervical length of less than 31 mm, and a Bishop score of more than four. The areas under the receiver operating characteristics curves for these three measures were not significantly different. However, a PCA of more than 100° had the best sensitivity (87.80%), specificity (86.21), positive predictive value (90%), negative predictive value (83.3%) compared with the other two predictors.Conclusion: Posterior cervical angle had the best accuracy in predicting successful induction of labor compared with the cervical length and the Bishop score