Abstract :
Background: Induction of labor (IOL) is a critical intervention aimed at facilitating childbirth for various reasons. When it fails, there is an increased likelihood of delivery by cesarean section. Any tool that can accurately predict the success of IOL can improve maternal and fetal outcomes. This can be achieved by incorporating transvaginal sonographic parameters namely posterior cervical angle (PCA) and cervical length to predict the mode of delivery along with Bishop score.Materials and Methods: This prospective observational study included 115 participants at term with singleton gestation. The subjects underwent pre-induction cervical assessment using Bishop score and measurement of posterior cervical angle and cervical length using transvaginal sonography. The study compared the sonographic parameters with Bishop's score among the participants to accurately predict the mode of delivery.Results: IOL was successful in 74% of cases (N=85) and unsuccessful in 26% of cases (N=30). PCA >99 degrees, cervical length of less than or equal to 2.6cm, and Bishop score of >3 could successfully predict vaginal delivery. However, a PCA of >99 degrees had the best sensitivity, positive predictive value, negative predictive value, diagnostic accuracy and was superior to cervical length and Bishop score in predicting the success of labor induction.Conclusion: Both PCA and cervical length are complementary tools for accurate cervical assessment prior to IOL. However, PCA is the most important determinant in predicting the chances of success of labor induction thereby helping the obstetrician and patient in prompt decision making.
Keyword :
Posterior cervical angle, Cervical length, Labor induction, Bishop score, Transvaginal sonography.