THE VALUE OF THE CERVICAL SCORE IN PREDICTING SUCCESSFUL OUTCOME OF LABOR INDUCTION

Objective: To compare cervical dilation and the Bishop score as correl ates of successful labor induction and vaginal delivery and to determi ne whether the prognosis of post-ripening cervical characteristics var ies with the method of ripening used. Methods: Four hundred forty-thre e women with Bishop scores less than 9 who required induction of labor were assigned randomly to cervical ripening with prostaglandin E-2 ge l or hygroscopic dilation. The Bishop score and its component characte ristics were evaluated as univariate correlates of successful inductio n of labor and vaginal delivery and then were assessed using logistic regression to adjust for other maternal and fetal factors. The differe nces in the association between method of ripening and successful labo r induction were evaluated relative to pre-ripening and post-ripening cervical examination characteristics. Results: Cervical dilation was a better correlate of successful labor induction and vaginal delivery t han was the Bishop score, even after exclusion of patients with initia l Bishop scores greater than 6 and dilation greater than 3.0. Both rip ening methods yielded similar success in labor induction and vaginal d elivery, but when categorized by post-ripening cervical examinations, patients undergoing hygroscopic ripening had lower rates of successful labor induction and vaginal delivery. Conclusion: Cervical dilation i s a better predictor of successful labor induction and vaginal deliver y than either the Bishop score or any other Bishop score component cha racteristic. The likelihood of successful labor induction and vaginal delivery based on post-ripening cervical characteristics varies by the ripening method used. (C) 1997 by The American College of Obstetricia ns and Gynecologists.