Cervical Ultrasound Assessment vs Bishop Score in Predicting Labor Induction Outcomes Among Nulliparous Women

Objective: Induction of labor (IOL) failure increases the risk of maternal and neonatal complications. The traditional Bishop score (BS) for cervical assessment is limited by subjectivity and inter - observer variability. This study aimed to evaluate cervical status via ultrasound examination (UE) as an alternative to vaginal examination (VE), and compare its predictive performance for IOL outcomes with the BS. Methods: In this prospective observational study, 106 nulliparous women with singleton pregnancy requiring IOL were enrolled from January 2024 to August 2025. Of these participants, 83 had successful IOL and 75 achieved vaginal delivery (VD). Cervical length (CL), posterior cervical angle (PCA), angle of progression (AoP), and cervical shear wave elastography (SWE) were measured, and compared with the conventional BS. The primary outcomes were successful IOL and VD. Multivariate logistic analysis was performed to identify independent influencing factors for the two outcomes, and ROC curve analysis was used to evaluate their predictive efficacy. Results: Significant differences were observed in ultrasound parameters between groups stratified by both outcomes ( P < 0.05), whereas BS indicators showed no significant differences (all P > 0.05). Multivariate logistic analysis showed that only cervical SWE was independently correlated with successful IOL and VD ( P < 0.05), with superior predictive power compared with BS (AUC of 0.78 vs 0.53 for successful IOL and 0.78 vs 0.56 for VD). Significant differences in pain perception existed between VE and UE (χ 2 = 212.00, P < 0.001). All participants suffered moderate to severe pain after VE, while nearly 85% felt pain - free and none had moderate or severe pain after UE. Conclusion: Ultrasound outperformed BS in evaluating cervical morphology owing to its objectivity, repeatability, and visualization capability in routine practice, and also yielded a better patient experience before IOL. Cervical stiffness appears to be an important influencing factor for IOL success, and SWE shows potential as a promising predictive approach for IOL outcome.