Accuracy of preinduction transvaginal sonography (TVS) and bishop scores in predicting successful labor induction: a global systematic review and meta-analysis.

OBJECTIVE

Labor induction is a common obstetric procedure, with success depending on accurate cervical assessment. The Bishop score, used traditionally, is subjective and limited, while transvaginal sonography (TVS) offers objective cervical length measurement. This systematic review and meta-analysis aimed to compare the accuracy of preinduction TVS and Bishop Score in predicting successful labor induction.

METHODS

Following PRISMA guidelines, we searched PubMed, Scopus, Web of Science, and Lens.org for articles from January 2015 to October 2024 for observational studies comparing TVS and Bishop Score in term pregnancies (≥37 weeks). Eligible studies reported diagnostic accuracy metrics for successful vaginal delivery. Data were extracted using a standardized form, and study quality was assessed with QUADAS-2. A random-effects meta-analysis calculated pooled log odds ratios (ORs), with heterogeneity assessed via I2 and publication bias via fail-safe N, Kendall's tau, and Egger's regression. A p-value <0.05 was considered significant.

RESULTS

Ten studies (n = 1,612 patients) were included from diverse regions (India, Iran, Türkiye). The pooled OR was 2.1726 (95% CI: 0.9493-4.9706, p = 0.0662), suggesting TVS has 2.17 times higher odds of predicting successful induction than Bishop score, though not statistically significant. TVS achieved a 60.2% success rate versus 48.7% for Bishop score (absolute difference: 11.5%). High heterogeneity (I2 = 73.12%, p < 0.001) was observed, with TVS performing better in primigravida and prostaglandin induction settings. No publication bias was detected (Fail-Safe N = 35, Egger's p = 0.944).

CONCLUSION

TVS shows a moderate, non-significant advantage over Bishop score in predicting successful labor induction. High heterogeneity suggests context-specific performance. Further research should explore whether a combined TVS-Bishop score approach could optimize clinical decision-making. Further research is needed to standardize protocols and assess cost-effectiveness across diverse settings.