Comparison of Ultrasonographic Cervical Length and the Bishop Score in Predicting Successful Labor Induction in Nulliparous Women

Abstract

SUMMARY ne aim of the study had been to test an alternative means for cervical favorability akin to the Bishop score by using transvaginal ultrasound measurements. In the current study cervical length correlated significantly with the outcome of induction. This measurement may reflect overall favorability, being uninfluenced by cervical position, application, effacement and consistency. Patients preferred transvaginal ultrasound to digital assessment but the results of this study suggest that the best overall prediction is achieved by combining the two methods. If cervical length measurements are confirmed by further studies as being as accurate as, or more accurate than Bishop score in predicting outcome of induction, transvaginal ultrasound could be considered in combination with digital examination in the assessment of cervical favourability before induction of labor. This prospective study was conducted at Ain Shams University Maternity Hospital. 210 primigravid women undergoing induction of labour for various indications were recruited in the current study. The main indication for induction of labour was postdate pregnancy (58.1%) followed by prelabor rupture of membranes (PROM) (28.57%). Patients recruited had a mean age of 24.13 (18-35) years and a median gestation of 38 (37-41) weeks. Prior to induction O Summary 136 of labor patients underwent cervical assessment with transvaginal sonography followed by digital cervical assessment using Bishop Score. Statistical analysis revealed that cervical length measured by transvaginal sonography was more sensitive and specific than the Bishop score for the prediction of successful labor induction. Cost and availability may limit the application of transvaginal ultrasound for this purpose, but the technique is easy to learn and yields objective rather than subjective measurements of the cervix