Comparative study Of TVS cervical score and Bishop score in prediction of successful labour induction

Abstract

BackgroundIn today's obstetric practice, induction of labour is a common procedure. Before the imaging era, the favourability of the cervix was assessed by manual examination scored as the Bishop Score. However, subjectivity and high inter- and intra-observer variability are limitations of this approach. This necessitates the implementation of an objective method of assessment. We used transvaginal sonography (TVS) as an objective method of assessment of cervix by TVS cervical score comprising of five different parameters; cervical length, funnelling at the internal os, distance from the presenting part to the external os, and cervix position. This study aims to evaluate the role of the pre-induction transvaginal ultrasonographic (TVS) cervical score in predicting labour outcome and comparing it to the Bishop score in patients undergoing induction of labour.MethodologyThis observational prospective study included 100 pregnant women admitted for labour induction at a single tertiary care centre. The TVS examination which consisted of five parameters was performed after the clinical Bishop scoring. The TVS scores were compared with the Bishop scores for all patients. Labour induction was done within one hour of examination and the outcome of the induction was recorded.ResultsThe mean age was 25.87 years [SD = 4.35]. Labour induction was successful in 74% of patients. At cut-off Scores of ≥ 4, TVS cervical Score performed better than Bishop Score (Sensitivity 93.24 vs. 67.57%, Specificity 73.08 vs. 65.38%). ROC analysis indicated that Area Under Curve (AUC) was more for TVS Score (0.91, 95% CI 0.84–0.97), compared to Bishop Score.ConclusionTransvaginal ultrasonography is an objective method of cervical assessment. We conclude from our study that the use of TVS score which consists of five different parameters in cervical assessment provides a better prediction of successful labour induction than the Bishop score, and so can prevent various complications associated with induction failure.