Comparison of Bishop’s score with transvaginal sonographic cervical assessment to predict success of induction of labor

Abstract

Induction of labor for medical or obstetric indications is a common practice in modern obstetrics. Evaluation of the cervix by Bishop’s score is universally used to predict the success of induction of labor. But it is a subjective method and many studies have shown that it is not a good indicator of success of induction. To compare Bishop’s scoring system and trans-vaginal sonographic assessment of cervix in predicting the successful outcome of induction of labor.This was an observational study conducted in a tertiary care center. 120 patients who met the selection criteria were included. Prior to the induction of labor the Bishop’s score and the sonographic scoring was assigned. Successful induction was defined as the patient entering the active phase of labor. 84% of participating women entered the active phase of labor. While 72.6% women had a normal vaginal delivery, 67.8% women delivered vaginally within 24 hours of induction. The TVS score (MGPICSS) of ≥2 predicted the successful induction with a specificity of 100% and sensitivity of 39.3% and AUC 0.74. In comparison, the Bishop score of ≥4 had a specificity of 75% and sensitivity of 44% and AUC 0.56. The prediction of delivery within 24 hours at the MGPICSS of ≥2 had a specificity of 100% and sensitivity of 42.9% and AUC 0.76. For the same, the Bishop’s score of ≥4 had specificity of 83.3% and sensitivity of 45.5% and AUC 0.71. TVS assessment of cervix is a better predictor of successful labor induction in comparison to Bishop’s score.