Poster Session
Objectives: To analyse the contribution of individual components of Bishop Score in predicting vaginal delivery, to develop a simplified score from the components that independently predicts vaginal delivery and to compare the efficacy of the simplified score with that of original Bishop Score. Study design: Prospective cohort study Population: Thousand pregnant women with a singleton gestation of more than 37 weeks and less than 42 weeks with cephalic presentation and intact membranes undergoing induction of labour were recruited to the study. Exclusion criteria were women with previous scar, intrauterine death, malformed fetus, prelabour rupture of membranes, intrauterine growth restriction, chorioamnionitis and antepartum haemorrhage. Methods: All women participating in this study were subjected to digital examination, just before induction and a Bishop score was recorded giving score for all its five components. Participants were followed up till delivery. Obstetric and neonatal data were noted. Logistic regression with enter method was performed to analyse the contribution of each component of pre-induction Bishop score in predicting vaginal delivery and achievement of active phase of labour. Results: No significant difference in the mean age, BMI, parity, pre-ripening Bishop score, pre-induction Bishop score were noted in the groups undergoing vaginal delivery(n=874) and caeserean section(n=126). Cross-tabulation between parity, pre-induction Bishop score and mode of delivery showed 94% of successful inductions in both the nullipara and multipara group irrespective of the Bishop score category. Extended ripening strategy used in the protocol had resulted in a very few women having consistency other than soft and position other than central and hence lack of variation in these factors among the women studied. On binary logistic regression using multivariate analysis, no single component of pre-induction Bishop score had a significant p value in predicting vaginal delivery or achievement of active phase of labour. Conclusion: In the setting of optimal pre-induction cervical ripening, no single component of Bishop score was found to be predictive of achieving active phase of labour or vaginal delivery following induction of labour at term.