[The Bishop score and induction of labor]

Induction of labor represents initiation of uterine contractions before their spontaneous onset. The aim of the study was to establish the role of Bishop score in prediction of labor induction in routine clinical work.

The study was a prospective, blind, observational one. All patients had a vaginal examination prior to induction, during which Bishop score was evaluated. The mode of induction was either intravenous infusion of oxytocin or endovaginal prostaglandins. The induction was considered successful if vaginal delivery took place within 24 hours from the onset of induction.

There were 100 patients, and induction was successful in 74% and unsuccessful in 26%. Mean Bishop score in group A was 5.65 (SD 1.40, 95% CI 5.27-6.03), and in group B 4.15 (SD 1.04, 95% CI 3.66-4.63) (p < 0.01). Statistical analysis of the area under the ROC curve showed that Bishop score is a good and reliable predictor of the outcome of labor induction (0.816, 95% CI od 0.710-0.896), with the best statistical performances at the cut-off value of 5 (sensitivity 65.5%, specificity 95%, PPV 97.3%, NPV 50%).

In our study Bishop score proved to be a reliable and good method for prediction of the outcome of pregnancy if a single, experienced operator evaluates it, with best statistical performances at the cut-off value more than 5 (sensitivity 65.5%, specificity 95%, PPV 97.3%, NPV 50%). The next step would be introduction of more operators, of different skills and experience and subsequent further testing of the method in different conditions.