Can We Use the Bishop Score as a Prediction Tool for the Mode of Delivery in Primiparous Women at Term Before the Onset of Labor?

Unlabelled: The Bishop score serves as an evaluation system performed by digital vaginal examination (DVE) to determine cervical ripening. The scoring system includes cervical dilatation, position, effacement and consistency of the cervix and fetal head station1. Nowadays, the Bishop score is frequently used as an important parameter for the prediction of successful induction of labor.

Objective: Our objective was to demonstrate the role of the Bishop scoring system in prediction of the mode of delivery in primiparous women at term before the onset of labor.

Method: We included in this study unselected primiparous women at term, after 37 weeks of gestation, who presented to the Prenatal Diagnostic Unit (PDU) of the University Emergency County Hospital of Craiova. We excluded from the study multiparous patients, pregnancies with a planned Caesarean section delivery (CD), non-cephalic presentations and multiple pregnancies, twin pregnancies and those with detected fetal anomalies. The protocol included weekly DVEs until delivery for all patients, to determine the evolution of the Bishop score at term and in the week before delivery, and potential correlations with delivery outcome. To reduce clinical bias, the DVEs were performed by three experienced obstetricians involved in the research.

Results: Statistical analysis yielded a 4 to 6 Bishop score in all weekly examinations. At 37 weeks of gestation, the majority of primiparous women had a Bishop score of 4, with no significant differences between the primiparous who delivered vaginally and the ones where Caesarean section was necessary. During the following weekly evaluations, we noted a slight turn to a Bishop score of 6 for most of them, without any significant differences between the two groups. However, at 41 weeks of gestation, there was a significant higher Bishop score in the group of primiparous women who delivered vaginally.

Conclusion: In our study, the use of the Bishop score failed as a prediction tool for the mode of delivery in primiparous women at term before the onset of labor, at a gestational age less than 40 weeks. Therefore, Bishop score should not be used to counsel regarding the probability of an uncomplicated vaginal delivery (VD) before the onset of labor.