Adding parity to the Bishop score for term labor induction: A retrospective study

Objective. - To evaluate the interest to add parity to the Bishop score before induction of labor by intravenous oxytocin. Patients and methods. - This retrospective cohort study compared cesarean section rate for induction failure by intravenous oxytocin in nulliparous and multiparous with modified Bishop score from 7 to 9. The modified Bishop score is calculated by adding 2 points to the Bishop score if the patient had a previous vaginal delivery and 0 point in nulliparous. Results. - Over 2 years, 468 patients were included (201 nulliparous and 267 multiparous). Cesarean section rate for induction failure was higher for nulliparous with a modified Bishop score equal to 7 or varying between 7 and 9. These results confirm that parity is an important predicting factor of successful labor induction. In multiparous, cesarean section rates for induction failure were not significantly different with Bishop score or modified Bishop score equal to 7. Conclusion. - Adding 2 points for multiparity at the Bishop score did not increase cesarean for failure of labor induction with intravenous oxytocin with a modified Bishop score from 7 to 9. (C) 2012 Elsevier Masson SAS. All rights reserved.