Bishop score and transvaginal ultrasound for preinduction cervical assessment: a randomized clinical trial

Background: The objective was to compare transvaginal ultrasound with the Bishop score for preinduction cervical assessment and for choice of induction agent. Methods: 150 women were randomized to have preinduction cervical assessment for choice of induction agent based on either Bishop score or transvaginal ultrasound. The primary outcome measure was the percentage of women who were administered prostaglandin as a preinduction agent. The criteria for considering the cervix as unripe and thus for using prostaglandin were either a Bishop score