Bishop score and cervical length at 33-35 weeks of gestation and the risk of intrapartum cesarean delivery of twins

Aim: The aim of this study is to determine the association between Bishop score and cervical length measured at 33-35 weeks of gestation and the intrapartum risk of cesarean delivery of twins. Methods: This prospective observational study recruited women with vertex/vertex twin gestations at 33-35 weeks of gestation. Determination of the Bishop score and ultrasound measurement of the cervical length were performed. A regression model was constructed with control for known intrapartum and postpartum confounders. Results: One hundred and forty-six women were analyzed; 18 women (12.3%) had cesarean deliveries during labor. Based on univariate nalysis, the Bishop score at 33-35 weeks was significantly associated with the risk of intrapartum cesarean delivery of twins, whereas cervical length, maternal age, height, and weight at 33-35 weeks were not associated. Multivariate logistic regression analysis identified induction of labor and birth weight of the first-born twin, but not Bishop score, as independent predictors of intrapartum cesarean delivery of twins. Conclusions: A low Bishop score at 33-35 weeks of gestation was associated with an increased risk of intrapartum cesarean delivery of twin gestations. However, this relationship disappeared after adjusting for relevant intrapartum or postpartum confounders. Only labor induction and high birth weight of the first-born twin were independently associated with an increased risk of cesarean delivery in labor.