Oral Concurrent 2 Thursday, February 14 • 1:15 PM - 4:00 PM • Augustus Ballroom 3-4 • Caesars Palace| Volume 220, ISSUE 1, SUPPLEMENT , S22-S23, January 01, 2019

27: Externally validated induction score from a prospective population-based cohort study in 94 maternity units


      No induction score has emerged as a standard to substitute the Bishop score, especially in case of cervical ripening. The objective of our study was to build a score to predict the risk of cesarean section, from a population-based dataset especially designed for induction analysis purpose.

      Study Design

      We used the dataset from the prospective multicenter observational French population-based cohort study MEDIP (Methods of Induction of Labor and Perinatal outcomes), which had for objective to collect national data about labor induction practices. For the present study, we excluded all patients with twin pregnancies, non-cephalic presentations, previous c-section, premature deliveries, and cases of induction without cervical ripening. A total of 1 692 patients were analyzed and randomly split in a derivation dataset of 1 024 patients (60%) and an internal validation set of 668 patients (40%).
      Statistical analyses were performed by using a Bayesian approach. Variables with a probability of being associated with cesarean delivery (Prob OR > 1) greater than 0.90 (i.e. indicating an increased risk of cesarean delivery) were entered in the multivariate model, and then maintained in the final model depending on the Deviance Information Criterion. When available, results from previous studies from literature were used to build informative prior distributions on the log(OR).
      The score was validated using the internal validation set, and an external dataset from the Consortium for Safe Labor database (NIH database that includes labor and delivery information collected from 19 hospitals across the US from 2002 through 2008). The validation of the model was assessed using AUC and a graphical representation of the calibration.


      The multivariate model for prediction of c- section in case of induction after cervical ripening is reported in Table 1. The 50 points induction score is displayed in Figure 1. On the external validation set, the AUC for the present score, the Levine score (Levine et al., AJOG 2017), and the modified Bishop score are respectively 0.81 [0.79-0.82], 0.76 [0.75-0.78] and 0.71 [0.70-0.73].


      We developed an easy-to-use, externally validated and efficient score to predict c-section after labor induction with cervical ripening.
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