Developing a nomogram for estimating the risk of needing to perform a caesarean section after induction of labour in pregnancies using a COOK® Cervical Ripening Balloon

Abstract

BACKGROUND: Using a COOK® Cervical Ripening Balloon (CCRB) for cervical maturity has become a common clinical practice for the induction of labour (IOL). OBJECTIVE: To develop and validate a predictive instrument that could estimate the risk of a caesarean after IOL in term pregnancies with CCRB treatment. METHODS: The medical records of 415 pregnant women requiring IOL from January 2018 to October 2022 were retrospectively reviewed and randomly selected for training (290) and validation (125) sets in a 7:3 ratio. A model for predicting the risk of a caesarean was virtualised by a nomogram using logistic regression analysis. RESULTS: After completing the multivariate analysis, parity (odds ratio [OR] = 0.226; p= 0.017), modified Bishop score at induction (OR =0.688; p= 0.005) and the artificial rupture of membranes (OR = 0.436; p= 0.010) were identified as the predictors for implementing a caesarean delivery after IOL. The decision curve analysis showed that the model achieved a net benefit across all threshold probabilities. CONCLUSION: We successfully constructed a nomogram for caesarean delivery after IOL in pregnancies with CCRB treatment using factors including parity, modified Bishop score at induction and the artificial rupture of membrane.