Main findings
The principal findings of this study were: (1) We developed a prediction model, composed of five variables (maternal age, maternal height, parity, cervical effacement, and total birth weight of twins), for cesarean delivery after IOL in twin pregnant women; (2) In addition, a nomogram for predicting the risk of cesarean delivery after IOL in twin pregnancies was developed; and (3) The developed prediction model showed good performance in both the development and external validation databases.
To predict the risk of cesarean delivery after IOL in twin pregnancies, we compared many clinical variables including maternal age, maternal height, maternal weight, pregestational BMI, parity, gestational age at IOL, gestational age at delivery, method of conception, cervical examination, chorionicity, presentation and birth weight of each twin, and total birth weight of twins. We found some independent risk factors that increased the risk of cesarean delivery, and the final prediction model included maternal age, parity, maternal height, cervical effacement, and total birth weight of twins. Maternal age, maternal height, and cervical effacement are also known risk factors in singleton pregnancies.25,26 The birth weight-related variable retained in the final model was the total birth weight of twins.
To our knowledge, this is the first study to develop a prediction model for cesarean delivery after IOL in twin pregnancies. Several studies have reported many prediction models after IOL in singleton pregnancies.25,27 The AUROC of the prediction model in the current study was 0.742 (95% CI 0.700-0.785) in the training set, 0.733 (95% CI 0.671-0.794) in the test set, and 0.714 (95% CI 0.650-0.777) in the validation cohort, which is similar to the reported AUROC of the prediction models in singleton pregnancies (AUROC 0.787 [95% CI 0.786-0.788] in the study by Rossi et al.27, 0.79 [95% CI, 0.74-0.83] in the study by Levine et al.25).