Clinical implications
For clinical utility, a nomogram for the prediction of cesarean delivery after induction was constructed according to the final prediction model (Figure 1). In addition, a web-based calculator was created to estimate the likelihood of cesarean delivery after IOL in twin pregnancies (Figure 2, http://snuhtwin.com/). The nomogram and calculator will be useful when considering counseling for labor induction in twin pregnant women without contraindications for vaginal delivery. In particular, this predictive calculator can be used to provide clinical information for twin pregnant women who are considering IOL.