Research implications
Although we have developed a prediction model and validated the model in an independent study population, the developed model should be further evaluated in other institutions with different races/ethnicities to confirm the results of this current study. Moreover, through a prospective randomized trial, we may be able to establish new protocols regarding the usefulness of the developed prediction model. In addition, the maternal or neonatal outcomes in terms of morbidity/mortality after IOL in twin pregnancies need to be evaluated.