Introduction
Recent improvement in assisted reproductive technologies (ART) has led to an increase in the rate of twin pregnancies.1,2 Compared to singleton pregnancies, twin pregnancies are at a higher risk for gestational hypertension, preeclampsia,3,4 intrahepatic cholestasis,5 and gestational diabetes.6 Moreover, there is a higher risk of stillbirth with advancing gestational age even in uncomplicated twins,3-8, and elective delivery at 37-38 weeks of gestation is generally recommended.9,10
Regarding the mode of delivery, diamniotic twin pregnancies with the cephalic presentation of the fetus are candidates for vaginal delivery. Planned vaginal delivery was shown to have a similar risk of neonatal mortality/morbidity and maternal morbidity compared to planned cesarean delivery in uncomplicated twin pregnancies.11 The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine recommend that women with twin pregnancies with either cephalic/cephalic twins or cephalic/non-cephalic twins should undergo counseling to attempt a vaginal delivery.12
Women with twin pregnancies who plan to give birth through vaginal delivery without labor pain may undergo labor induction for vaginal delivery. While several reports have shown that induction can be safely performed without increased risk11,13,14, others have reported an increased risk.15-19 Therefore, twin pregnant women should undergo counseling regarding the benefits and risks of labor induction. The prediction of successful induction is a clinically important issue. However, there are few studies on the risk factors for cesarean delivery after IOL in twin pregnancies.
To address this issue, we conducted this study to develop and validate a prediction model for cesarean delivery after IOL in twin pregnancies.