Induction of labor in twin gestation: can we predict success?

Objective: To identify factors associated with a successful induction of labor in twin pregnancies and associated maternal morbidity. Study design: This was a retrospective review of twin pregnancies >= 24 weeks' gestation undergoing labor induction from 2011 to 2016. The primary outcome was a successful induction of labor. The secondary outcome was a composite of maternal morbidity, including >= 1 of the following: estimated blood loss (EBL) >1500 ml, blood transfusion, hysterectomy, intensive care unit (ICU) admission or maternal death. Results: Of 104 twin pregnancies undergoing labor induction, 64 (61.5%) had a vaginal delivery of both twins. Multiparity [odds ratio (OR) 12.3, 95% confidence interval (CI) 3.9-38.8, P <= 0.005] and maternal age <35 years (OR 2.33, 95% CI 1.1-5.2, P = 0.038) were independently associated with vaginal delivery. The overall rate of composite maternal morbidity was 7.7%. Cesarean delivery (CD) was associated with an increased rate of composite maternal morbidity compared to the successful induction group (17.5% vs. 1.6%, P <= 0.005). An EBL >1500 ml, uterine atony and the use of >= 1 uterotonic agent were more frequent in the CD group. Conclusions: Multiparous women and those <35 years of age were more likely to have a vaginal delivery. Maternal morbidity is increased in women who required a CD after labor induction compared to those who achieved a vaginal delivery.