219: Prediction of successful twin vaginal birth: A secondary analysis of the twin birth study


      To identify maternal and fetal characteristics associated with successful twin vaginal birth.

      Study Design

      This was a secondary analysis of the Twin Birth Study, a prospective randomized-controlled trial of 2804 women with diamniotic twin pregnancies > 32 weeks gestation with a cephalic presenting twin, randomized to planned cesarean or planned vaginal delivery. Women randomized to planned vaginal delivery were considered in this secondary analysis. Patients were analyzed in two cohorts: successful vaginal delivery (of both twins), and unsuccessful vaginal delivery (cesarean of one or both twins). The cohorts were compared to identify differences in maternal and fetal characteristics associated with successful vaginal delivery. Multivariate logistic regression was performed to calculate adjusted odds ratios and 95% confidence intervals for each characteristic that differed significantly between the cohorts.


      Overall, 1,406 women were randomized to the planned vaginal delivery group, of which 1,393 women were included in the final analysis. Out of these women, 783 (56.2) women had a vaginal delivery for both twins, 59 (4.2) women had a vaginal delivery of the first twin followed by a cesarean delivery for the second twin, and 551 (39.6) women underwent a cesarean delivery for both twins. After accounting for confounders, factors found to decrease the likelihood of vaginal delivery for both twins were advanced maternal age, hypertensive disorders, maternal diabetes, prior cesarean delivery and breech presentation of the second twin. Prior vaginal delivery increased the likelihood of vaginal delivery of both twins (Table).