Objective: This study was undertaken to estimate occurrence and explore clinical predictors of abdominal and vaginal operative delivery in vertex second twin after normal vaginal delivery of the first twin.
Methods: Data from a historical cohort study that was based on a twin registry in the United States (1995-1997) were used.
Results: Among 42,417 vertex second twins following normal vaginal delivery of the first twins, rates of abdominal and vaginal operative delivery were 6.3% and 8.3%, respectively. Cord prolapse, fetal distress, maternal complications, abnormal labor, and birth weight 25% larger than first twin were the most important predicators for operative deliveries. Fetal distress and cord prolapse had a stronger effect on abdominal than vaginal operative delivery.
Conclusion: In general population, abdominal and vaginal operative delivery rates were 6.3% and 8.3%, respectively, in vertex second twin after normal vaginal delivery of the first twin. The most important predictors for operative delivery are cord prolapse and fetal distress.