Twin TOLAC is an independent risk factor for adverse maternal and neonatal outcome.

Purpose: To determine factors associated with a successful twin trial of labor after Cesarean delivery (TOLAC).

Methods: A retrospective cohort study was conducted at a single medical center in a population highly motivated for TOLAC (> 80%). The effect of maternal demographic and obstetric characteristics on the likelihood of twin TOLAC success was analyzed. Maternal complications and combined adverse outcome (uterine rupture, Apgar < 7 at 5 min, and umbilical cord pH < 7.1) were compared between singleton and twin TOLAC groups.

Results: Ninety-five women with a twin gestation and one previous Cesarean delivery comprised the study group. Five thousand seven hundred and three women with a singleton gestation and one previous Cesarean delivery comprised the control group. 30.5% and 83% of women with twin and singleton gestation, respectively, underwent a trial of labor. Women in the twin TOLAC group were significantly less likely to succeed and less likely to have a spontaneous unassisted vaginal delivery compared to women in the singleton TOLAC group. Maternal age less than 35 years, parity greater than two, and at least one previous VBAC increased the likelihood of TOLAC success. Statistically significant differences were found between the twin TOLAC and the singleton TOLAC group for uterine rupture, maternal complications, and for combined adverse outcome.

Conclusions: Twin TOLAC is not common, even in parturients highly motivated for TOLAC. Our results demonstrate that even in a selected population, women undergoing twin TOLAC are less likely to have a successful spontaneous vaginal delivery and have a higher risk for uterine rupture, maternal complications, and combined adverse perinatal outcome than women undergoing TOLAC with a singleton gestation. Demographic and obstetric risk factors were identified which can aid the attending obstetrician in the counseling of these challenging cases.