Vaginal birth of twins after a previous Cesarean section

To determine whether a vaginal birth of twins after a Cesarean section carried greater risk than for a singleton gestation as well as determining whether there was a similar likelihood of successful vaginal birth.

A retrospective study was carried out of all twin pregnancies in which vaginal birth was attempted after a Cesarean section, in 1991-99. The next three consecutive singleton pregnancies in which vaginal birth was attempted after a Cesarean section were also evaluated. Comparisons were made for successful vaginal birth after Cesarean section complications (blood loss, uterine rupture or dehiscence, hysterectomy, chorioamnionitis and neonatal morbidity). Where appropriate, X2 tests of association or Student's t tests were used. Significance was set at p < 0.05.

A total of 19 twin pregnancies met the study criteria. There were 57 controls. Gestational ages differed slightly (twin pregnancies, 36.3 weeks; controls, 39.3 weeks). The success rate of vaginal birth after Cesarean section was 84.2% for twin pregnancies and 75.4% for controls. The incidence of postpartum hemorrhage was 5.3% for both groups. One uterine rupture occurred in the control group; none occurred in the twin pregnancy group. One uterine dehiscence occurred in each group. No significant differences were found for any of the other parameters tested.

The option of vaginal birth of twins after Cesarean section appears to have a similar risk and shares a similar likelihood of success to those of a singleton pregnancy. In view of the lack of increased complications, this option can be offered to patients with twin pregnancies who are eligible for vaginal birth after Cesarean section.