Epidural analgesia. Effect on the likelihood of a successful trial of labor after cesarean section.

From October 1984 to April 1986, 237 women who had had an earlier cesarean section underwent a trial of labor (TOL). The delivery outcomes for 87 who received epidural analgesia were compared retrospectively with those for the 150 who did not. There were no overt uterine ruptures. The rates were similar for successful TOL, uterine scar dehiscence, blood transfusions, endometritis and one- and five-minute Apgar scores. The rate of operative vaginal delivery was higher in the epidural group. When epidural subjects were divided into vaginal and cesarean delivery groups, the failed-TOL group differed from the successful-TOL group in greater maternal weight gain, heavier and longer infants, higher rate of oxytocin administration, less cervical dilation and higher station at epidural activation. When the oxytocin-treated subjects were excluded, however, the epidural and no-epidural patients had the same successful TOL rates (94% and 92%, respectively) and spontaneous vaginal delivery rates (70% and 76%, respectively). Epidural analgesia, when controlled for oxytocin use, appears to have no effect on the failed-TOL or operative vaginal delivery rate.