Previous cesarean section: the risks and benefits of oxytocin usage in a trial of labor.

Permitting a trial of labor in patients with a previous cesarean birth is rapidly becoming an accepted alternative to routine elective repeat cesarean section. As interest in this approach has grown and the risks associated with a trial of labor have been better defined, the use of oxytocin in these patients emerges as a pertinent issue. Our retrospective experience of oxytocin use in patients undergoing a trial of labor suggested no increased maternal or fetal risk compared to patients who did not receive oxytocin. On the basis of our prior experience, we set out to investigate prospectively the role of oxytocin in 732 patients with prior cesarean section who underwent a trial of labor. During the study period, 289 (40%) patients received oxytocin for either induction (32, 11%) or augmentation (257, 89%) of labor and 443 patients did not receive oxytocin. Successful vaginal delivery was achieved in 200 patients (69%) as opposed to 395 (89%) of the patients who did not receive oxytocin. The incidences of dehiscence in the oxytocin and no oxytocin groups were 3% and 2%, respectively. Further analysis of vaginal and cesarean delivery complications for the two groups were contrasted and no significant differences were found with respect to the incidence of hemorrhage, uterine atony, hysterectomy, or the requirement of transfusions. Neonatal outcome was also comparable for both groups. On the basis of our prospective experience, it appears that the use of oxytocin, when carefully monitored, is a safe and reasonable consideration in the patient undergoing a trial of labor.