Trial of labor in patients with a previous lower uterine vertical cesarean section.

OBJECTIVE: Our purpose was to determine the efficacy and safety of a trial of labor in patients previously delivered at least once by a lower uterine vertical cesarean section.

STUDY DESIGN: A retrospective review was performed at a single tertiary perinatal center, The University of Florida Health Science Center, Jacksonville. The medical records of all patients with a previous low vertical cesarean section who underwent a trial of labor during a 72-month period from January 1988 until December 1993 were reviewed. The medical records of the next two patients who did not have a prior uterine incision admitted to labor and delivery after the index case served as the controls. The duration and outcome of labor, including mode of delivery, maternal and perinatal morbidity, and birth trauma were evaluated.

RESULTS: Of 77 patients with a previous low vertical cesarean incision, 11 (14.3%) had a repeat operation compared with 14 of 154 patients (9.0%) in the no previous cesarean section group (not significant). No differences were noted in the incidences of operative vaginal deliveries or prolonged duration of the first or second stages of labor, or in the rate or maximum dose of oxytocin infusion between the two groups. One patient in the previous cesarean section group had uterine rupture. The incidence of umbilical artery pH < or = 7.20 was similar. No difference in the number of infants with 1- or 5-minute Apgar scores < or = 7 was noted.

CONCLUSION: A trial of labor in women with previous low vertical cesarean sections results in an acceptable rate of vaginal delivery and appears safe for both mother and fetus.