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Updated: Aug 10, 2026

An Experimental Paradigm for the Prediction of Post-Operative Pain (PPOP)
Published on: January 27, 2010
Trial of labor following cesarean delivery
R K Cowan1, R A Kinch, B Ellis
1Department of Obstetrics and Gynecology, John Peter Smith Hospital, Fort Worth, Texas.
Objective:
To examine several variables that may affect the success rate for a trial of labor after previous cesarean delivery, as well as those affecting the rate of uterine rupture.
Methods:
Between June 1, 1990 and December 31, 1991, we performed a consecutive, prospective study of 593 pregnant women who had had at least one abdominal delivery in the past, and attempted a trial of labor in each. Particular attention was given to the success rate of vaginal delivery, the type of previous uterine incision, use of oxytocin, estimated maternal blood loss, 5-minute Apgar scores, and reason for the previous cesarean operation.
Results:
Four hundred seventy-eight patients (81%) had a successful vaginal delivery. Oxytocin induction or augmentation was successful in 46 of 67 (69%) and 117 of 167 cases (70%), respectively. Estimated maternal blood loss was less than 500 mL in 453 cases (95%). Five patients (0.8%) experienced true uterine rupture, resulting in severe neurologic sequelae in one infant. The only consistent indication of uterine rupture was an abrupt and prolonged fetal bradycardia. The majority (463; 97%) of infants who were delivered vaginally had 5-minute Apgar scores of 8 or greater.
Conclusion:
Our success rate of 81% suggests that a trial of labor after previous cesarean delivery is a safe and desirable option, but only after thorough patient counseling. An abrupt and persistent fetal bradycardia may be the only indication that uterine rupture has occurred.

