Effect of indication for previous cesarean section on subsequent delivery outcome in patients undergoing a trial of labor.

During the period January 1 through December 31, 1980, 308 patients who had undergone previous cesarean sections (C/Ss) underwent a trial of labor (TOL). Hospital records of these patients were examined retrospectively in an effort to correlate delivery outcome with the indication for the prior C/S. Patients with a previous C/S for breech had the highest incidence of subsequent vaginal delivery (81 of 94, or 86%), and patients with a previous C/S for cephalopelvic disproportion or failure to progress had the lowest (22 of 64, or 64%). However, the lower rate of vaginal delivery in the latter group was found only among the subpopulation who had never delivered vaginally. Fetal distress does not appear to be a significant recurring factor in patients given a TOL. Exclusion of patients from a TOL after a previous C/S for cephalopelvic disproportion/failure to progress does not appear to be justified.