Trial of labor after cesarean delivery: the effect of previous vaginal delivery.

Abstract

This study examined the effects of order of previous modes of delivery on the rate of cesarean delivery and duration of a trial of labor among women with a history of 1 previous cesarean delivery and 1 previous vaginal delivery. The medical records of 4393 women at our institution who were seen June 1984-July 1996 for a trial of labor after a previous cesarean delivery were abstracted. The 800 women with a history of 1 previous cesarean and 1 previous vaginal delivery were included in this analysis. They were split into 2 groups by obstetric history: (1) 1 cesarean delivery followed by 1 vaginal delivery (vaginal last) and (2) 1 vaginal delivery followed by 1 cesarean delivery (cesarean last). Patient characteristics, durations of labor, and rates of cesarean delivery were compared with chi2 analysis, the Student t test, and the Wilcoxon rank sum test. Possible confounding variables were controlled for with multivariate logistic regression. The rates of cesarean delivery for the vaginal last and cesarean last groups were 7.2% and 14.7%, respectively (P = .002). The median durations of labor for the vaginal last and cesarean last groups were 5.6 and 7.0 hours, respectively (P = .01). The differences in cesarean rates and durations of labor were seen regardless of the indication for the previous cesarean delivery. Among women with 1 previous cesarean and 1 previous vaginal delivery, those whose most recent delivery was vaginal had a lower rate of cesarean delivery and shorter duration of labor than did those whose most recent delivery was cesarean.