Induction of labour in patients with prior caesarean births or uterine surgery

Case reports for uterine rupture subsequent to laparoscopic myomectomy were reviewed to determine whether common causal factors could be identified. Published cases were identified via electronic searches of PubMed, Google Scholar, and hand searches of references, and unpublished cases were obtained via E-mail queries to the AAGL membership and AAGL Listserve participants. Nineteen cases of uterine rupture after laparoscopic myomectomy were identified. The removed myomas ranged in size from 1 through 11 cm (mean, 4.5 cm). Only 3 cases involved multilayered closure of uterine defects. Electrosurgery was used for hemostasis in all but 2 cases. No plausible contributing factor could be found in one case [corrected]. It seems reasonable for surgeons to adhere to techniques developed for abdominal myomectomy including limited use of electrosurgery and multilayered closure of the myometrium. Nevertheless, individual wound healing characteristics may predispose to uterine rupture. Copyright © 2010 AAGL. Published by Elsevier Inc. All rights reserved.

Each year in the United States, approximately 60 percent of women with a prior cesarean delivery who become pregnant again attempt labor. Concern persists that a trial of labor may increase the risk of uterine rupture, an uncommon but serious obstetrical complication. We conducted a population-based, retrospective cohort analysis using data from all primiparous women who gave birth to live singleton infants by cesarean section in civilian hospitals in Washington State from 1987 through 1996 and who delivered a second singleton child during the same period (a total of 20,095 women). We assessed the risk of uterine rupture for deliveries with spontaneous onset of labor, those with labor induced by prostaglandins, and those in which labor was induced by other means; these three groups of deliveries were compared with repeated cesarean delivery without labor. Uterine rupture occurred at a rate of 1.6 per 1000 among women with repeated cesarean delivery without labor (11 women), 5.2 per 1000 among women with spontaneous onset of labor (56 women), 7.7 per 1000 among women whose labor was induced without prostaglandins (15 women), and 24.5 per 1000 among women with prostaglandin-induced labor (9 women). As compared with the risk in women with repeated cesarean delivery without labor, uterine rupture was more likely among women with spontaneous onset of labor (relative risk, 3.3; 95 percent confidence interval, 1.8 to 6.0), induction of labor without prostaglandins (relative risk, 4.9; 95 percent confidence interval, 2.4 to 9.7), and induction with prostaglandins (relative risk, 15.6; 95 percent confidence interval, 8.1 to 30.0). For women with one prior cesarean delivery, the risk of uterine rupture is higher among those whose labor is induced than among those with repeated cesarean delivery without labor. Labor induced with a prostaglandin confers the highest risk.

There is concern about the risk of uterine rupture in the subsequent pregnancy after myomectomy. This risk is reported in literature to be around 0.7-1%. The aim of this study was to evaluate the incidence of uterine rupture and associated risk factors in women who had a trial of labor after prior myomectomy.