Misoprostol Induction of Labor Among Women with a History of Cesarean Delivery

Objective: Several reports have appeared of uterine rupture among women with a history of cesarean delivery who received misoprostol for induction of labor. A recent review suggested a uterine rupture rate of almost 6%, but the experience at our institution did not seem to reflect this high complication rate. This study was undertaken to compare complications of labor induction with misoprostol between women with a history of cesarean delivery and women without uterine scarring.

Study Design: A computerized database was used to select women with a viable fetus who underwent induction of labor with misoprostol during the period from January 1996 through December 1998. Patients were given 50 microg misoprostol every 4 hours. Women with a history of cesarean delivery were retrospectively compared with those without uterine scarring.

Results: A total of 425 women were given misoprostol for induction of labor: 48 had a history of cesarean delivery and 377 did not. Women with a history of cesarean delivery were more likely to be delivered abdominally (56% vs 28%; P <.04). Among women with a history of cesarean delivery, women who had a history of vaginal birth after cesarean were more likely to be delivered vaginally (92% vs 42%; P =.003). There was no difference in the overall rate of complications (2% with scarring vs 3% without scarring). There were no uterine ruptures. However, the previous cesarean group was more likely than the unscarred group to have blood loss >500 mL (38% vs 22%; P <.03). Although the incidences of fetal distress were similar, neonates born to women in the previous cesarean group were more likely to have an Apgar score <7 at 5 minutes (13% vs 5%; P <.04).

Conclusion: Misoprostol induction of labor in women with a history of cesarean resulted in a higher rate of cesarean delivery than was seen among women without uterine scarring but was not associated with a higher incidence of complications. There were no uterine ruptures in either group.