Termination of pregnancy in patients with previous cesarean section

To evaluate the safety and efficacy of termination of pregnancy using mifepristone and misosprostol at more than 15 weeks' gestation in patients with uterine scar due to previous cesarean section.

This retrospective study was conducted in a tertiary maternity ward between January 2000 and October 2004. A total of 252 women at more than 15 weeks' gestation underwent termination of pregnancy including 50 women with uterine scar due to previous cesarean section (Group 1) and 202 control patients (Group 2) without known uterine scar. Abortion was induced with mifepristone and a prostaglandin analogue. Women between 15 and 34 weeks' gestation received misoprostol intravaginally every 3 h at doses of 200 microg (Group 1) or 400 microg (Group 2). Women at more than 34 weeks' gestation received Prostin E2 vaginal gel. Main end points were hemorrhage, fever, retained placenta, occurrence of complications including uterine rupture and dehiscence, and final outcome.

A total of 13 (26%) patients in Group 1 and 79 (39.1%) in Group 2 were at more than 24 weeks' gestation. The abortion failure rate was 2% (1/50) in Group 1 and 0.5% (1/202) in Group 2 (p = .28). The median induction-to-delivery interval was 8.5 h (range, 3.0-114.2 h) for Group 1 and 9.0 h (range, 1.3-124.3 h) in Group 2 (p = .26). One case of uterine rupture and one case of dehiscence were observed, both in women in Group 1. The incidence of hemorrhage was not significantly different between Group 1 and Group 2 (2% vs. 0.9%, respectively, p = .56). The incidence of retained placenta was higher in the Group 1 (70% vs. 52.5%, respectively, p = .025).

In this retrospective series of women who underwent abortion at 15-35 weeks' gestation using mifepristone and a prostaglandin analogue for labor induction abortion, history of cesarean section was not associated with higher morbidity except risk of uterine rupture. However, dose and interval of misoprostol should be determined. A larger study is needed before drawing definitive conclusions about the safety of these regimens.