Misoprostol, a synthetic prostaglandin analog, has become the leading means of terminating pregnancy, especially in the second trimester. In addition to being effective and safe, it is relatively inexpensive and easy to use. It is not clear, however, whether misoprostol is a safe abortifacient or labor-inducing agent after 20 weeks’ gestation in women who have a uterine scar from a previous lower-segment cesarean delivery.
This study evaluated the safety of misoprostol when used to terminate mid-trimester pregnancies in women with a history of at least one previous lower-segment cesarean section. The 80 participants underwent termination for an unwanted pregnancy, missed abortion, fetal anomaly, or fetal death between 13 and 26 weeks’ gestation. The dose of misoprostol was 400 μg up to 20 weeks’ gestation and 200 μg thereafter. Fifty women in each group took misoprostol intravaginally and the other 30 by the sublingual route. The dose was repeated every 6 hours up to a maximum of 24 hours. Woman having termination for similar reasons but lacking a history of cesarean section served as a control group.
Women in the study and control groups were similar demographically. Unwanted pregnancy was the most prevalent indication for termination. The median interval from induction to abortion or delivery was 16.4 hours in study women and 15.6 hours in the control group. No scar rupture or dehiscence was observed, and there were no significant group differences in rates of incomplete abortion, blood loss, or sepsis. In 7 women, antibiotics readily controlled mild sepsis. Two women in each group who responded poorly to misoprostol underwent hysterotomy and salpingectomy.
The investigators conclude that a scarred uterus from one or more previous lower-segment cesarean deliveries does not preclude the use of a prostaglandin analog such as misoprostol to terminate mid-trimester pregnancies.