Reduced Misoprostol Regimen versus Standard Misoprostol Regimen for Induction of Second Trimester Abortion in Patients with Previous Cesarean Section Scar

Background: There has been a debate concerning the use of misoprostol for mid-trimester (13-26 weeks) pregnancy termination in women with prior cesarean scars due to concerns regarding a potential higher risk of uterine rupture. 
Objectives: To evaluate the efficacy and safety of two misoprostol regimens (400 mcg misoprostol versus 200 mcg misoprostol) for 2^nd-trimester pregnancy termination in individuals with a prior cesarean section scar.
Patients and methods:  A prospective randomized study included one hundred and seventy-six patients at 13-26 weeks gestation with previous one cesarean section who were scheduled for pregnancy termination using misoprostol. Participants were randomly divided into two equal groups. Group A (standard misoprostol regimen, 88 patients) received 400 mcg of misoprostol vaginally every 4 hours until the fetus was expelled, and Group B (reduced misoprostol regimen, 88 patients) received 200 mcg of misoprostol vaginally every 4 hours until the fetus was expelled. Primary outcomes were time to abortion and complete abortion rates, secondary outcomes were side effect and complications.
Results: There was no significant difference between the two groups regarding demographic data. The only documented advantage of standard misoprostol regimen in the current study was significantly shorter induction-abortion interval (28.26 ±2.52 hours) versus 36.6±2.16 hours in reduced misoprostol group. However, reduced misoprostol regimen has comparable complete abortion rates to standard misoprostol regimen with no significant difference (75% and 84.1% respectively, p=0.13). Additionally, there were no significant differences between groups regarding the need of curettage for incomplete abortion.  
Conclusion: Low-dose vaginal misoprostol administration seems to be beneficial for terminating a 2^nd-trimester pregnancy in women with a prior cesarean scar without causing side effects or complications.