Misoprostol Dosing for First-Trimester Abortion

The first review evaluated all options for the medical treatment of spontaneous abortion and included five RCTs of single-dose misoprostol regimens.1 One RCT (n = 198) comparing vaginal and oral misoprostol, 800 mcg, found similar success rates for complete uterine evacuation (relative risk [RR] = 0.94; 95% CI, 0.76 to 1.16). In individual comparisons (unknown number of trials or patients), the authors found no significant differences in effectiveness between vaginal misoprostol, 800 mcg, vs. sublingual misoprostol, 600 mcg (RR = 1.01; 95% CI, 0.86 to 1.19); vaginal misoprostol, 800 mcg, vs. vaginal misoprostol, 600 mcg (RR = 1.22; 95% CI, 0.93 to 1.59); or vaginal misoprostol, 600 mcg, vs. sublingual misoprostol, 600 mcg (RR = 1.23; 95% CI, 0.99 to 1.55). MISOPROSTOL PLUS MIFEPRISTONE A 2011 systematic review and meta-analysis evaluating medical therapeutic abortion in the first trimester found that oral dosing was the least effective route of administration.3 The included RCTs used misoprostol in combination with mifepristone.