Mifepristone in Combination with Misoprostol vs. Low Dose Mifepristone Alone in Emergency Contraception: a Multi-center Double-blind Randomized Clinical Trial

摘要

To compare the effectiveness and side effects of various low dose of Mifepristone in combination with Misoprostol and low doses Mifepristone alone in emergency contraception Materials & Methods This is a multi center double blind randomized controlled clinical trial. A total of 899 healthy women were allocated into this study and were randomly divided into 3 groups. They were orally administrated with different emergency contraceptives with 120 h after unprotected intercourse. Group I (n=300) was given 25 mg Mifepristone plus 0.2 mg Misoprostol after 24 h. Group II (n=299) was given 10 mg Mifepristone plus 0.2 mg Misoprostol after 24 h. Group III (n=300) was administrated with 10 mg Mifepristone alone. The effective rates in different groups were calculated with Dixon method. Results Altogether 11 pregnancies occurred, among which 2 cases were in Group I, 2 cases in Group II, and 7 cases were in Group III. After correction with method failure, there was only one case in Group I, 0 case in Group II, and 5 cases in Group III. The contraceptive effectiveness in these groups was 95.5%, 100% and 76.9% respectively. The pregnancy rate was significantly lower in Group I and Group II than that of Group III (P0.05). Conclusion Use of low dose Mifepristone (25 mg or 10 mg) in combination with 0.2 mg Misoprostol was an effective, low side effects and safe treatment regimen for emergency contraception.