Low-dose mifepristone 200 mg and vaginal misoprostol for abortion

Contraception. 1999 Jan;59(1):1-6. doi: 10.1016/s0010-7824(98)00150-4.


The objectives of this study were to determine the effectiveness, side effects, and acceptability of one-third the standard 600 mg dose of mifepristone (200 mg) to induce abortion. A prospective trial at seven sites enrolled women > or = 18 years, up to 8 weeks pregnant, and wanting an abortion. The women received 200 mg mifepristone orally, self-administered 800 micrograms misoprostol vaginally at home 48 h later, and returned 1-4 days later for ultrasound evaluation. Surgical intervention was indicated for continuing pregnancy, excessive bleeding, persistent products of conception 5 weeks later, or other serious medical conditions. Of the 933 subjects, 906 (97%) had complete medical abortions, 22 had surgical intervention, two were protocol failures, and three were lost to follow up. Of the 746 subjects who had no or minimal bleeding before misoprostol, 80% bled within 4 h and 98% within 24 h of using misoprostol. By day 7, 95% of women had a complete abortion. Side effects were aceptable in 85% of subjects, and 94% found the procedure acceptable. Low-dose mifepristone followed by vaginal misoprostol was highly effective as an abortifacient.

PIP: The effectiveness, side effects, and acceptability of 200 mg of mifepristone (one-third the standard dose) to induce medical abortion were investigated in a trial conducted at 7 centers in the US. 933 women with pregnancies up to 8 weeks' gestation were enrolled. They were given a 200-mg oral dose of mifepristone to be followed 48 hours later by home administration of 800 mcg of vaginal misoprostol and instructed to return 1-4 days later for ultrasound evaluation. 906 women (97%) experienced complete medical abortion, 22 required surgical abortion, 2 were protocol failures, and 3 were lost to follow-up. The most common indication for surgery was persistent or severe bleeding. Of the 746 women who had little or no bleeding before misoprostol administration, 593 (80%) bled within 4 hours and 731 (98%) within 24 hours of misoprostol. By day 7, 95% of women had experienced a complete abortion. The mean duration of bleeding was 17.4 days. 73% of subjects used an oral narcotic for pain. The most common mifepristone-related side effects were nausea and cramping; misoprostol-related side effects included cramping, fever, and chills. 74% found the pain related to the procedure acceptable and 85% rated its side effects as tolerable. Overall, 94% of subjects rated the medical abortion regimen as acceptable. These findings indicate that low-dose mifepristone is highly effective and acceptable as a self-administered abortifacient. The advantages of a lower dose of mifepristone include reduced manufacturing costs and less exposure to potential side effects.

Publication types

  • Clinical Trial
  • Multicenter Study

MeSH terms

  • Abortifacient Agents, Nonsteroidal / administration & dosage*
  • Abortifacient Agents, Nonsteroidal / adverse effects
  • Abortifacient Agents, Steroidal / administration & dosage*
  • Abortifacient Agents, Steroidal / adverse effects
  • Abortion, Induced / adverse effects
  • Abortion, Induced / methods*
  • Administration, Intravaginal
  • Administration, Oral
  • Adolescent
  • Adult
  • Drug Therapy, Combination
  • Female
  • Gestational Age
  • Humans
  • Mifepristone / administration & dosage*
  • Mifepristone / adverse effects
  • Misoprostol / administration & dosage*
  • Misoprostol / adverse effects
  • Pregnancy
  • Pregnancy Outcome
  • Prospective Studies
  • Self Administration
  • Ultrasonography
  • United States
  • United States Food and Drug Administration
  • Uterus / diagnostic imaging


  • Abortifacient Agents, Nonsteroidal
  • Abortifacient Agents, Steroidal
  • Misoprostol
  • Mifepristone