MEDICAL ABORTION

Contraception 53:321, 1996

  • Prospective study with 300 women, mean age 27, at < 57d gestation
  • Methotrexate 50mg IM on day 1, then misoprostol 800ug intravag on day 7; if no abortion by day 8, repeat misoprostol dose given
  • 88% of women had complete Ab; 65% during 1st 24h after 1st or 2nd misoprostol dose
  • 23% aborted after mean delay of 24d
  • More effective before 50d gestation than later
  • 44% had nau/vom, diarrhea, HA, dizziness, or hot flashes from methotrexate; 25% from misoprostol
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    NEJM 333:537, 1995

  • 178 women at <64d gestation by menses
  • Methotrexate 50mg/m2 IM; 5-7d later, misoprostol 800ug intravag
  • 86% had complete Ab, us. in <24h; other 14% got 2nd dose misoprostol
  • 4% had no Ab after 2nd dose misoprostol and required suction curretage
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    Can. Med. Assn J. 154:165, 1996

  • 100 women <54d gestation by menses
  • Methotrexate 50mg/m2 IM; 3d later, 800ug misoprostol intravag
  • 48% had complete Ab within 24h; 2 more over next 3d
  • Other 50% got 2nd dose mosiprostol; all but 11 had Ab within 44d
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    Mifepristone (RU-486, Mifeprex)

    Note: Misoprostol is a prostaglandin analogue which causes uterine contractions, resulting in expulsion of the pregnancy; often  used in conjuction with mifepristone

    1. Pharmacology & use
      1. A progestin antagonist; requires misoprostol to generate uterine contractions
      2. Approved in US for termination of intrauterine pregnancies at < 50d gestation
      3. Standard dose = 600mg followed by 400ug misoprostol PO 2d later--Ass'd with complete abortion in 92-97% of pts, 60% within 5h, 70-80% within 24h
      4. Timing of misoprostol: Can be given 1-3d after the mifepristone
      5. Giving the misoprostol intravaginally was ass'd with sig. higher incidence of complete abortion w/o surgical intervention in a randomized trial in 270 women (NEJM 332:983, 1995--Med. Lett.)
    2. Adverse effects
      1. Treatment failure requiring surgical abortion
      2. Heavy bleeding and cramps (typically 1-2wks; can last as long as 1mo; if > 1mo evaluation and possible surgical intervention are indicated; surgical intervention occurs in about 1% of women undergoing medical abortion)
      3. Headache
      4. Nausea, vomiting, diarrhea
      5. Infection-Rare, incidence < 1%
      6. Can cause congenital malformations if abortion fails and pregnancy continues to term
      7. Infants born to women who fail induced abortion with misoprostol may be at increased risk of Mobius' syndrome (congenital facial paralysis) (NEJM 338:1881, 1998--JWWH)
    3. Clinical trials
      1. Series of 575 women who chose medical over surgical abortion at < 9wks gestation at an Edinburgh hospital. 200mg mifepristone PO then intravag prostaglandin analog 36-48h later. 96.4% had successful abortion; 2.1% had suction curretage for continuing preg and 1.5% for retained products. Among pts who chose surgery (similar group), 2.1% required repeat curretage. Medical Ab pts more likely to have heavier-than-nl menses afterward; surgical pts more likely to get abx for suspected endometritis (Br. J. Obs. Gynaecol. 103:1222, 1996-JW)
      2. 2000 women treated with 600mg Mifepristone and 2d later, 400ug misoprostol; succesful termination w/o need for surgical intervention occurred in 92% of those < 50d gestation; 83% of those at 50-56d, and 77% of those 57-63d. Almost all subjhects had some side f/x, primarily abdominal pain and n/v, more at greater gestational ages (NEJM 338:1241, 1998--JW)
      3. 2295 pts at <57d gestation, all receiving mifepristone 200mg PO, randomized to vaginal misoprostol 800ug at 1, 2, or 3d later; f/u u/s done at 8d. no sig. diff in "successful" abortion rates (no evidence of continued pregnancy on u/s at 8d and no need for surgical intervention; 96-98% depending on group) or rates of adverse events (JAMA 284:1948, 2000--abst)