Early Termination of Pregnancy with Mifepristone (RU 486) and the Orally Active Prostaglandin Misoprostol

Mifepristone (RU 486) is a potent antiprogestin, but when it is administered alone in early pregnancy, termination of the pregnancy is incomplete in 20 percent or more of women 1 – 3 . This relative lack of efficacy may be due to an insufficient increase in the prostaglandin concentration in the uterus to allow completion of the abortion 4 , 5 . The efficacy of prostaglandin to complement the antiprogesterone effect of mifepristone for the voluntary termination of early pregnancy is well established 4 , 6 – 9 . The rationale for the sequential administration of the two drugs 4 , 5 is that the prostaglandin analogue increases uterine . . .