Mifepristone blocks the action of progesterone, which is needed to sustain a pregnancy.
Three clinic visits are required - one more visit than is necessary for a surgical abortion. Most side effects experienced are due to the prostaglandin. What women can expect from a mifepristone abortion It will take three visits to complete the procedure. Some women may see pregnancy tissue. 60 percent of women will have an abortion within four hours of receiving the prostaglandin.