The steroid RU-486 (mifepristone) is an antiprogesterone that works at the receptor level. It can interrupt pregnancy very early on (contragestion), mostly by interfering with the process of implantation and decidua function. It also may facilitate surgical evacuation of the uterus and certain difficult deliveries. It impedes ovulation when taken during the follicular phase. Also, RU-486 is the first antiglucocorticosteroid available for clinical use. It deserves further studies to assess its wide range of therapeutic potential.
KIE: The steroid RU 486, developed by French researchers, has been the subject of controversy in Europe and in the United States because of its use as an abortifacient during the early stages of pregnancy. Baulieu, in whose laboratory RU 486 was developed and who himself is a consultant to its manufacturer, describes the development and testing of the steroid and some of its potential uses. According to Baulieu, RU 486 facilitates late first trimester abortion, therapeutic abortion during the second and third trimesters, and the delivery of dead fetuses. It also may have applications in certain cases of difficult childbirth, and in contraception. Baulieu argues for further study of RU 486 and for its immediate availability for certain aspects of patient care.