. "B1. 1993: RU 486--A Decade on Today and Tomorrow." Clinical Applications of Mifepristone (RU486) and Other Antiprogestins: Assessing the Science and Recommending a Research Agenda. Washington, DC: The National Academies Press, 1993.
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Clinical Applications of Mifepristone (RU 486) and other Antiprogestins: Assessing the Science and Recommending a Research Agenda
cologists) to see patients privately, it has been reported that many women prefer to be treated in a group at a medical center (Thong et al., 1992). Research should be conducted to define the best ways to administer the medications under specific conditions. It is certain that requirements for skilled personnel and sterile surgical facilities will be decreased (El-Refaey et al., 1992). The mechanism of action of prostaglandin at low doses indicates that the effect takes place only when progesterone activity has been much decreased by the antisteroid—after more than 24 hours. Whether a combination of RU 486 and prostaglandin to be administered simultaneously will become available is not predictable, since no technology for delayed prostaglandin release is in sight.
Application of this method in developing countries is necessarily more difficult, and local conditions must be considered, including the availability of medical facilities and personnel, cultural traditions (bleeding for several days may be a problem), and the social context. However, women have the right to obtain medical assistance in case of suspected pregnancy, to have the choice to decide to abort, and if so, also to have the choice of either a surgical or a medical method. Whether in developing or industrialized countries, we ought to offer a complete medical choice to women. Even the RU 486 plus misoprostol method may be imperfectly applied for a period of time in certain countries, but it can only be a definite improvement of the present situation. It has also been successfully used for missed abortions and anembryonic pregnancies (El-Refaey et al., 1992). Whether RU 486 plus misoprostol may be used to compensate for the lack of access to family planning and to health facilities is another question. Generally speaking, the best solution is to make available widely accepted and very efficient methods of contraception.
Pregnancy Interruption After Nine Weeks of Amenorrhea
The effects of progesterone, essentially on the decidua (implantation), the myometrium (calming effect), and LH secretion (depressed with lack of ovulation), are observed throughout the course of pregnancy; thus, it is not surprising that an antiprogesterone is potentially useful for pregnancy interruption and labor induction.
In France, voluntary pregnancy interruption is legally permitted until 12 weeks of amenorrhea. When women have passed beyond the current legal limit for RU 486 plus misoprostol treatment (seven weeks), vacuum aspiration is performed. This can be greatly facilitated by RU 486 taken 24 to 48 hours before the procedure—preoperative cervical preparation (ripening) (Henshaw and Templeton, 1991; Urquhart and Templeton, 1990). The cervical ripening may be due not to a change of prostaglandin metabolism in the cervix (Rådestad and Bygdeman, 1992), but to a