Fertility control with RU 486

Studies on the post-coital contraceptive mechanisms of crude extract of Sri Lankan marine red algae, Gelidiella acerosa

This study investigates the potential post-coital contraceptive mechanisms of the crude extract of Sri Lankan marine red algae, Gelidiella acerosa, using rats. The dose used was 1000 mg/kg/day and the route of administration was oral. The results showed that the crude extract possessed potent post-coital contraceptive activity when administered on days 7-8 of pregnancy indicating the presence of a narrow window in its action. The post-coital contraceptive activity was due to an elevated post-implantation loss (by 89%) resulting from fetal death between days 9-14 of pregnancy. The extract was neither estrogenic nor anti-estrogenic nor stressor but appeared to be anti-progestational (reduced ovarian progesterone output). It is suggested that the crude extract may reduce the ovarian progesterone release possibly via anti-platelet and PGE2-depressing activity.

The abortion pill: a solution for unsafe abortions in developing countries?

The abortion pill is a new abortion technique which does not require technically skilled health personnel. Several clinical researchers have stated that the ease of administration of the abortion pill gives it the potential to save lives in countries where thousands of women die annually from complications of failed abortions due to poor health services. This article discusses medical and users' aspects of the abortion pill, with particular emphasis on its use in developing countries, and questions the usefulness of the abortion pill in areas where health care facilities are in short supply. It stresses the need to consider the social, cultural and health care context in which the abortion pill will be used before it is sold on the world market. The safety and efficacy of the abortion pill could be adversely affected by the way women perceive its effectiveness, women's beliefs about conception and pregnancy, and their health status. In the present two-phase administration form the abortion pill is not likely to be appropriate for use in developing countries with a shortage of health care facilities.

Predictors of failed attempted abortion with the antiprogestin mifepristone (RU 486)

The experience of 271 patients who received mifepristone (RU 486) in experimental protocols from July 1984 to January 1989 was analyzed by logistic regression methods. The regimen used was the strongest predictor of failure, followed by Quetelet's index and initial beta-human chorionic gonadotropin level. The relative risk of failure was 2.3 times with 7-day regimens and 6.3 times with the other regimens that obtained with regimens of 600 mg given once or twice. The relative risk of failure increased with increasing Quetelet's index; women in the top quartile were 2.9 times more likely to fail to abort than were women in the bottom quartile. The risk of failure increased with increasing initial beta-human chorionic gonadotropin level; those with an initial level greater than 19,800 mIU/ml were 2.8 times more likely to fail to abort than were women with an initial value less than or equal to 6350 mIU/ml. Body mass appears to influence the likelihood of abortion with mifepristone.

Voluntary interruption of pregnancy with mifepristone (RU 486) and a prostaglandin analogue. A large-scale French experience

In 2115 women seeking voluntary termination of pregnancy after 49 days of amenorrhea or less, we studied the effect of a single 600-mg dose of mifepristone (RU 486), followed 36 to 48 hours later by the administration of one of two prostaglandin analogues, either gemeprost (1 mg by vaginal suppository) or sulprostone (0.25, 0.375, or 0.5 mg by intramuscular injection). The women were monitored for four hours after prostaglandin administration. Efficacy was indicated by the complete expulsion of the conceptus without the need of an additional procedure. All other results were considered failures, and the pregnancy was then terminated by a surgical method. The overall efficacy rate was 96.0 percent (95 percent confidence interval, 95.0 to 96.8). The failures included persisting pregnancies (1.0 percent), incomplete expulsions (2.1 percent), and the need for hemostatic procedure (0.9 percent). The mean time to expulsion was significantly shorter when sulprostone was given in the high dose (4.5 hours) than when it was given in the two lower doses (13.1 and 19.3 hours) or when gemeprost was given (22.7 hours). The mean duration of uterine bleeding was 8.9 days (range, 1 to 35); one woman received a blood transfusion. Most women had transient abdominal pain after receiving prostaglandin, but there were few other side effects. We conclude that the administration of mifepristone followed by a small dose of a prostaglandin analogue is an effective and safe method for the early termination of pregnancy.

Low dose RU486 prevents progesterone antagonism on uterine growth and concomitant type II oestradiol binding induction by oestradiol in rats

The effect of RU486, a synthetic antisteroid, on the antagonism of progesterone (Pg) and dexamethasone (Dex) against oestradiol (Oe) induced uterine growth, and on uterine oestradiol binding (type I and type II sites) was studied in ovariectomized CFY rats. Changes of hypothalamic low affinity [3H]Oe binding have also been evaluated. Inhibitory effects of Pg but not of Dex on uterine growth and type II Oe binding site induction were prevented by RU486. Antiprogestin effect of RU486 could also be demonstrated on low affinity [3H]Oe binding in hypothalami. The inhibitory effect of dexamethasone on type II Oe binding was not opposed by antisteroid, on the contrary, RU486 seemed to potentiate this effect of Dex. Evaluation of type I binding was complicated by the distorting effect of type II binding at the saturation curve. Changes of type I binding seemed to parallel those of type II binding except after Oe+Dex treatment where an increased level of uterine cytoplasmic type I sites and a simultaneous decrease of type II sites were found. Blockage of [3H]Oe binding at high RU486 concentrations was found in vitro in the uterine cytoplasmic fraction. A less pronounced effect was observed in the nuclear fraction. Possible mechanisms of the RU486 effect on type II Oe binding are discussed.