[Knowledge about "morning-after pill" should be spread to all women. Comments on meta-analysis of postcoital contraception].
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Contraceptives, Postcoital↗
Biomedical subjects
K G Danielsson
Publications and source records attributed to K G Danielsson.
[The interplay between embryo and endometrium is important for successful implantation. Increased knowledge can result in new contraceptive methods and better treatment of infertility].
It seems likely that local factors such as cytokines play an important role in synchronizing the development of the embryo and the gestational tract and in determining pregnancy outcome. Evaluation of the precise sequence of cytokines to which the embryo is exposed and responds during the critical periimplantation period may also make it possible to develop culture media which will improve embryo viability and hence increase implantation rates in IVF programs. In addition, an in vitro three-dimensional culture system is being developed which closely resembles endometrium in vivo. This system offers an opportunity to study the local molecular events involved in blastocyst adhesion and to elucidate the role played by local factors, such as cytokines, in producing a receptive luminal epithelium.
Blastocyst↗
Medical termination of early pregnancy: the Swedish experience.
Abortion has been legal up to the 22nd week of gestation in Sweden since 1975. Most women terminate their pregnancies early; 96% before the 12th week and 75% in less than 63 days. Termination of early pregnancy (up to 63 days' gestation) using mifepristone followed by gemeprost was approved in Sweden in 1992. Use of the medical method has slowly but steadily increased since then. Currently about 40% of the women eligible for the procedure choose it. Both the surgical (vacuum aspiration) and the medical methods are regarded as effective and safe. The medical method will not replace vacuum aspiration, but be an alternative to it.
Abortifacient Agents, Nonsteroidal↗
Comparison between oral and vaginal administration of misoprostol on uterine contractility.
OBJECTIVE: To compare the degree of absorption and the effect on uterine contractility of the prostaglandin E1 analogue misoprostol after vaginal and oral administration. METHODS: Thirty women with a normal intrauterine pregnancy between 8 and 11 weeks' gestation who requested termination of pregnancy were given either 0.2 mg (orally n = 5; vaginally n = 6) or 0.4 mg (orally n = 10; vaginally n = 9) of misoprostol. Intrauterine pressure was recorded using a Grass polygraph connected to a pressure transducer 30 minutes before misoprostol was given and for 4 hours thereafter. At the end of the recording, suction curettage was performed. Blood samples were obtained at 0, 0.5, 1, 2, 4, and 6 hours for measurement of misoprostol, which was assayed by high-pressure liquid chromatography-mass spectrometry. RESULTS: In all patients, the first effect was an increase in uterine tonus. After 0.4 mg of misoprostol administered orally, uterine tonus started to increase after a mean (+/- standard deviation) time of 7.8+/-3.0 minutes and reached its maximum after 25.5+/-5.0 minutes. The corresponding times after vaginal administration were 20.9+/-5.3 minutes and 46.3+/-20.7 minutes, respectively. The initial increase in tonus was also more pronounced after oral than after vaginal administration. After vaginal administration, all patients developed uterine contractions; the activity, measured in Montevideo units, increased continuously during the observation period. This was not the case after oral administration. Plasma levels of misoprostol were measured in 18 patients. The highest levels were found 30 minutes after oral treatment and 1-2 hours after vaginal administration. CONCLUSION: The long-lasting and continuously increasing uterine contractility after vaginal administration can be explained only in part by a direct effect of misoprostol. The longer period of elevated plasma levels of misoprostol may also have initiated the prolonged events leading to increased uterine contractility.
Abortifacient Agents, Nonsteroidal↗
Contraceptive efficacy of daily administration of 0.5 mg mifepristone.
The antiprogestin mifepristone has shown potential to be used as a contraceptive. If 200 mg mifepristone is administered immediately after ovulation, the endometrium shows sufficient impairment of secretory development to prevent implantation. Low daily doses of mifepristone have been shown to reduce several of the local factors regarded as crucial for implantation in human endometrium. To find out if this regimen is sufficient to prevent pregnancy, 32 women were recruited for a study where 0.5 mg mifepristone was administered daily. A total of 141 cycles were studied. Five pregnancies occurred, which was significantly less than if no contraceptive method had been used. However, the dose chosen did not seem sufficient to act as a contraceptive although it is probably not possible to increase the dose without disturbing ovulation and bleeding pattern.
Adult↗
Expression of cyclo-oxygenase in human endometrium during the implantation period.
Prostaglandins (PG) are known to be involved in the process of human implantation. In several animal species treatment with prostaglandin synthesis inhibitors will prevent implantation. Cyclo-oxygenase (COX) is the rate-limiting enzyme in the synthesis of PGs and exists in two isoforms, COX-1 and COX-2. Defective implantation in COX-2-deficient mice has been demonstrated recently. In the present study, the expression of COX-1 and COX-2 was studied during the implantation period in healthy fertile women before and after treatment with the antiprogesterone, mifepristone. The study consisted of one control cycle and one treatment cycle. The subjects served as their own control. During the treatment cycle the subjects received 200 mg of mifepristone 2 days after the luteinizing hormone (LH) surge. Endometrial biopsies were obtained in the mid-luteal phase (LH + 6 to LH + 8) in both cycles. Using polyclonal antibodies against COX-1 and COX-2, immunostaining for COX-1 was found mainly in the glandular and luminal epithelium and for COX-2 mainly in the luminal epithelium and the perivascular cells. After treatment with mifepristone, expression of COX-1 in glandular epithelium and COX-2 in luminal epithelium significantly decreased whilst the immunostaining for COX-2 in the perivascular cells remained strong. This study shows the expression of both COX-1 and COX-2 during the implantation period and also indicates that treatment with mifepristone in early luteal phase impairs glandular epithelial function and endometrial receptivity.
Animals↗
Contraceptive use of antiprogestin.
OBJECTIVES: To study the effect of antiprogestin on ovarian function and endometrial development during the menstrual cycle and the possibility of using these compounds for contraceptive purposes. METHODS: Administration of different doses of the antiprogestin mifepristone during the menstrual cycle; intermittent measurements of luteinizing hormone, progestin and estrogen in blood and/or urine; endometrial morphology and concentration of markers for endometrial receptivity; efficacy trials of the contraceptive effect of mifepristone. RESULTS: A high dose of mifepristone administered in the follicular phase will inhibit follicular development. If mifepristone is given immediately after ovulation, the secretory development of the endometrium and the expression of, for instance, leukemia inhibitory factor and integrins will be inhibited. Similar effects on the endometrium are obtained with small weekly doses (2.5 or 5.0 mg) or small daily doses (0.5 mg) of mifepristone, which do not inhibit ovulation. Once-monthly administration of 200 mg mifepristone on the day after ovulation, and emergency postcoital treatment, are highly effective methods for preventing pregnancy. Even 5 mg once weekly has a significant contraceptive effect. CONCLUSIONS: The antiprogestin mifepristone has a number of effects during the menstrual cycle which makes the compound suitable for contraceptive use. Treatment after a single act of unprotected intercourse, and once-a-month treatment immediately after ovulation, have shown high contraceptive efficacy. A low-dose regimen which does not influence ovulation also has a contraceptive effect, but the efficacy needs to be improved before routine clinical use.
Contraceptives, Oral, Synthetic↗
Contraceptive efficacy of low doses of mifepristone.
OBJECTIVE: To determine whether a 5-mg dose of mifepristone is sufficient to prevent pregnancy. DESIGN: Clinical study. SETTING: Academic research center. SUBJECT(S): Healthy, fertile, sexually active female volunteers. INTERVENTION: Volunteers received a 5-mg dose of mifepristone once weekly, starting on cycle day 2, for up to 6 months. This was their only contraceptive method. MAIN OUTCOME MEASURE(S): Number of pregnancies. RESULT(S): The treatment resulted in a significant decrease in pregnancy rate without affecting the menstrual cycle or causing disturbing side effects. CONCLUSION(S): A low dose of mifepristone, which does not inhibit ovulation, reduces fertility significantly by affecting the endometrium. However, the contraceptive effect needs to be improved for the drug to compete with other contraceptive methods.
Adult↗
Effect of low daily doses of mifepristone on ovarian function and endometrial development.
The effects of low daily doses of the antiprogestin mifepristone (RU 486) on ovarian and endometrial function were studied. The study included one control cycle, three treatment cycles and one follow-up cycle. During the treatment cycles, either 0.1 (n = 5) or 0.5 (n = 5) mg of mifepristone was administered once daily. Urine samples were collected three times weekly during the control and treatment cycles and pregnanediol glucuronide and oestrone glucuronide and luteinizing hormone (LH) were quantified by radioimmunoassay. Blood samples for cortisol measurement were collected once weekly and for serum glycodelin at the onset of menstruation. An endometrial biopsy was obtained in the mid-luteal phase in the control cycle and in the first and third treatment cycles and analysed by morphometric and histochemical methods. Binding of Dolichus biflorus agglutinin (DBA) lectin was measured and expression of progesterone and oestrogen receptors and glycodelin were analysed immunohistochemically. All cycles studied were ovulatory with an LH peak and elevated pregnanediol glucuronide concentrations. Follicular development seemed normal as judged by ultrasound examination. The length of the menstrual cycle and the menstrual bleeding were not significantly altered. Following administration of 0.5 mg mifepristone/day, endometrial development appeared to be slightly retarded and glandular diameter was significantly reduced. Furthermore, significant decreases in DBA lectin binding and endometrial expression of glycodelin were observed. Daily doses of 0.1 mg did not have any significant effect on the endometrium. No differences in oestrogen or progesterone receptor immunoactivity between control and treatment cycles were seen. This study provides further evidence that endometrial function is sensitive even to doses of antiprogestin that are low enough not to disturb ovulation. It remains to be established whether these effects are sufficient to prevent implantation.
Adult↗
The effect of various doses of mifepristone on endometrial leukaemia inhibitory factor expression in the midluteal phase--an immunohistochemical study.
Leukaemia inhibitory factor (LIF) is a cytokine which plays an obligatory role in mouse blastocyst implantation. In human endometrium, LIF expression is significantly increased in the mid-luteal phase indicating that LIF may also play an important role in the human. We have previously shown that a single dose of 200 mg of mifepristone immediately post-ovulation is an effective contraceptive method, probably due to inhibition of endometrial development and function. The purpose of this study was to investigate the effect of various doses of mifepristone on endometrial LIF expression. A total of 22 fertile, regularly-menstruating women were studied during control and treatment cycles. The subjects were divided into four groups: group I received a single dose of 200 mg of mifepristone on cycle day LH + 2 (n = 7). The subjects in groups II and III were treated with either 5 mg (n = 5) or 2.5 mg (n = 5) once a week for 2 months. Group IV subjects received 0.5 mg per day (n = 5) of mifepristone for 3 months. LIF was measured immunohistochemically in endometrial tissue specimens taken on the corresponding day (cycle day LH + 6 to LH + 8) in hormonally-characterized control and treatment cycles. LIF immunostaining was observed in all controls and located to the cytoplasm of the luminal and glandular epithelial cells and stromal cells. In the treatment cycles the staining of luminal epithelium and stroma was similar to controls, while the glandular staining was reduced in all treatment groups. This study reveals that early luteal phase treatment as well as intermittent or daily low dose treatment with mifepristone reduces endometrial glandular LIF expression at the expected time of implantation. The results further support the contraceptive potential of mifepristone in low doses.
Adult↗
The possible use of antiprogestins for contraception.
BACKGROUND: A number of compounds, antiprogestins, e.g. mifepristone, onapristone and lilopristone, have been developed which compete with progesterone at the receptor level. One of these, mifepristone, is in combination with a prostaglandin analogue currently in use for termination of early pregnancy. The possibility to use these compounds for contraceptive purposes is presently under evaluation. METHODS: The possible contraceptive effect of antiprogestins has been evaluated in both clinical and experimental studies. RESULTS: Administration of antiprogestin during the follicular phase has an inhibitory effect on follicular development and ovulation, and on endometrial development and function if administered during the secretory phase of the menstrual cycle. A high dose of mifepristone, 200 mg, administered immediately following ovulation is highly effective in preventing implantation, most likely due to an effect on endometrial receptivity. It seems that the endometrium is more sensitive to antiprogestin than is the ovulatory process. Low weekly, 2.5 mg to 5 mg, and daily doses, 0.5 mg, of mifepristone did not inhibit ovulation, but a significant effect on endometrial development and especially endometrial function judged from measurement of the expression of a number of markers for endometrial receptivity could be demonstrated. CONCLUSION: The effect of mifepristone on the endometrium may be sufficient to prevent implantation, and if so, an oral contraceptive method could be developed which has no effect on ovarian function.
Contraceptives, Oral, Synthetic↗
Contraception with anti-progesterone.
Anti-progesterones have potential as contraceptives, acting either by the inhibition of ovulation or the inhibition of endometrial development. Clinical studies have shown that once-a-month treatment with Mifepristone in the early luteal phase is an effective contraceptive method, and that emergency post-coital contraception with Mifepristone is at least as effective as other methods currently used. Recent studies indicate that the endometrium is more susceptible to Mifepristone than are the hypothalamic and pituitary regions, and it may therefore be possible to develop a new contraceptive method based on low daily or once-weekly doses of Mifepristone that does not influence ovarian function.
Contraceptive Agents, Female↗
The effects of an antiprogestin, mifepristone, and an antiestrogen, tamoxifen, on endometrial 17 beta-hydroxysteroid dehydrogenase and progestin and estrogen receptors during the luteal phase of the menstrual cycle: an immunohistochemical study.
The effects of a progesterone antagonist, mifepristone (RU486), and an estrogen antagonist, tamoxifen, given during the early luteal phase on endometrial 17 beta-hydroxysteroid dehydrogenase (17HSD) and estrogen (ER) and progesterone (PR) receptors were studied. Eleven regularly menstruating women were studied during control and treatment cycles. In the treatment cycle on day LH + 2 (2 days after the peak serum LH concentration), 10 subjects received a single dose of 200 mg mifepristone, and 9 received 2 doses of 40 mg tamoxifen on days LH + 2 and LH + 3. In addition, 4 subjects received 400 mg mifepristone in a separate treatment cycle. 17HSD, ER, and PR were measured immunohistochemically in endometrial tissue specimens taken on days LH + 6 to LH + 8. Blood samples were conducted during control and treatment cycles, and serum estradiol, progesterone, and LH concentrations were quantified by RIA. Administration of mifepristone blocked the induction of 17HSD by progesterone and prevented the expression of 17HSD in gland and surface epithelial cells in 8 patients. In 2 patients, staining of 17HSD was seen during both the control and mifepristone treatment cycles. The higher dose of mifepristone additionally given to four subjects did not block the expression of 17HSD in 2 cases where blocking was observed with the lower dose of mifepristone, and in 1 of these patients, very strong staining of 17HSD was observed in basal cells beneath the epithelial cells. ER and PR showed intense staining in the nuclei of both gland and stromal cells in mifepristone treatment cycles, whereas receptor staining was faint or absent in the respective control cycles. Tamoxifen did not have any significant effect on staining of 17HSD or the abundance of receptors. Serum concentrations of estradiol, progesterone, and LH were not significantly affected by the administration of mifepristone or tamoxifen. This study reveals that mifepristone, administered in the early luteal phase, usually blocks the expression of 17HSD and the down-regulation of PR and ER. However, the expression of 17HSD in some patients may reflect the ineffectiveness of the mifepristone treatment used to prevent implantation in certain subjects.
17-Hydroxysteroid Dehydrogenases↗