The development of ovarian tissue cryopreservation in Edinburgh: Translation from a rodent model through validation in a large mammal and then into clinical practice.

Ovarian tissue cryopreservation has developed rapidly from its origins in experiments in sheep in the 1990s, and is now becoming recognized as a standard, rather than experimental, procedure. This review summarizes the origins of the technique, and key milestones in its development since the first reported sheep pregnancy in 1994 to the first successful human pregnancy in 2004, and now to the first baby born following cryopreservation of prepubertal ovarian tissue. Many challenges remain to optimize this technique, to improve the survival of follicles within the reimplanted ovarian tissue, to improve its reproducibility and hence the success rate and the lifespan of the graft. The other key area remains the possibility of the grafted tissue containing malignant cells, most importantly in leukemia.

Can midlevel health-care providers administer early medical abortion as safely and effectively as doctors? A randomised controlled equivalence trial in Nepal.

BACKGROUND: Medical abortion is under-used in developing countries. We assessed whether early fi rst-trimester medical abortion provided by midlevel providers (government-trained, certified nurses and auxiliary nurse midwives) was as safe and effective as that provided by doctors in Nepal. METHODS: This multicentre randomised controlled equivalence trial was done in fi ve rural district hospitals in Nepal. Women were eligible for medical abortion if their pregnancy was of less than 9 weeks (63 days) and if they resided less than 90 min journey away from the study clinic. Women were ineligible if they had any contraindication to medical abortion. We used a computer-generated randomisation scheme stratified by study centre with a block size of six. Women were randomly assigned to a doctor or a midlevel provider for oral administration of 200 mg mifepristone followed by 800 µg misoprostol vaginally 2 days later, and followed up 10-4 days later. The primary endpoint was complete abortion without manual vacuum aspiration within 30 days of treatment. The study was not masked. Abortions were recorded as complete, incomplete, or failed (continuing pregnancy). Analyses for primary and secondary endpoints were by intention to treat, supplemented by per-protocol analysis of the primary endpoint. This trial is registered with ClinicalTrials.gov, NCT01186302. FINDINGS: Of 1295 women screened, 535 were randomly assigned to a doctor and 542 to a midlevel provider. 514 and 518, respectively, were included in the analyses of the primary endpoint. Abortions were judged complete in 504 (97.3%) women assigned to midlevel providers and in 494 (96.1%) assigned to physicians. The risk difference for complete abortion was 1.24% (95% CI -0.53 to 3.02), which falls within the predefined equivalence range (-5% to 5%). Five cases (1%) were recorded as failed abortion in the doctor cohort and none in the midlevel provider cohort; the remaining cases were recorded as incomplete abortions. No serious complications were noted. INTERPRETATION: The provision of medical abortion up to 9 weeks' gestation by midlevel providers and doctors was similar in safety and effectiveness. Where permitted by law, appropriately trained midlevel health-care providers can provide safe, low-technology medical abortion services for women independently from doctors. FUNDING: UNDP/UNFPA/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research (RHR), World Health Organization.

Emergency contraception: how does it work?

Emergency (or post-coital) contraception is any substance or device that is used to prevent pregnancy after unprotected intercourse. Currently used hormonal methods of emergency contraception (high-dose combined oral contraceptive pill or levonorgestrel) prevent about 50-80% of pregnancies. Research has demonstrated that these methods inhibit the midcycle surge of LH from the pituitary and, if given at least 2 days before ovulation, ovulation is delayed or prevented. Ovulation still occurs if administration is delayed until ovulation is imminent. Biological data that suggest that the most likely mode of action is by preventing fertilization are supported by the clinical observation that the greater the interval between coitus and administration the greater the chance of pregnancy. There are no data supporting the view that levonorgestrel can impair the development of the embryo or prevent implantation. In contrast, other very effective methods of emergency contraception, such as mifepristone and intrauterine devices, can also inhibit implantation.

7alpha-methyl-19-nortestosterone (MENT) vs testosterone in combination with etonogestrel implants for spermatogenic suppression in healthy men.

Testosterone with a progestogen can suppress spermatogenesis for contraception. The synthetic androgen 7alpha-methyl-19-nortestosterone (MENT) may offer advantages because it is resistant to 5alpha-reduction and is therefore less active at the prostate. This study aimed to investigate MENT implants in combination with etonogestrel on spermatogenesis, gonadotropins, and androgen-dependent tissues in comparison with a testosterone/etonogestrel regimen. Healthy men (n = 29) were recruited and randomized to receive 2 etonogestrel implants with either 600-mg testosterone pellets repeated every 12 weeks or 2 MENT implants for up to 48 weeks. Testosterone concentrations in the testosterone group remained in the normal range. Subjects with 2 MENT implants showed peak MENT levels at 4 weeks with testosterone concentrations of 2 nmol/L. Sperm concentrations fell rapidly to less than 1 x 10(6)/mL at 12 weeks in 8 of 10 subjects in the MENT group and 13 of 16 subjects in the testosterone group with equally suppressed gonadotropins. Thereafter, suppression was not maintained in the MENT group, and 6 men noted loss of libido. Fourteen men completed 48 weeks of testosterone treatment, and all became azoospermic. Hemoglobin concentrations rose, and high density lipoprotein-cholesterol (HDL-C) fell in both groups. The MENT group showed a fall in prostate-specific antigen with no change in bone mass. MENT with a progestogen can achieve rapid suppression of spermatogenesis similar to testosterone, but this promising result was not sustained due to a decline in MENT release from the implants. This dose of testosterone, compared with previous studies using a lower dose with a higher dose of etonogestrel, had nonreproductive side effects without any increase in spermatogenic suppression. These data indicate the importance of the doses of progestogen and testosterone for optimum spermatogenic suppression while minimizing side effects.

Changes in vaginal morphology, steroid receptor and natural antimicrobial content following treatment with low-dose mifepristone.

BACKGROUND: We have previously shown that the antigestagen mifepristone is contraceptive when given in a daily dose of 5 mg, po. Epidemiological studies suggest that gestagen-only contraceptives may increase the risk of transmission of human immunodeficiency virus (HIV) due to effects on the vaginal defenses to infection. We investigate the effects of mifepristone on vaginal thickness, steroid receptor and natural antimicrobial content and pharmacokinetics of mifepristone. METHODS: In a pilot study, eight women were given mifepristone 5 mg/day for an average of 33 days. Ovarian function was assessed by measurement of estradiol and progesterone in blood and their metabolites in urine and by serial ultrasound of their ovaries. Vaginal biopsies were collected before (late proliferative) and after taking mifepristone. RESULTS: All subjects showed a similar pattern of descending serum concentrations of mifepristone. The elimination phase half-life was 18+/-5.1 h (mean+/-SD). Mean Cmax measured at 1 h was 641.7 nmol/L (range, 502-740 nmol/L). All eight women reported amenorrhea for the duration of treatment and seven of eight women showed biochemical and ultrasound evidence of anovulation. There was no significant change in vaginal thickness following treatment [342+/-40 microm pretreatment, 303+/-69 microm posttreatment (mean+/-SEM); p>.05]. Estrogen (ERalpha, ERbeta) and androgen receptor were expressed in both vaginal epithelium and subepithelial stroma, whereas progesterone receptor was expressed predominantly in the subepithelial stroma. There was no change in receptor content and distribution following mifepristone treatment. Natural antimicrobial mRNA [secretory leukocyte protease inhibitor, human beta defensins mRNA (HBD1, HBD2, HBD3, HBD5), granulysin and elafin] was extracted from the vaginal tissues, and the content was unaffected by mifepristone treatment. CONCLUSION: The absence of changes in vaginal thickness, steroid receptor and natural antimicrobial content and its distribution in this preliminary study suggests that in contrast to other estrogen-free contraceptives, mifepristone is unlikely to be associated with the increased risk of transmission of HIV and other sexually transmitted infections.

Direct effect of progestogen on gene expression in the testis during gonadotropin withdrawal and early suppression of spermatogenesis.

CONTEXT: Testicular production of steroids and gametes is under gonadotropin support, but there is little information as to the molecular mechanisms by which these are regulated in the human. The testicular response to gonadotropin withdrawal is important for the development of effective contraceptive methods. OBJECTIVE: Our objective was investigation of expression of genes in the normal human testis reflecting steroidogenesis, Sertoli cell function, and spermatogenesis after short-term gonadotropin withdrawal and the effects of activating testicular progesterone receptors. DESIGN AND SETTING: We conducted a randomized controlled trial at a research institute. PATIENTS: Thirty healthy men participated. INTERVENTIONS: Subjects were randomized to no treatment or gonadotropin suppression by GnRH antagonist (cetrorelix) with testosterone (CT group) or with additional administration of the gestogen desogestrel (CTD group) for 4 wk before testicular biopsy. Gene expression was quantified by RT-PCR. RESULTS: Both treatment groups showed similar suppression of gonadotropins and sperm production and markedly reduced expression of steroidogenic enzymes. Addition of progestogen in the CTD group resulted in reduced expression of 5alpha-reductase type 1 compared with both controls and the CT group. Inhibin-alpha and the spermatocyte marker acrosin-binding protein were significantly lower in the CTD but not CT groups, compared with controls, but did not differ between treated groups. Men who showed greater falls in sperm production also showed reduced expression of these three genes but not of the spermatid marker protamine 1. CONCLUSIONS: These data provide evidence for direct progestogenic effects on the testis and highlight steroid 5alpha-reduction and disruption of spermiation as important components of the testicular response to gonadotropin withdrawal.

Regulation of human endometrial function: mechanisms relevant to uterine bleeding.

This review focuses on the complex events that occur in the endometrium after progesterone is withdrawn (or blocked) and menstrual bleeding ensues. A detailed understanding of these local mechanisms will enhance our knowledge of disturbed endometrial/uterine function--including problems with excessively heavy menstrual bleeding, endometriosis and breakthrough bleeding with progestin only contraception. The development of novel strategies to manage these clinically significant problems depends on such new understanding as does the development of new contraceptives which avoid the endometrial side effect of breakthrough bleeding.

Comparison of a transdermal continuous combined and an interrupted progestogen HRT.

OBJECTIVES: Pilot study to compare the effects of a continuous combined hormone replacement therapy (HRT) regimen with an interrupted progestogen regimen administered transdermally, upon the endometrium of postmenopausal women, the incidence of amenorrhoea and relief of menopausal symptoms. METHODS: Fifty-nine postmenopausal women aged 50-63 years were randomised to either (i) continuous combined regimen: combined oestrogen/progestogen skin patches (releasing continuous 50 microg estradiol and 20 microg levonorgestrel/day) or (ii) interrupted regimen: oestrogen-only patches (releasing 80 microg estradiol/day) for 4 days followed by combined oestrogen/progestogen patches (releasing continuous 50 microg estradiol and 20 microg levonorgestrel/day) for 3 days, for 6 months. An endometrial biopsy was performed at end of treatment for histological analysis. RESULTS: Thirty-three women (56%) completed the study. Significantly higher rates of amenorrhoea were observed with the interrupted than continuous combined regimen (P<0.0001; 25% versus 7% at 6 months). The interrupted regimen was also associated with fewer days of bleeding overall (total 20 versus 44 days during months 4-6; P=0.001). Both regimens improved vasomotor symptoms. No endometrial hyperplasia or atypical changes were observed in endometrial biopsies. CONCLUSIONS: Although significantly less bleeding was observed with the interrupted regimen, it did not have a sufficiently high incidence of amenorrhoea to render it clinically useful.

Leukocyte populations and steroid receptor expression in human first-trimester decidua; regulation by antiprogestin and prostaglandin E analog.

CONTEXT: Progesterone acting via its cognate receptor is critical to maintaining a viable endometrial environment for implantation and pregnancy. During medical termination of pregnancy, the biological effect of progesterone is pharmacologically withdrawn and prostaglandins administered exogenously. Leukocytes within the uterus are the effector cells of an inflammatory response and play important roles in both tissue breakdown and remodeling. OBJECTIVE: The aim of this study was to identify the separate and combined effects of the antiprogestin Mifepristone (single dose, 200 mg) and the prostaglandin E (PGE) analog (gemeprost) on leukocyte populations and steroid receptor expression in human first-trimester decidua. PATIENTS: Eighty women were recruited from the termination of pregnancy service with a gestational age of between 35 and 65 d at the time of surgical termination of pregnancy. MAIN OUTCOME MEASURES: Immunohistochemistry was used to measure macrophage (CD68 +ve), neutrophil (neutrophil elastase +ve), and uterine natural killer cell (CD56 +ve) populations and progesterone (PR(A) and PR(B)), estrogen (ERalpha and ERbeta), and androgen receptor (AR) expression. RESULTS: After administration of both antiprogestin and the PGE analog, macrophage and neutrophil numbers were significantly increased, whereas natural killer cell numbers were unchanged. Antiprogestin and PGE analog coadministration also significantly decreased PR and ERalpha immunoreactivity but had no effect on androgen receptor or ERbeta receptor expression. PGE analog alone was also capable of reducing PR expression. CONCLUSIONS: In this study, we demonstrate that the inflammatory response induced by antiprogestin in combination with PGE analog is accompanied by both increases in macrophages and neutrophils numbers and decreases in PR and ERalpha expression in human first-trimester decidua.

Evidence of a role for follicle-stimulating hormone in controlling the rate of preantral follicle development in sheep.

Autografting ovarian cortex results in the loss of growing follicles and elevated gonadotropins. This paradigm was employed to examine the effect of gonadotropins on preantral follicle development in sheep. Ovarian tissue was recovered at 1, 2, 3, and 4 months after grafting from ewes that were either hyper- (n = 12; untreated) or hypogonadotropic (n = 12; GnRH-agonist and estradiol implants). Compared with the Hypo group, Hyper ewes had higher (P < 0.001) gonadotropins, had greatly enlarged grafts, had reestablished a normal follicular hierarchy 2 months earlier (P < 0.05), had higher (P < 0.05) levels of proliferating cell nuclear antigen expression in tertiary, preantral, and antral follicles, and had higher (P < 0.01) concentrations of inhibin A and estradiol. Compared with time zero controls, increases in the number of primary follicles and the rate of proliferation in primary and secondary follicles in both groups of autografts (P < 0.05) were also observed. In conclusion, the results of this experiment provide the first evidence that gonadotropins can affect the rate of development of preantral follicles in vivo in a large monovulatory species. Furthermore data are presented to support the existence of a gonadotropin-independent intraovarian feedback loop regulating both the rate of primordial follicle initiation and primary and secondary follicle development.

Effect of ageing on hormone secretion and follicular dynamics in sheep with and without the Booroola gene.

It has been suggested that ewes carrying the Booroola gene (Fec(B)) consistently ovulate more follicles because they recruit more primordial follicles and/or have a lower rate of atresia. If the former is correct, the pool of follicles would be depleted sooner in Fec(B) animals. We have studied follicular dynamics and endocrine function during follicular and early luteal phases of the estrous cycle of older ewes with or without the fecundity gene and compared this data with data obtained 6 yr previously in the same animals. Older sheep carrying the Booroola gene maintained a significantly higher ovulation rate than noncarrier ewes [4.2 +/- 0.8 vs. 2.2 +/- 0.6 corpora lutea (CL), respectively; P < 0.05], and in keeping with data from young animals, both ovulatory follicles and CL (4.7 +/- 0.3 vs. 6.9 +/- 0.7 mm and 12.8 +/- 0.5 vs. 16.7 +/- 0.8 mm, respectively) were smaller than those of noncarrier ewes (P < 0.05). The interval from luteolysis to the onset of the LH surge increased with age in all the animals (from 52.0 +/- 8.0 to 67.0 +/- 7.5 h in gene carrier sheep and from 56.0 +/- 2.0 to 79.5 +/- 9.6 h in noncarrier sheep, P < 0.05). The concentration of estradiol and inhibin A in the early luteal phase was lower in older noncarrier ewes (P = 0.08 and P < 0.05, respectively), and the level of inhibin A was inversely related to the level of FSH in aged sheep of both genotypes (P < 0.0001). In contrast, the number of developing follicles in older ewes of both genotypes was similar to the number found in younger ewes, suggesting that increased ovulation rate in sheep carrying the Fec(B) mutation is related to a reduced rate of atresia.

Daily low-dose mifepristone has contraceptive potential by suppressing ovulation and menstruation: a double-blind randomized control trial of 2 and 5 mg per day for 120 days.

Daily administration of progesterone (P) antagonists to women inhibits ovulation and disrupts endometrial function. In this double-blind randomized trial, we have explored the contraceptive potential of two doses of the P antagonist mifepristone in healthy volunteers in Edinburgh and Shanghai. Ninety-eight women (58 in Edinburgh and 40 in Shanghai) were randomized to receive either 2 or 5 mg mifepristone daily for 120 d. Ovarian activity was monitored by the weekly measurement of steroid metabolites in urine and of E2 and P in plasma every month. Endometrial function was assessed by menstrual records, and ultrasound measurement of endometrial thickness was assessed every month. Endometrial biopsy was collected on d 12 of the control cycle and after 60 and 120 d of treatment. Ninety women (50 in Edinburgh and 40 in Shanghai) completed the study. Follicular activity continued during treatment with both doses in Edinburgh women, although ovulation was suppressed in the majority of cycles (90 and 95% of cycles in 2- and 5-mg groups, respectively). The women in Shanghai showed evidence of ovulation in only 3 of 160 months of treatment (2 in 2-mg group and 1 in 5-mg group). The majority of women in both centers were amenorrheic (65% in 2-mg group and 88% in 5-mg group in Edinburgh, and 90% in both dose groups in Shanghai). The endometrial thickness increased significantly in women in Edinburgh and decreased in Shanghai; histology showed either atrophic or cystic changes without evidence of hyperplasia. There was no pregnancy reported in the 200 months of exposure in 50 sexually active women who had used no other method of contraception during the study. We conclude that mifepristone in low daily doses inhibits ovulation and induces amenorrhea in the majority of women and has the potential to be developed as a novel estrogen- free oral contraceptive pill.

Low-dose mifepristone inhibits endometrial proliferation and up-regulates androgen receptor.

Mifepristone in daily low doses has contraceptive potential by inhibiting ovulation. Follicular development is maintained, and although the endometrium is exposed to unopposed estrogen, there are no signs of hyperplasia or atypia. The mechanism of this antiestrogenic action is unknown. We have investigated the effect of daily low-dose mifepristone on proliferation markers and steroid receptors in surface epithelium, glands, and stroma of the endometrium. Endometrial biopsies were collected from 16 women before (late proliferative) and 60 and 120 d after taking 2 or 5 mg mifepristone daily for 120 d. Endometrial proliferation (H3 mitosis marker) and steroid (estrogen, progesterone, and androgen) receptor content were studied using standard immunocyotchemistry techniques. There was a significant decrease in the expression of H3 mitosis marker (P

Mifepristone-induced vaginal bleeding is associated with increased immunostaining for cyclooxygenase-2 and decrease in prostaglandin dehydrogenase in luteal phase endometrium.

The mechanism of mifepristone-induced vaginal bleeding and endometrial shedding was investigated in 13 women who took 200 mg mifepristone in the midluteal phase on d 8 after the onset of the urinary LH surge (LH+8). Endometrial biopsies were collected, 6-24 h after mifepristone (group 1, n = 7) or 36-48 h after mifepristone (group 2, n = 6), and compared with those from a control group in the midluteal phase (n = 7). All women reported vaginal bleeding commencing 36-48 h after taking mifepristone. Treatment with mifepristone significantly reduced serum progesterone levels in all women, when compared with the controls (13.2 nM vs. 34.8 nM, P = 0.001). After mifepristone, a significant increase in cyclooxygenase-2 immunoreactivity was apparent at 36-48 h (P = 0.0018), whereas prostaglandin 15 dehydrogenase enzyme-positive immunostaining declined, to be virtually absent by 36-48 h in both glands and in stroma (P < 0.05). There was no change in intensity or distribution of staining for steroid receptors after mifepristone. The changes in immunostaining for cyclooxygenase-2 and prostaglandin 15 dehydrogenase strongly support the hypothesis that an increase in the local concentration of prostaglandins in the endometrium is involved in the mechanism of bleeding induced by mifepristone in the luteal phase.

A prospective randomized clinical trial comparing 150 IU and 225 IU of recombinant follicle-stimulating hormone (Gonal-F*) in a fixed-dose regimen for controlled ovarian stimulation in in vitro fertilization treatment.

OBJECTIVE: To compare fixed daily doses of the recombinant FSH (rFSH) Gonal-F (150 IU vs. 225 IU) for ovarian stimulation in IVF-ET. DESIGN: Single-center prospective, randomized study. Assisted conception unit of a university hospital. One hundred twenty-four women aged 23-41 years participated in the study. Exclusion criteria were as follows: FSH of >10 IU/L, polycystic ovarian syndrome, one ovary or previous ovarian surgery, previous poor response to ovarian stimulation, or ovarian hyperstimulation syndrome (OHSS). INTERVENTION(S): Randomized to commence 150 IU or 225 IU of Gonal-F per day without dose alterations during treatment. MAIN OUTCOME MEASURE(S): Number of oocytes retrieved and total rFSH dose. RESULT(S): More oocytes were retrieved in women aged or=33 years), the number of oocytes retrieved in the two groups were similar. No significant differences were found for fertilization rate, number of embryos formed and cryopreserved, and pregnancy rates between the two groups. The total rFSH dose used was higher in the 225-IU group (2,595.0 +/- 510.0 vs. 1,897.5 +/- 457.5 IU). The cancellation rate due to insufficient ovarian response was higher in the 150-IU group (15.0% vs. 3.3%). All cases of ovarian hyperstimulation syndrome (n = 4) occurred in the 225-IU group. CONCLUSION(S): Two hundred twenty-five IU is more effective than 150 IU in younger women but requires a higher total dose of Gonal-F. The use of 225 IU in older women did not result in a higher oocyte yield, suggesting that 225 IU of rFSH does not compensate for the age-related decline in the number of follicles available for stimulation.

A role for the androgen receptor in the endometrial antiproliferative effects of progesterone antagonists.

In women and nonhuman primates, treatment with progesterone antagonists suppresses estrogen-dependent mitotic activity in the endometrial glands. This antiproliferative effect is paradoxical, because progesterone antagonists do not bind to the estrogen receptor (ER). While this phenomenon has been termed a "functional noncompetitive antiestrogenic effect," it does not occur in all species or in all regions of the primate reproductive tract, so is best referred to as an "endometrial antiproliferative effect." Recent studies of ours in both women and macaques revealed that the endometrial androgen receptor (AR) was increased by progesterone antagonist treatment. Because androgens are known to suppress estrogen-dependent endometrial proliferation, we hypothesized that the AR was involved in the antiproliferative effects induced by progesterone antagonists. In a test of this hypothesis, we administered the antiandrogen, flutamide, along with progesterone antagonists to ovariectomized, estrogen-treated macaques. Flutamide counteracted the suppressive effects of the progesterone antagonists on endometrial wet weight, thickness, stromal compaction, and mitotic index. Hyaline degeneration of the spiral arteries was also blocked by flutamide. These data implicate the AR as a functional component of the mechanism through which progesterone antagonists induce endometrial antiproliferative effects in the presence of estrogens.

Antiprogestins as a model for progesterone withdrawal.

The key physiological function of the endometrium is preparation for implantation; and in the absence of pregnancy, menstruation and repair. The withdrawal of progesterone is the initiating factor for breakdown of the endometrium. The modulation of sex steroid expression and function with pharmacological agents has provided an invaluable tool for studying the functional responses of the endometrium to sex steroids and their withdrawal. By administration of the antiprogestin mifepristone, it is possible to mimic progesterone withdrawal and study local events in early pregnancy decidua that may play a role in the process of early pregnancy failure. Our data indicate that antagonism of progesterone action at the receptor level results in an up-regulation of key local inflammatory mediators, including NF-kappaB, interleukin-8 (IL-8), monocyte chemotactic peptide-1 (MCP-1), cyclooxygenase 2 (COX-2) and others in decidua. Bleeding induced by mifepristone in the mid-luteal phase of the cycle is associated with changes in the endometrium similar to those that precede spontaneous menstruation including up-regulation of COX-2 and down-regulation of PGDH. Administration of antagonists of progesterone provide an excellent model to study the mechanisms involved in spontaneous and induced abortion as well as providing information which may help devise strategies for treating breakthrough bleeding associated with hormonal contraception.

Effects of onapristone on postmenopausal endometrium.

The progesterone antagonist mifepristone (RU486, Exelgyn) has been shown to exert a paradoxical agonist effect on postmenopausal endometrium. We conducted a study to investigate the effects of the 'pure' antiprogestin onapristone (ZK 98 299, Schering AG) on postmenopausal endometrium. Seventeen postmenopausal subjects (45-62 years), took 2 mg of oestradiol and either placebo, 1 mg onapristone or 10 mg of onapristone, daily for 56 days. An endometrial biopsy was performed during the final week of treatment and assessed for histology and immunohistochemistry for oestrogen receptors (ER), progesterone (PR), androgen receptors (AR) and the cell proliferation marker Ki 67. FSH fell in all 14 subjects who completed the study, consistent with the effect of oestradiol treatment. There was a dose-dependent additive effect of onapristone on suppression of gonadotrophins. All endometrial biopsies showed proliferative endometrium. A similar pattern and intensity of immunostaining of ER, PR and Ki 67 was observed in all groups, with positive immunoreactivity in both glands and stroma. AR immunostaining was observed in both glands and stroma from all subjects, but there was an increase in intensity of immunostaining within the glandular epithelium of women receiving 10 mg onapristone. The antiprogestin onapristone, in contrast to mifepristone, is not agonistic on postmenopausal endometrium and does not exert obvious antiproliferative effects. It does however cause a dose dependent suppression of FSH and LH release.

Mifepristone: a novel estrogen-free daily contraceptive pill.

When the first synthetic progesterone antagonist (mifepristone) was synthesized over 20 years ago, it was clear that it had a potential as an antifertility agent. Research into the use of antiprogestogens for contraception have concentrated on three general approaches: (1) inhibition of ovulation, (2) inhibition of implantation and (3) disruption of implantation or "menstrual induction". The effect of mifepristone on the ovarian and endometrial cycle depends on dose, timing and frequency of administration. Doses of 10 mg per day or more suppress follicular development and estradiol levels. Ovulatory cycles are maintained in the dose of less than 2 mg although there is increased variability in cycle length. The endometrium shows some minor asynchronous changes, although these are not sufficient to prevent pregnancy. We have chosen to investigate daily doses between 2 and 5 mg which inhibit ovulation and menstruation in over 90% of cycles while still maintaining follicular development and levels of estradiol within the range found during the follicular phase. The endometrium shows proliferative or cystic changes lined by a layer of inactive glandular epithelium set in densely packed stroma. There is, however, an absence of proliferative activity as reflected by a reduced mitotic index and Ki67 staining. These unusual histological appearances are associated with downregulation of PR but a massive upregulation of AR in particularly glandular epithelium. The antiproliferative effect of mifepristone is reassuring suggesting that the risk of atypical hyperplasia due to the effect of prolonged exposure to estrogen unopposed by progesterone is low. In a pilot study, there were no pregnancies in 200 months of exposure in 50 women who used this method as their sole method of contraception. Daily mifepristone could provide a novel contraceptive method which should be devoid of the risks associated with estrogen containing combined oral contraceptive (COC), e.g. venous thromboembolism. The health benefits of avoiding the morbidity associated with menstruation are considerable. Recent surveys suggest that amenorrhoea would be popular with many women.

Medical abortion in the first trimester.

Pregnancy can be terminated safely by inducing abortion medically at any stage of gestation. Antagonists such as mifepristone block the action of progesterone and hence result in uterine contractions and increase the sensitivity of the uterus to prostaglandins. In the last 15 years the combination of a single dose of mifepristone (600 mg) followed 48 hours later with a suitable prostaglandin (1 mg gemeprost vaginal pessary or 400 microg oral misoprostol) has been licensed in most countries in Europe and the USA for induction of abortion in the early weeks of pregnancy. The safety and efficacy of these methods is comparable to vacuum aspiration at the same gestation. The complete abortion rate is related to the type and dose of prostaglandin, the route of administration as well as the gestation and parity. Published data suggest that the dose of mifepristone can be reduced from 600 mg to 200 mg without loss of efficacy. Although misoprostol tablets are formulated for oral use, extensive clinical experience has demonstrated vaginal administration is more effective and is associated with fewer side-effects. Successful abortion using medical methods requires a well organized service which includes referral without delay and a robust system of follow up to identify failures. The failure rate as reflected by the number of women who require surgical intervention falls with increasing experience. In those countries where medical abortion has been freely available for about 10 years, such as France, Scotland and Sweden, about 60-70% of eligible women elect for this method.