Once-a-month treatment with a combination of mifepristone and the prostaglandin analogue misoprostol

Efficacy, Safety, and Acceptability of Low-Dose Mifepristone and Self-Administered Misoprostol for Ultra-Early Medical Abortion: A Randomized Controlled Trial

The aim of this study was to investigate the efficacy, safety, and acceptability of low-dose mifepristone combined with self-administered misoprostol for ultra-early medical abortion. A total of 744 women with ultra-early pregnancy (amenorrhea ≤35 days) who fulfilled the inclusion criteria were enrolled in the study. Equal numbers of participants were allocated randomly to the hospital administration and self-administration groups. All participants took 75 mg mifepristone at the initial visit and 400 µg oral misoprostol 24 hours later in the hospital or by self-administration. The primary end point was complete abortion. Secondary end points were rates of unscheduled reattendance, time required for and cost of hospital observation and follow-up, vaginal bleeding, adverse effects, menstrual disturbance in the posttreatment period, and satisfaction rating. No differences in the rates of complete abortion, unscheduled reattendance, vaginal bleeding, adverse effects, or return of posttreatment menstruation were observed. The time required for (and costs of) hospital observation and follow-up per participant was 557.82 minutes (and US$40.12) in the hospital administration group and 18.46 minutes (and US$1.96) in the self-administration group (both P < .001). Satisfaction rates were similar in both groups, but the rates of "very satisfied" responses (87.60% vs 25.41%) and follow-up compliance (loss to follow-up, 0.45% vs 7.70%) were higher in the self-administration group (both P < .001). Low-dose mifepristone combined with self-administered misoprostol for ultra-early pregnancy termination was as effective and safe as hospital administration, with greater acceptability and lower cost to the women.

Feasibility and effectiveness of unintended pregnancy prevention with low-dose mifepristone combined with misoprostol before expected menstruation

STUDY QUESTION

What is the efficacy of maintaining or restoring non-pregnant status with low-dose mifepristone combined with misoprostol administered before expected menstruation?

SUMMARY ANSWER

Low-dose mifepristone and misoprostol administered at the time of expected menstruation was effective and safe in maintaining or restoring non-pregnant status, with no obvious menstrual disturbance.

WHAT IS KNOWN ALREADY

Menstrual regulation involves the medical or mechanical stimulation of uterine sloughing in women with up to 2-3 weeks of menstrual delay. Low-dose mifepristone plus misoprostol is efficacious for termination of ultra-early pregnancy (≤ 35 days of amenorrhoea) with no obvious menstrual disturbance.

STUDY DESIGN, SIZE, DURATION

A total of 678 women fulfilled all criteria and were recruited. Seventeen women dropped out after deciding to remain pregnant and 11 others were lost to follow-up. Thus, data from 650 women who completed the procedure were included in analyses. Participants were enrolled at any time during their menstrual cycle and administered medication 1 day before expected menstruation. The end of the study was defined on a per-patient basis as the date of completion of the post-treatment menstrual cycle. The primary outcome was the efficacy of abortion induction (for pregnant women) or menstrual regulation (for non-pregnant women).

PARTICIPANTS, SETTING, METHODS

Women with regular menstrual cycles (25-35 days) were voluntarily recruited for this study between February 2012 and December 2014. Serum β-hCG was measured before mifepristone intake. Mifepristone (50 mg) was administered orally 1 day before expected menstruation and 200 µg misoprostol was administered orally on the day of expected menstruation. Efficacy, disturbance in bleeding patterns in the treatment and post-treatment cycles, satisfaction with the treatment, and subsequent contraception preference were analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

Retrospective analysis of serum β-hCG levels at admission indicated that 23.3% (158/678) of the women were pregnant. The success rate for pregnancy termination was 98.6% (136/138). Two women (1.5%, 2/138) had ongoing pregnancy that was subsequently terminated surgically. The overall bleeding induction rate within 7 days was 98.3% (639/650), with 100% (138/138) in pregnant participants and 97.9% (501/512) in non-pregnant participants. Most pregnant and non-pregnant participants experienced no significant menstrual disturbance during the treatment [96.3% (131/136) versus 97.6% (489/501)] or post-treatment [97.8% (133/136) versus 98.4% (493/501)] menstrual cycle. The general rate of satisfaction with the treatment was 96.7% (618/639). Generally, 36.0% (230/639) of participants preferred to use the regimen as a routine contraception method versus the 64.0% (409/639) who preferred to use it as a remedy for pregnancy prevention after unprotected sex (P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

Study participants were recruited from a single region; further studies should include participants from multiple centres in different cities and nations. Given the uncertain efficacy of regimen reuse, the assessment of efficacy was based solely on the first treatment administration. Studies with larger samples and long-term follow-up may provide more data on whether repeated use of this regimen hampers its efficacy.

WIDER IMPLICATIONS OF THE FINDINGS

Menstrual regulation with low-dose mifepristone and misoprostol at expected menstruation can be efficacious and highly acceptable to maintain or restore non-pregnant status, which may have potential for routine contraception.

The regulatory cliff edge between contraception and abortion: the legal and moral significance of implantation

In regulating the voluntary interruption of pregnancy, English law has accorded particular significance to two biological events. First, 'viability', the moment when a fetus is said to acquire the capacity for independent life, plays an important role in grounding restrictions on access to legal abortion later in pregnancy. Second, equally significantly but far less frequently discussed, 'implantation' marks the point in pregnancy from which abortion laws apply. This paper focuses on this earlier biological event. It suggests that an unquestioning reliance on implantation as marking an appropriate moment of transition between two radically different legal frameworks is deeply problematic and is rendered still less sustainable in the light of the development of new technologies that potentially operate shortly after the moment of implantation.

Embracing post-fertilisation methods of family planning: a call to action

Family planning methods that act when administered after fertilisation would have substantial benefits: they could be used longer after sex than current emergency contraceptives, and potentially a woman could use them only on relatively rare occasions when her menstrual period is delayed. Although such methods would displease abortion opponents, they would likely be welcomed by many women. Research to develop post-fertilisation fertility control agents should be pursued.

Termination of pregnancy at very early gestation without visible yolk sac on ultrasound

INTRODUCTION

Requests for termination of pregnancy (TOP) at very early gestation (≤6 weeks) can prove challenging for abortion services as the ultrasound feature usually accepted as definitive evidence of an intrauterine pregnancy (IUP), the presence of a yolk sac within a gestational sac, may not yet be evident. In 2011 the Edinburgh TOP service introduced a protocol permitting women to proceed to treatment without further investigations provided that ultrasound showed the features of an eccentrically placed gestational sac (≥3 mm) with a decidual reaction, and there were no signs, symptoms or risk factors for ectopic pregnancy.

METHODS

A retrospective audit was conducted of outcomes of women presenting for TOP at ≤6 weeks' gestation over a 2-year period using the hospital computerised database.

RESULTS

A total of 1155 women presented for TOP with an ultrasound gestational age of ≤6 weeks. Of these, 1030 (89%) had ultrasound evidence of a yolk sac. Eighty-seven women (7.5%) had an eccentrically placed gestational sac with a decidual reaction. All 87 women fulfilled our criteria to proceed to medical TOP, and 66 did so. In the remaining 21 cases, further investigations were performed before they proceeded to medical TOP. Two (0.17%) medical TOPs failed, both in women whose initial ultrasound had shown a yolk sac.

CONCLUSION

Women with ultrasound features consistent with a very early IUP (≥3 mm eccentrically placed gestational sac with a decidual reaction) and without signs, symptoms or risk factors for ectopic pregnancy can proceed directly to medical TOP without the need for delay for further ultrasonography.

Gynaecological uses of a new class of steroids: the selective progesterone receptor modulators

Selective progesterone receptor modulators (SPRM) represent a new class of synthetic steroids, which can interact with the progesterone receptor (PR) and can exert agonist, antagonist or mixed effects on various progesterone target tissues in vivo. This review evaluates the actual and potential usefulness of SPRMs in gynaecology.

Selective progesterone receptor modulators and progesterone antagonists: mechanisms of action and clinical applications

Since the discovery of the antiprogestin mifepristone, hundreds of similar compounds have been synthesized, which can be grouped in a large family of progesterone receptor ligands. This family includes pure agonists such as progesterone itself or progestins and, at the other end of the biological spectrum, pure progesterone receptor antagonists (PA). Selective progesterone receptor modulators (SPRM) have mixed agonist-antagonist properties, and occupy an intermediate position of the spectrum. These compounds have numerous applications in female health care. Mifepristone is used to terminate pregnancy, and as such is commercially available in many countries. The negative abortion-related image of mifepristone has clearly limited the involvement of the major pharmaceutical companies in the development of PA and SPRM. Many PA and SPRM display direct antiproliferative effects in the endometrium, although with variable actions which seem product- and dose-dependent. This property justifies their use in the treatment of myomas and endometriosis. PA also suppress late follicular development, block the LH surge and retard endometrial maturation, which renders them potential estrogen-free contraceptive drugs. SPRM such as asoprisnil are not as effective in blocking the LH surge and appear to target the endometrium directly and produce amenorrhoea. Interestingly, clinical data show that treatment with these compounds is not associated with hypo-estrogenism and bone loss. The potential clinical applications of these compounds cover a broad field and are very promising in major public health areas. These include emergency contraception, long-term estrogen-free contraception (administered alone, or in association with a progestin-only pill to improve bleeding patterns), myomas (where they induce a marked reduction in tumour volume and produce amenorrhoea) and endometriosis. Further developments might also include hormone replacement therapy in post-menopausal women, as well as the treatment of hormone-dependent tumours.

Progesterone antagonists and progesterone receptor modulators

Since the discovery of the antiprogestin RU 486 (mifepristone), other compounds have been synthesised that function as pure progesterone antagonists or progesterone receptor modulators. The latter are mixed agonists-antagonists. Mifepristone is usually used to terminate pregnancy but these compounds have numerous other applications in female healthcare. Mifepristone is an excellent agent for emergency contraception. Many progesterone antagonists and progesterone receptor modulators display antiproliferative effects on the endometrium and thus have application in the treatment of endometriosis and uterine myoma without being associated with hypoestrogenism and bone loss. They also have contraceptive potential by suppressing follicular development, blocking the luteinising hormone surge and retarding endometrial maturation. Finally, they have clinical application in GeneSwitch system, a plasmid-based method enabling controlled expression of specific genes (e.g., erythropoietin) using a progesterone antagonist as the inducer.

Mifepristone for luteal phase contraception

The concept of luteal phase contraception and the use of mifepristone in clinical trials, which allows for testing of its validity, as well as clinical pharmacological research designed to understand its mode of action, are reviewed. Early luteal phase administration has a variety of morphological, physiological and biochemical effects on the endometrium that are likely to interfere with embryonic-endometrial interactions. In fact, specifically designed pilot clinical trials as well as data derived from emergency contraception studies indicate that early luteal phase administration of mifepristone is highly effective in preventing pregnancy, with minimal disturbance of hormonal parameters or menstrual cyclicity. Mid and late luteal phase administration of mifepristone at doses above 25 mg are highly effective in inducing endometrial bleeding in nonconceptional cycles. However, administration of mifepristone within the period between implantation and expected menses fails to induce bleeding in a significant proportion of cases, and furthermore the bleeding induced does not insure the termination of pregnancy. While the data suggest there is potential for a once-a-month contraceptive pill, it is likely that no molecule endowed with partial agonistic properties, like mifepristone, will completely and reliably suppress the essential functions of progesterone in order to achieve contraceptive efficacy comparable to that of modern contraceptive methods.

Summary of evidence and research needs on the use of mifepristone in fertility regulation: consensus from the conference

The conference on the use of mifepristone to reduce unwanted pregnancy, sponsored by the World Health Organization, Concept Foundation and the Rockefeller Foundation, took place in Bellagio, Italy, between 24 and 28 September 2001. The objective of the conference was to review the scientific information and to evaluate the use of mifepristone for emergency contraception, luteal contraception and menstrual induction. Mifepristone is highly effective for emergency contraception but its advantages and disadvantages in comparison with levonorgestrel need to be further studied. Data indicate that mifepristone alone or in combination with misoprostol has potential for occasional use for women seeking help following repeated unprotected intercourse and/or when the interval between intercourse and treatment is more then 120 h. Administration of mifepristone immediately after ovulation seems to be an effective contraceptive method. However, before it can be used commonly, there is a need for a simple and inexpensive method to identify the right time in the cycle. Once-a-month treatment with mifepristone and misoprostol at the expected time of menstruation is not a practical method due to bleeding irregularities and timing of treatment. Menstrual induction with mifepristone and a suitable prostaglandin analogue is highly effective. A randomized comparison with manual vacuum aspiration is, however, needed before it can be recommended for routine use.

Luteal phase treatment with mifepristone and misoprostol for fertility regulation

Emergency contraception (EC) with 10 mg mifepristone can prevent pregnancy up to 5 days after a single act of unprotected intercourse. No methods have been shown to be effective when treatment is administered more than 5 days after a single unprotected act or after several unprotected acts. Therefore, we tested, among 699 Chinese women requesting EC and exposed to the risk of pregnancy described, the potential of 100 mg mifepristone followed 2 days later by 0.4 mg misoprostol orally, when administered in the luteal phase of the cycle. At the time of treatment urinary pregnancy test had to be negative. Despite treatment, 25 women (2.7%) became pregnant. Among women with treatment delayed more than 5 days, the pregnancy rate was related to the number of acts of intercourse before treatment, being 1.4% with one episode and increasing to 6.5% when the number of episodes was two or more (relative risk = 4.62, 95% CI: 1.06-20.18). Side effects within a week after treatment were mild, and most women (57.2%) had menstruation within 3 days as expected. An occasional treatment with mifepristone in combination with misoprostol could provide an option for preventing unwanted pregnancies in women who are late for EC.

Mechanisms of action of mifepristone when used for emergency contraception

An emergency contraceptive method is used after coitus but before pregnancy occurs. The use of emergency contraception is largely underutilized worldwide. Recently, treatment with 10 mg mifepristone as a single dose has emerged as one of the most effective hormonal methods for emergency contraception, with very low side effects. However, the mechanism of action of mifepristone in humans when used for contraceptive purposes and especially for emergency contraception remains largely unknown. The objective of this review is to summarize available data on the effect of mifepristone on female reproductive functions relevant to emergency use of the compound. Taken together, available data from studies in humans indicate that the contraceptive effect of mifepristone used as a single low dose for emergency contraception is mainly due to impairment of ovarian function, either by blocking or postponing the luteinizing hormone surge, rather than to inhibiting of implantation.

A single dose of mifepristone (200 mg) in the immediate preovulatory phase offers contraceptive potential without cycle disruption

A single dose of mifepristone is an effective emergency contraceptive and has potential as a regular "once-a-month" pill. If given in the early luteal phase, the formation of a secretory endometrium is inhibited or delayed and implantation of the embryo prevented. We have explored the effect of giving the mifepristone just prior to ovulation on the ovarian and endometrial cycle. Seven women with regular menstrual cycles were studied during a control cycle and then in a second cycle when 200 mg mifepristone was given within 24 h of ovulation, i.e., when luteinizing hormone (LH) in serum was >15 IU/L and the dominant follicle was >18 mm. Ovulation was confirmed within 48 h by ultrasound in five of the seven women. The remaining two women had luteinized unruptured follicle. Following mifepristone, menses occurred after a normal luteal phase compared to control cycle (13.7 +/- 0.7 vs. 13.7 +/- 0.9 days). In all subjects the endometrium on LH + 6 in the treatment cycle showed no, or very little, secretory changes, suggesting it was unlikely that pregnancy would have occurred. We conclude that mifepristone could be given as a "once-a-month" contraceptive pill without causing significant disruption in the menstrual cycle in the majority of women for a 4-day period from just prior to ovulation until LH + 3.

Effect of mifepristone on pregnancy, pregnancy-specific protein B (PSPB), progesterone, estradiol-17beta, prostaglandin F2alpha (PGF2alpha) and prostaglandin E (PGE) in ovariectomized 90-day pregnant ewes

The objective of this experiment was to determine the effect of mifepristone, a progesterone receptor antagonist, on pregnancy and secretion of steroids, pregnancy-specific protein B (PSPB) and prostaglandins at mid-pregnancy in ewes. Ninety-day pregnant ewes were ovariectomized (OVX) and treatments were initiated 72 h post-OVX. Ewes received (1) vehicle, (2) prostaglandin F2alpha (PGF2alpha, 8 mg/58 kg/bw, i.m.) 84 h post-OVX, (3) mifepristone (50 mg intrajugular at 72, 84, 96, and 108 h post-OVX), (4) mifepristone (50mg) + PGF2alpha, (5) mifepristone (100 mg intrajugular at 72, 84, 96, and 108 h), and (6) mifepristone (100 mg) + PGF2alpha. Ewes treated with vehicle or PGF2alpha alone did not abort (P > or = 0.05). But, 60, 80, 60, and 100% of ewes treated with mifepristone (50 mg), mifepristone (50 mg) + PGF2alpha, mifepristone (100 mg), and mifepristone (100 mg) + PGF2alpha, respectively, aborted (P < or = 0.05). Profiles of progesterone, estradiol-17beta, prostaglandin E (PGE), or PSPB did not differ (P > or = 0.05) among treatment groups. Profiles of PGF2alpha of treatment groups receiving mifepristone with or without PGF2alpha differed (P < 0.05) from vehicle or PGF2alpha alone-treated ewes. It is concluded that progesterone actions are necessary to suppress uterine/placental secretion of PGF2alpha and that maintenance of critical progesterone: estradiol-17beta and PGE:PGF2alpha ratios are necessary for maintenance of pregnancy.

Mifepristone: contraceptive and non-contraceptive uses

Mifepristone is an orally active progesterone antagonist. It can be used for both contraceptive and non-contraceptive clinical indications. It is a very effective drug for emergency contraception with a low incidence of side effects. There is a potential for mifepristone to be used as a once-a-month pill. There is a need, however, for a simple, inexpensive and accurate method to identify the luteinizing hormone surge before this method can be used in clinical practice. The daily administration of mifepristone offers promise as an effective method of contraception but more studies need to be done. The combination of mifepristone with a prostaglandin analogue is a well-established method for termination of pregnancy of up to 9 weeks. Recent data suggest that this combination may also be used up to 9-13 weeks of pregnancy. Although mifepristone is effective in dilating the cervix before vacuum aspiration, misoprostol is probably the drug of choice in most situations. In the second trimester, mifepristone is effective in shortening the abortion process induced by prostaglandin analogues. The combination of mifepristone and prostaglandin also offers a medical method for management of miscarriages. Mifepristone has been used for a number of other indications, but further studies are needed before such treatment can be recommended.