Effectiveness and Safety of Lower Doses of Mifepristone Combined With Misoprostol for the Termination of Ultra-Early Pregnancy: A Dose-Ranging Randomized Controlled Trial

Combination of Mifepristone and Misoprostol for First-Trimester Medical Abortion: A Comprehensive Review of the Literature

Importance

Several medications have been used to achieve medical abortion in the first trimester of pregnancy. The most commonly used is the combination of mifepristone and misoprostol; however, different doses and routes of administration have been proposed.

Objective

The aim of this study was to summarize published data on the effectiveness, adverse effects, and acceptability of the various combinations of mifepristone and misoprostol in medical abortion protocols in the first trimester of pregnancy.

Evidence Acquisition

This was a comprehensive review, synthesizing the findings of the literature on the current use of mifepristone and misoprostol for first-trimester abortion.

Results

The combination of mifepristone and misoprostol seems to be more effective than misoprostol alone. Regarding the dosages and routes, mifepristone is administered orally, and the optimal dose is 200 mg. The route of administration of misoprostol varies; the sublingual and buccal routes are more effective; however, the vaginal route (800 μg) is associated with fewer adverse effects. Finally, the acceptability rates did not differ significantly.

Conclusions

Different schemes for first-trimester medical abortion have been described so far. Future research needs to focus on identifying the method that offers the best trade-off between efficacy and safety in first-trimester medical abortion.

Medical Abortion before Confirmed Intrauterine Pregnancy: A Systematic Review

"Very early medical abortion" (VEMA) refers to medical abortion (with mifepristone and misoprostol) before intrauterine pregnancy is visualized on ultrasound. Our aim is to present the current evidence on efficacy, safety (focused on ectopic pregnancies), and how to assess treatment success of VEMA. We conducted a systematic review of studies reporting outcomes of VEMA. The field is small and so our objective was to map all relevant literature, without conducting meta-analysis. We searched PubMed, Medline, and Embase on April 19, 2022. We conducted a narrative synthesis of the evidence. A total of 373 articles were identified. Six articles (representing four observational and one pilot trial) were included in the final review. Across all included studies, treatment efficacy ranged between 91 and 100%. Prevalence of ectopic pregnancy was low and very few cases (n = 2) of ruptures were reported. Most studies used serial serum human chorionic gonadotrophin (s-hCG) levels to determine success of abortion; one study used low sensitivity urine hCG. From the available evidence, VEMA appears to be efficacious and does not appear to cause harm to ectopic pregnancies. Treatment can be assessed with pre- and postabortion s-hCG. Good quality, randomized controlled trial evidence is needed to best inform practice.

Medical methods for first trimester abortion

BACKGROUND

Medical abortion became an alternative method of pregnancy termination following the development of prostaglandins and antiprogesterone in the 1970s and 1980s. Recently, synthesis inhibitors of oestrogen (such as letrozole) have also been used to enhance efficacy. The most widely researched drugs are prostaglandins (such as misoprostol, which has a strong uterotonic effect), mifepristone, mifepristone with prostaglandins, and letrozole with prostaglandins. More evidence is needed to identify the best dosage, regimen, and route of administration to optimise patient outcomes. This is an update of a review last published in 2011.

OBJECTIVES

To compare the effectiveness and side effects of different medical methods for first trimester abortion.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Global Health, and LILACs on 28 February 2021. We also searched Clinicaltrials.gov and the World Health Organization's (WHO) International Clinical Trials Registry Platform, and reference lists of retrieved papers.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that compared different medical methods for abortion before the 12th week of gestation. The primary outcome is failure to achieve complete abortion. Secondary outcomes are mortality, surgical evacuation, ongoing pregnancy at follow-up, time until passing of conceptus, blood transfusion, side effects and women's dissatisfaction with the method.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected and evaluated studies for inclusion, and assessed the risk of bias. We processed data using Review Manager 5 software. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 99 studies in the review (58 from the original review and 41 new studies). 1. Combined regimen mifepristone/prostaglandin Mifepristone dose: high-dose (600 mg) compared to low-dose (200 mg) mifepristone probably has similar effectiveness in achieving complete abortion (RR 1.07, 95% CI 0.87 to 1.33; I2 = 0%; 4 RCTs, 3494 women; moderate-certainty evidence). Prostaglandin dose: 800 µg misoprostol probably reduces abortion failure compared to 400 µg (RR 0.63, 95% CI 0.51 to 0.78; I2= 0%; 3 RCTs, 4424 women; moderate-certainty evidence). Prostaglandin timing: misoprostol administered on day one probably achieves more success on complete abortion than on day three (RR 1.94, 95% CI 1.05 to 3.58; 1489 women; 1 RCT; moderate-certainty evidence). Administration strategy: there may be no difference in failure of complete abortion with self-administration at home compared with hospital administration (RR 1.63, 95% CI 0.68 to 3.94; I2 = 84%; 2263 women; 4 RCTs; low-certainty evidence), but failure may be higher when administered by nurses in hospital compared to by doctors in hospital (RR 2.69, 95% CI 1.39 to 5.22; I2 = 66%; 3 RCTs, 3056 women; low-certainty evidence). Administration route: oral misoprostol probably leads to more failures than the vaginal route (RR 2.38, 95% CI 1.46 to 3.87; I2 = 39%; 3 RCTs, 1704 women; moderate-certainty evidence) and may be associated with more frequent side effects such as nausea (RR 1.14, 95% CI 1.03 to 1.26; I2 = 0%; 2 RCTs, 1380 women; low-certainty evidence) and diarrhoea (RR 1.80 95% CI 1.49 to 2.17; I2 = 0%; 2 RCTs, 1379 women). Compared with the vaginal route, complete abortion failure is probably lower with sublingual (RR 0.68, 95% CI 0.22 to 2.11; I2 = 59%; 2 RCTs, 3229 women; moderate-certainty evidence) and may be lower with buccal administration (RR 0.71, 95% CI 0.34 to 1.46; I2 = 0%; 2 RCTs, 479 women; low-certainty evidence), but sublingual or buccal routes may lead to more side effects. Women may experience more vomiting with sublingual compared to buccal administration (RR 1.33, 95% CI 1.01 to 1.77; low-certainty evidence). 2. Mifepristone alone versus combined regimen The efficacy of mifepristone alone in achieving complete abortion compared to combined mifepristone/prostaglandin up to 12 weeks is unclear (RR of failure 3.25, 95% CI 0.81 to 13.09; I2 = 83%; 3 RCTs, 273 women; very low-certainty evidence). 3. Prostaglandin alone versus combined regimen Nineteen studies compared prostaglandin alone to a combined regimen (prostaglandin combined with mifepristone, letrozole, estradiol valerate, tamoxifen, or methotrexate). Compared to any of the combination regimens, misoprostol alone may increase the risk for failure to achieve complete abortion (RR of failure 2.39, 95% CI 1.89 to 3.02; I2 = 64%; 18 RCTs, 3471 women; low-certainty evidence), and with more diarrhoea. 4. Prostaglandin alone (route of administration) Oral misoprostol alone may lead to more failures in complete abortion than the vaginal route (RR 3.68, 95% CI 1.56 to 8.71, 2 RCTs, 216 women; low-certainty evidence). Failure to achieve complete abortion may be slightly reduced with sublingual compared with vaginal (RR 0.69, 95% CI 0.37 to 1.28; I2 = 87%; 5 RCTs, 2705 women; low-certainty evidence) and oral administration (RR 0.58, 95% CI 0.11 to 2.99; I2 = 66%; 2 RCTs, 173 women). Failure to achieve complete abortion may be similar or slightly higher with sublingual administration compared to buccal administration (RR 1.11, 95% CI 0.71 to 1.74; 1 study, 401 women).

AUTHORS' CONCLUSIONS

Safe and effective medical abortion methods are available. Combined regimens (prostaglandin combined with mifepristone, letrozole, estradiol valerate, tamoxifen, or methotrexate) may be more effective than single agents (prostaglandin alone or mifepristone alone). In the combined regimen, the dose of mifepristone can probably be lowered to 200 mg without significantly decreasing effectiveness. Vaginal misoprostol is probably more effective than oral administration, and may have fewer side effects than sublingual or buccal. Some results are limited by the small numbers of participants on which they are based. Almost all studies were conducted in settings with good access to emergency services, which may limit the generalisability of these results.

Mifepristone and Misoprostol for Undesired Pregnancy of Unknown Location

OBJECTIVE

To compare immediate initiation with delayed initiation of medication abortion among patients with an undesired pregnancy of unknown location.

METHODS

This retrospective cohort study used electronic medical record data from the Planned Parenthood League of Massachusetts (2014-2019) for patients who requested medication abortion with a last menstrual period (LMP) of 42 days or less and pregnancy of unknown location (no gestational sac) on initial ultrasonogram. Clinicians could initiate medication abortion with mifepristone followed by misoprostol while simultaneously excluding ectopic pregnancy with serial serum human chorionic gonadotropin (hCG) testing (same-day-start group) or establish a diagnosis with serial hCG tests and repeat ultrasonogram before initiating treatment (delay-for-diagnosis group). We compared primary safety outcomes (time to diagnosis of pregnancy location [rule out ectopic], emergency department visits, adverse events, and nonadherence with follow-up) between groups. We also reported secondary efficacy outcomes: time to complete abortion, successful medication abortion (no uterine aspiration), and ongoing pregnancy.

RESULTS

Of 5,619 medication abortion visits for patients with an LMP of 42 days or less, 452 patients had pregnancy of unknown location (8.0%). Three patients underwent immediate uterine aspiration, 55 had same-day start, and 394 had delay for diagnosis. Thirty-one patients (7.9%), all in the delay-for-diagnosis group, were treated for ectopic pregnancy, including four that were ruptured. Among patients with no major ectopic pregnancy risk factors (n=432), same-day start had shorter time to diagnosis (median 5.0 days vs 9.0 days; P=.005), with no significant difference in emergency department visits (adjusted odds ratio [aOR] 0.90, 95% CI 0.43-1.88) or nonadherence with follow-up (aOR 0.92, 95% CI 0.39-2.15). Among patients who proceeded with abortion (n=270), same-day start had shorter time to complete abortion (median 5.0 days vs 19.0 days; P<.001). Of those who had medication abortion with known outcome (n=170), the rate of successful medication abortion was lower (85.4% vs 96.7%; P=.013) and the rate of ongoing pregnancy was higher (10.4% vs 2.5%; P=.041) among patients in the same-day-start group.

CONCLUSION

In patients with undesired pregnancy of unknown location, immediate initiation of medication abortion is associated with more rapid exclusion of ectopic pregnancy and pregnancy termination but lower abortion efficacy.

Prioritizing Desiredness in Pregnancy of Unknown Location: An Algorithm for Patient-Centered Care

Patient-centered care is one of the six aims for improvement in health care quality outlined by the National Academy of Medicine (previously known as the Institute of Medicine). We propose an algorithm for patients who are presenting with a pregnancy of unknown location that emphasizes pregnancy desiredness to improve patient-centered care. Health care professionals should assess pregnancy desiredness at a patient's initial consultation for evaluation of pregnancy of unknown location; desiredness, along with other clinical criteria, should guide management. For women with an undesired pregnancy, health care professionals should offer expedient active management. Uterine aspiration will allow for quick clinical diagnosis and resolution of the pregnancy. Alternatively, for women with a desired pregnancy or for those who are ambivalent, we recommend careful conservative management. Adopting this algorithm will recenter the patient in the complex management of pregnancy of unknown location.

Early medical abortion with self-administered low-dose mifepristone in combination with misoprostol

AIM

The aim of the present study was to investigate the safety and efficacy of low-dose mifepristone combined with self-administered misoprostol for termination of early pregnancy.

METHODS

A total of 533 women seeking medical abortion in early pregnancy (≤49 days since the last menstrual period) were divided randomly into hospital- (H-Mis, 250) and self- (S-Mis, 283) administered misoprostol groups. Women in two groups took 100 mg of oral mifepristone in hospital followed by 200 μg of sublingual misoprostol 24 h later in hospital or home. The primary outcome parameter was complete abortion without surgical intervention. Secondary outcomes were uterine bleeding, return of regular menses, side effects and patient acceptability.

RESULTS

High rates of complete abortion were observed for both the H-Mis group (243/250; 94.8%) and the S-Mis group (266/283; 94.0%). No significant differences in outcomes (complete abortion/failure rates) or side effects were observed between the two groups. General satisfaction rates were similar for the two groups (H-Mis, 231/250, 92.4%; S-Mis, 263/283, 92.9%; P > 0.05). Higher convenience of administration (H-Mis, 211/250, 84.4%; S-Mis, 270/283, 95.4%; P < 0.05) and privacy protection (H-Mis, 214/250, 85.6%; S-Mis, 267/283, 94.3%; P < 0.05) satisfaction rates were obtained for the S-Mis group than for the H-Mis group.

CONCLUSION

Self-administered sublingual misoprostol is as safe and effective as hospital-administered misoprostol following low-dose mifepristone to terminate early pregnancy (≤49 days of amenorrhoea) with fewer side effects.

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.