Mifepristone: Better for Managing Early Miscarriage

— Used prior to misoprostol, 25% higher rate of complete expulsion

MedicalToday

Women treated with mifepristone followed by misoprostol after a first-term pregnancy loss had a higher rate of complete expulsion and less frequent rates of uterine aspiration compared with misoprostol treatment alone, a randomized trial found.

Complete expulsion after one dose of misoprostol was reported in 83.8% of women who were pretreated with mifepristone compared with 67.1% of women who were treated with misoprostol alone (RR 1.25, 95% CI 1.09-1.43), reported Courtney A. Schreiber MD, of the University of Pennsylvania, and colleagues.

Moreover, uterine aspiration was performed in a smaller portion of women in the mifepristone pre-treatment group compared with misoprostol alone (8.8% versus 23.5% RR 0.37, 95% CI 0.21-0.68), they wrote in the

They noted that medical management of early pregnancy loss, which can include anembryonic gestation and embryonic or fetal death, inevitable abortion, or incomplete abortion, is not only recommended by the (ACOG) and the (WHO), but is "highly desired by many women."

However, there are some drawbacks to this treatment, namely that the standard dose administered vaginally has "low efficacy among women with a closed cervical os," the authors said, with 15% to 40% of women requiring a second dose. A 2016 study showed that this rate of failure of this strategy in clinical practice.

But studies involving combination treatment with mifepristone have found a range of effectiveness, and a noted that this is in part due to "heterogeneity in study designs and outcome definitions."

Researchers examined about 300 women with either an anembryonic gestation or where embryonic or fetal death was confirmed. These non-viable intrauterine pregnancies were from 5 to 12 completed weeks gestation. They were randomized to receive either 200 mg of mifepristone orally, followed by 800 μg of misoprostol vaginally, or just 800 μg of misoprostol alone.

The primary outcome was the defined as the gestational sac expulsion with one dose of misoprostol by the first follow-up visit and no additional intervention within 30 days of treatment.

In addition to treatment success, the authors also noted that by day 30, the cumulative rate of gestational sac expulsion with up to two doses of misoprostol was 91.2% compared with 75.8% in the misoprostol alone group (RR 1.20, 95% CI 1.08-1.33).

Examining adverse events, there were no significant differences between groups in mean scores for bleeding intensity or pain, the authors said. There were five serious adverse events reported in the mifepristone pretreatment group and three in the misoprostol alone group. While the portion of patients with bleeding resulting in a blood transfusion was higher in the mifepristone pretreatment group versus the misoprostol alone group (2.0% versus 0.7%, respectively), there was no significant difference between the two.

An by Carolyn L. Westhoff, MD, of Columbia University in New York City, characterized these results as supporting use of the sequential regimen as "standard of care."

"These results provide strong evidence that the sequential regimen of mifepristone followed by misoprostol is safe and is superior to misoprostol alone in attaining quick treatment success and avoiding an aspiration procedure," she added.

Westhoff also noted another issue -- that mifepristone is regulated by the FDA and requires a Risk Evaluation and Management Strategy (REMS), which may prevent some women from accessing the treatment.

"The REMS requirement for mifepristone prevents prescription sales in retail pharmacies," she wrote. "Thus, any patient with miscarriage who might prefer this treatment must find a clinician who stocks mifepristone in the office."

Disclosures

The study was supported by the NIH National Institute of Child Health and Human Development.

Schreiber disclosed no relevant relationships with industry. One co-author disclosed support from Danco Laboratories.

Westhoff disclosed support from Planned Parenthood, Merck, Bayer, Agile Therapeutics, Cooper Surgical, Allergan, and Elsevier.

Primary Source

New England Journal of Medicine

Schreiber CA, et al "Mifepristone pretreatment for the medical management of early pregnancy loss" N Engl J Med 2018; DOI:10.1056/NEJMoa171526.

Secondary Source

New England Journal of Medicine

Westhoff CL "A better medical regimen for the management of miscarriage" N Engl J Med 2018; DOI:10.1056/NEJMe1803491.