Researchers in the US recently compared the efficacy and safety of mifepristone and misoprostol in managing early pregnancy loss.
Miscarriage during the first trimester of pregnancy is a common complication that affects nearly 1 million women in the United States every year. Most women experience early pregnancy loss before showing any symptoms. Hence, there has been a growing interest towards non-surgical treatment options for managing pregnancy loss. Still, most women prefer surgical or medical management of miscarriage, as the control over the management of miscarriage may provide some relief from the emotional stress related to the pregnancy loss.
Misoprostol allows for fast removal of fetus without surgery
Misoprostol is a drug that allows for planned and quicker removal of the fetus that is unable to survive after birth, without a surgical procedure. This drug can be administered vaginally by a woman herself, which allows the fetus removal to occur in the privacy of a woman’s home at any time she chooses. However, the standard dose of misoprostol (800 μg) has a low efficacy among women with a closed cervical opening. Hence 15% to 40% of women require a second dose of misoprostol. This leads to prolonged treatment period and may require uterine clearing, which many women may wish to avoid. The rate of failure decreases the clinical usefulness of this approach.
Mifepristone induces contractions to remove the fetus
Mifepristone is a steroid that prepares the muscle tissue of the uterus and the cervix for forceful and powerful contractions in order to expel the fetus. Previous studies on the combination of mifepristone and misoprostol for early pregnancy loss have found efficacy rates between 52 to 95%. To date, using mifepristone as a treatment for early pregnancy loss has not been clear.
A team of researchers from the United States conducted a study compare the efficacy and safety of pretreatment with mifepristone before use of misoprostol. They compared this to misoprostol use alone in managing early pregnancy loss.
Pretreatment with mifepristone followed by misoprostol resulted in more successful management of early pregnancy loss
The researchers conducted the Comparative Effectiveness of Pregnancy Failure Management Regimens (PreFaiR) trial on women who had been diagnosed with failed early pregnancy or fetal death from May 2014 to April 2017. Their findings were published in The New England Journal of Medicine.
The participants were randomly assigned to receive pretreatment with 200 mg of mifepristone, given orally, followed by 800 μg of misoprostol administered vaginally, approximately 24 hours later. This group was assigned as the mifepristone-pretreatment group.
The other group was given standard 800 μg misoprostol therapy, administered vaginally and was called as the misoprostol-alone group.
The researchers evaluated the participants one to four days after using misoprostol. The examination was done by an investigator who was unaware of the treatment-group assignments. Participants were followed for a 30-day period.
The results of the study showed that pretreatment with mifepristone followed by misoprostol treatment resulted in a better and more successful medical management of early pregnancy loss as compared to misoprostol alone treatment.
Written by Pratibha Duggal
(1) Schreiber CA, Creinin MD, Atrio J, Sonalkar S, Ratcliffe SJ, Barnhart KT. Mifepristone Pretreatment for the Medical Management of Early Pregnancy Loss. N Engl J Med. 2018:378(23).
(2) Free Medical Dictionary. https://medical-dictionary.thefreedictionary.com/inevitable+abortion