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

Abstract

This study aimed to investigate the effectiveness and safety of lower doses of mifepristone combined with misoprostol for the termination of ultra-early pregnancy. A total of 2500 women with ultra-early pregnancy (amenorrhea ≤ 35 days) were randomly divided into 5 groups with gradually decreased dose of oral mifepristone from 150 to 50 mg followed by 200 µg of oral misoprostol 24 hours later. The primary end point was complete abortion without surgical intervention. Secondary end points were vaginal bleeding, return of menses, and side effects. Rates of complete abortion were high in all groups. Moreover, the lower doses of mifepristone led to shorter vaginal bleeding period, the return of menses on the expected date, and fewer side effects. Lower doses of mifepristone combined with 200 µg of misoprostol are as effective and safe as higher doses of this combination for the termination of ultra-early pregnancy with lower possibility of vaginal bleeding and side effects.

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

“…The present results demonstrated that self‐administration of low‐dose misoprostol following mifepristone is as safe and effective as an equivalent dose regimen with hospital‐administered misoprostol, with the H‐Mis and S‐Mis groups in this study experiencing similar success rates and occurrence rates for side effects. These findings extend our earlier findings showing that low‐dose mifepristone combined with misoprostol could is a safe and effective method of very early pregnancy termination (≤35 days of amenorrhoea) or emergency contraception …”

“…found that reducing the mifepristone dose by two thirds, from 600 to 200 mg, reduced adverse effects without reducing efficacy . Furthermore, in large‐scale studies, our research group has found that efficacy for very early pregnancy termination was maintained with even lower doses of mifepristone (50–150 mg) combined with low‐dose misoprostol (200–400 μg), with similar minor side effects being observed across these dose ranges and with the lower dosages resulting in less irregular uterine bleeding . More recently, in 2015, we found that with very‐low‐dose mifepristone (50 mg) and misoprostol (200 μg) taken at the time of expected menstruation was efficacious and highly acceptable as a routine (or emergency) contraceptive .…”

“…Since the introduction of mifespristone in the 1980s, its combination with misoprostol for pregnancy termination has been subjected to substantial research internationally . The emergence of medical abortion regimens over the past decade has increased attention on very early termination of pregnancy.…”

“…Since the introduction of mifespristone in the 1980s, its combination with misoprostol for pregnancy termination has been subjected to substantial research internationally. [1][2][3][4] The emergence of medical abortion regimens over the past decade has increased attention on very early termination of pregnancy. Mifepristone was found out to influence the human luteal phase endometrium by reducing stromal edema, increasing venular diameter, causing erythrocyte and leukocyte diapedesis, focal hemorrhage and degeneration of the stromal extracellular matrix, thus initiating the eventual degradation of the endometrium.…”

“…Mifepristone was found out to influence the human luteal phase endometrium by reducing stromal edema, increasing venular diameter, causing erythrocyte and leukocyte diapedesis, focal hemorrhage and degeneration of the stromal extracellular matrix, thus initiating the eventual degradation of the endometrium. [5][6][7] The effectiveness of high-dose mifepristone and misoprostol for abortion is well established, with the earliest medical abortion regimen involving 600 mg of mifepristone, followed 48 h later by 800 μg of misoprostol in women who are less than 49-day pregnant, counting from the last menstrual period (LMP). 8 In systematic review about nine relatively high mifepristone dosage (200 mg) plus misoprostol (400 μg) studies, adverse effects rates, such as pain, nausea and vomiting are reported high, even up to 90%.…”