The purpose of this study is to compare the efficacy, safety and acceptability of pre-treatment with mifepristone and misoprostol compared to misoprostol alone in the medical termination of pregnancy by mifepristone EC failure.

Women usually request an abortion when they have experienced an emergency contraception (EC) failure; this population represents 13% of all early pregnancy terminations in China. Many women would prefer to choose a medical abortion in order to avoid anesthesia, over a surgical operation. However, medical termination of a pregnancy after mifepristone EC failure has not been studied although it has already been extensively practiced by empirical means in China. There is no clarification in literature as to whether mifepristone is still effective in medical abortion with its previous failure experience in EC. This randomized study was aimed to compare the efficacy, safety and acceptability of pre-treatment with mifepristone and misoprostol compared to misoprostol alone in the medical termination of pregnancy by mifepristone EC failure.

Inclusion Criteria:

• Participants included in the study were women aged 16 years or older
• with good general health,
• experiencing a mifepristone emergency contraception failure,
• presenting an intrauterine singleton pregnancy confirmed by pelvic ultrasound scan, with a crown-rump length compatible within 56 days of gestation at the enrolled day, and
• seeking a medical abortion for unwanted pregnancy.
• Women who had a threatened abortion or a failure pregnancy were also included.
• Participants were required to sign an informed consent form before enrolment, willing to comply with the schedule of follow-up visits and willing to undergo surgical aspiration if indicated.

Exclusion Criteria:

• The exclusion criteria included suspected or proven ectopic pregnancy,
• allergy or contraindications for mifepristone (chronic systemic corticosteroid therapy, adrenal insufficiency) or misoprostol (hypertension, mitral stenosis, severe asthma, glaucoma, sickle cell anemia and hypotension),
• history or evidence of thromboembolism, cardiovascular disease or liver disease, hemoglobin ≤ 90 g/l, heavy smoking (more than 10 per day),
• presence of an intrauterine device, and breastfeeding.
• Other exclusion criteria included participants who had EC failure because incorrect use, for example, having further unprotected intercourse after EC.