Study on Combined Use of Letrozole, Mifepristone and Misoprostol in Termination of Pregnancy

Inclusion Criteria: * good general health * older than the age of legal consent (i.e. \>18 years old) * requesting medical abortion and eligible for abortion * on Day 1 of the study (day of letrozole and mifepristone administration) the duration of pregnancy not more than 63 days as confirmed by pelvic ultrasound examination * intrauterine pregnancy (intrauterine amniotic sac seen in US) * willing to use other than hormonal or intra-uterine contraception until the first menses after termination of pregnancy * if treatment should fail agrees to termination of pregnancy with the surgical method * willing and able to participate after the study has been explained * haemoglobin higher than 10g/L, normal liver and renal function Exclusion Criteria: * a history or evidence of adrenal pathology, steroid-dependent cancer, porphyria, diastolic pressure over 95mm Hg, bronchial asthma, arterial hypotension * a history or evidence of thrombo-embolism, severe or recurrent liver disease or pruritus of pregnancy * the regular use of prescription drugs before admission to the study * the presence of an IUCD in utero * breast-feeding * multiple pregnancies * heavy smoker of more than 20 cigarettes per day * any abnormal values in pre-treatment blood tests