This is a case report of a 47-year-old patient that came to our Clinic due to bleeding during the 23rd week of twin pregnancy after in vitro fertilization-intracervical insemination/embryo transfer (IVF-ICI/ET) treatment. Prior to this pregnancy, this patient had had ten spontaneous miscarriages, eight of which following IVF-ICI/ET, and two following spontaneous conception, all in the eighth week of pregnancy. After several miscarriages by the age of 43, the patient was suggested to be tested for thrombophilia; it was then discovered that she had the methylenetetrahydrofolate reductase (MTHFR) gene defect, in the homozygous Tobiano (TT) form. Thus she was treated with cardiolipin and folic acid before pregnancy, and continued with folic acid after the pregnancy had been diagnosed. Fraxiparine 0.4 ml subcutaneous (s.c.) should be introduced from the second month of pregnancy until one day before delivery. It is a useful treatment for the patients with MTHFR defect, as it prevents miscarriage and promotes successful pregnancy.