Many immunological factors may play a role in the failure of childbearing success. Various autoimmune diseases can cause impregnation disorders and early miscarriage. Diagnostics of these diseases are made difficult by the fact that they often do not cause symptoms, thus their suspicion arises at first when the patient is intent on becoming pregnant. Rheumatologic and immunological examination is recommended in case of multiple abortion and infertility. In 0.5%, immunological problems are the cause of miscarriage.