RPL is defined as three or more consecutive pregnancy losses before the 20th week of gestation. The incidence of RPL is 3-5 %. After the second loss, there is already a higher risk of miscarriage complicating the next gestation.Whereas inherited and acquired (infections, smoking, etc.) factors have been implicated in the etiology of RPL most (50–60)% of the cases remain idiopathic. The etiology of RPL can be divided according to their therapeutic potential into treatable and currently untreatable causes. The treatable causes are structural uterine defects, endocrine dysfunction (luteal phase deficiency), thrombotic pregnancies (thrombophilias or autoantibodies), and immunologic disorders (immunoglobulins and immunization). The currently untreatable causes are genetic abnormalities and idiopathic etiologies.