This document outlines various etiological factors that can cause recurrent pregnancy loss. It groups the factors into categories including genital, endocrine and metabolic, anatomic, infections, immunologic, thrombofilias, and others. Some specific causes mentioned are chromosomal abnormalities, deficiencies in progesterone or thyroid hormones, cervical incompetence, viral or bacterial infections, autoimmune disorders, and blood group incompatibilities.