Don't know for sure. No good evidence yet that endometriosis is a cause of recurrent miscarriage (2 or more losses). Endo. May affect embryo implantation, which affects getting pregnant not staying pregnant. Auto-immune antibodies (antiphospholipid antibodies or apa) are more common in women with endometriosis even with no losses. Apa cause some cases of recurrent miscarriage. Need big studies to find if linked or not.