The present invention discloses administering steroid hormones to mammals to treat autoimmune related diseases, including post-partum auto immune diseases) and more particularly. Most preferably the invention uses estrogens, estranges, estriol or estrogen receptor active agents to prevent or ameliorate clinical symptoms of these ThI-mediated (cell-mediated) autoimmune diseases known to either have an initial onset following the birth of a child or which are exacerbated in patients in the postpartum period.