IMMUNOLOGY OF NORMAL-PREGNANCY

Immune coexistence between mother and embryo is established very early in pregnancy. This coexistence involves alloimmune recognition, stimu lation of T helper 2 response, and suppression of T helper 1 cytotoxic response. Lack of immune recognition results in rejection of the embr yo by autoimmune reactivity and activation of cytotoxic natural killer cells. Relevance to autoimmune disease and infectious disease is also addressed.