Immunological aspects of pathological pregnancy (infertility immunology).

As, theoretically, any of the many mechanisms that appear to operate in normal pregnancy to maintain maternofetal immunologic balance could be altered in pathologic pregnancy, a detailed study of the known immunological aspects of pathological pregnancy is given. After looking into the parental genetic heterozygosity and fertility, a good explanation of the antifetal immunoresponse by the pregnant mother including the antibody formation is shown. The placental transport versus trapping of immunoglobulins is described in detail and it is also shown that the placenta is a source of a number of agents that inhibit cell-mediated immunity (HCG, HPL and steroids). These substances may affect a local inhibition of maternal cell-mediated immunity in the vicinity of the trophoblast. The placenta serves as an effective barrier for transfer of immunocompetent maternal lymphocytes to the fetus. The paramount role of the trophoblast as a barrier, while itself escaping immunologic destruction, calls for further studies.