[The fetal-maternal interface. Description of its elements from an immunologic perspective].

The authors describe the different elements that can change the immunological response at the feto-maternal interface having studied the increasingly large literature on the subject. They consider first the nature of the interface and how trophoblastic antigens occur and then they point out the type and the role played by the different numerous decidual cells that take part in recognising, activating and regulating the immune system there. This general review is justified because local immunological phenomena seem to be important for the survival and the development of the feto-placental unit. They are also for immuno-suppressant mechanisms and immuno-tropic mechanisms. These phenomena, however important they may be, make it necessary to recognise one or more embryonic or trophoblastic antigens acting on the maternal immunological system.