Cellular sensitization in man and mice during pregnancy to fetal antigens as detected by lympholine assays.

Soluble extracts were prepared by the 3 M KC1 method from human mouse fetuses at different stages of development. As shown by macrophage electrophoretic mobility and by leukocyte migration inhibition tests a high percentage of pregnant women is sensitized to components of these extracts. The testing of pregnant mice of an inbred strain gave similar results. The available data support the view that some kind of cellular sensitization to fetal antigen may occur during pregnancy.