Fetal liver transplants.

Transplants of hematopoietic stem cells derived from fetal liver during the second trimester of pregnancy can restore hematopoiesis in animals and humans with bone marrow failure. These cells also have a reduced likelihood of causing graft-versus-host disease. Because fetal liver derived hematopoietic stem cells are relatively pure and considerable proliferative potential, they may be reasonable targets for studies of gene modification. Other possible uses of fetal liver derived stem cells are also considered as are results of fetal liver transplants in animals and humans. These data are compared to alternative sources of hematopoietic stem cells including bone marrow and umbilical cord and adult blood.