Stem cells should be the ideal treatment for fetuses with genetic disorders - their nascent immune systems could adopt the incoming cells seemingly without trouble. Yet these treatments have never worked. Until now.

For embryos with certain diseases like sickle cell anemia, stem cell implants should be the perfect medicine. The flexible immune system of the fetus should let the implant into their system, and replace the child's blood forming cells. Yet without fail, the fetus almost always rejects the implants, even when they're a match with the donors. According to new research, the most likely cause of this is the large amount of the mother's blood that is in the baby. It's her immune system that triggers the rejection.

Using blood stem cells that are a match for the mother — even if they're not a match for the embryo — are accepted well in mouse studies, and harvesting the implant cells from the mother works even better. This matching potentially opens up wide-ranging implications for the treatment of genetic disorders in babies, even before they're born.


Research published in Journal of Clinical Investigation