Fetal Cells Persist in Maternal Tissue Years After Pregnancy

Intact fetal cells presumably are present in the maternal blood during every pregnancy and have even been used to analyze the genetic composition of the fetus. But do these cells persist in the mother after pregnancy, resulting in fetal-maternal microchimerism? These investigators sought to determine the frequency of fetal cells, believed to be mesenchymal stem cells (MSCs), in the tissue of women many years after giving birth to male infants.

The investigators collected bone marrow or rib sections from women (age range, 46-83) undergoing cardiopulmonary surgery. Male cells, as documented by Y fluorescence in situ hybridization, were sought in either paraffin blocks (rib sections) or blood or bone marrow. In all nine women who had previously…