Fetal Cells in Maternal Blood

Abstract

Itis wellknown thatfetal cells circ ulate in the maternal peripheralblood during pregnancy, although it is believed that their absolute number is very small. However, recovery and analysis of those cells would permit noninvasive prenatal diagnosis, which would avoid the procedure related risks inherent to current invasive techniques. Expected fetal cells present in maternal circulation are nucleated and nonnucleated red blood cells, white blood cells, hematopoietic stem cells and trophoblast cells (Gänshirt et al. 1995 a, 1995b). Our work has been focused on the isolation of nucleated red blood cells (NRBCs). One reason Fetal nucleated red blood cells have already been successfully isolated from maternal circulation and is that they are very abundant in early peripheral fetal blood, thus they seem to be a promising target for isolation in early gestation. However NRBCs are rare in adult circulation. This means fetal NRBCs can be enriched using tissue specific antibodies — whereas enrichment of fetal white cells requires individual specific antibodies in order to discriminate between the few fetal and the vast majority of maternal white cells. Also fetal red cells have a relatively short life span and thus they are likely to derive from a current pregnancy.