Fetal cells from maternal blood: Purpose, biological questions, technical challenges

The maternal peripheral blood circulation can serve as a source of fetal ce lls for the prenatal diagnosis of genetic abnormalities, eliminating the ne ed for fetal cell sampling by invasive techniques. However, the extreme sca rcity of these cells leads to a variety of biological questions and technic al hurdles on the way to a clinical test. On the biological side, we need t o know the numbers of fetal cells, their distinguishing properties, and the variables that affect these properties. On the technical side, we need to identify fetal cells and maximize both yield and purity of the isolation pr ocedure. Here we review the questions and challenges as they present themse lves in our specific approach to the fetal cell isolation project. We also briefly discuss the question of whether these cells could help to diagnose fetal infections.