Abstract: The present invention provides systems, apparatuses, and methods to detect the presence of fetal cells when mixed with a population of maternal cells in a sample and to test fetal abnormalities, i.e. aneuploidy. In addition, the present invention provides methods to determine when there are insufficient fetal cells for a determination and report a non-informative case. The present invention involves quantifying regions of genomic DNA from a mixed sample. More particularly the invention involves quantifying DNA polymorphisms from the mixed sample.