Cell-Free Fetal DNA in Plasma of Pregnant Women: Clinical Potential and Origin

Circulating fetal DNA in maternal plasma can be used for both fetal genetic testing and evaluation of complications of pregnancy. As a prenatal genetic test, the greatest advantage of using circulating fetal DNA is the lack of risk. This approach has been applied to the diagnosis of fetal gender, fetal Rhesus D (RhD) blood type, and fetal single-gene disorders. However, it only allows examination of disorders where the gene of interest is present in the fetal genome but absent from maternal DNA. Since most fetal DNA probably originates from villous trophoblasts, concentrations can be used to evaluate damage to trophoblasts, particularly in pathologic complications of pregnancy such as pre-eclampsia, invasive placenta, hyperemesis gravidarum, and trisomy 21. Fetal DNA in the plasma of pregnant women thus offers a new source of data that can be used in various clinical settings.