Prenatal determination of fetal blood group status

Background and Objectives: The prenatal determination of fetal blood group status by molecular techniques has been used in the clinical management of alloimmunised pregnancies for seven years, in particular for the definition of fetal Ph D, c and E, K, Fy(a) and Jk(a) status. This has arisen in resp onse to the definition of the molecular bases of human blood group polymorp hism. Materials and Methods: PCR-based amplification assays have been desig ned to define fetal brood group status, where the source of template DNA is normally derived from amniotic fluid or chorionic villus. Recently, non-in vasive methods have been explored to obtain fetal DNA from maternal periphe ral blood. Results: PCR-based tests are now available to screen for all fet al medicine significant blood group antigens. The Rh system is the most com plex, and assays to define Ph genotype have been modified in reponse to our increased understanding of the molecular biology of this brood group syste m. Conclusion: Prenatal diagnosis of fetal blood group status is now in wid espread use in the clinical management of HDN. Non-invasive testing, if app lied in the clinical setting may invoke a dramatic increase in the numbers of pregnancies that maybe analysed prenatally.