Non-invasive perinatal testing (NIPT) is an antenatal screening technique which has relatively recently come into practice. It relies on the detection of small amounts of cell free fetal DNA to be detected in the maternal bloodstream, hence allowing prenatal genetic diagnosis to occur by way of a maternal blood test.
Approximately 10% of cell free DNA in the maternal blood stream is cell free fetal DNA (cffDNA) - in fact representing DNA from the cytotrophoblast of the placenta. In the setting of a fetal trisomy such as Trisomy 21, current technologies can accurately detect the small relative increase in the number of chromosomal fragments related to the particular chromosome (e.g. chromosome 21 for Down syndrome) with a high degree of accuracy.
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- 2. Allyse M, Minear MA, Berson E et-al. Non-invasive prenatal testing: a review of international implementation and challenges. Int J Womens Health. 2015;7: 113-26. doi:10.2147/IJWH.S67124 - Free text at pubmed - Pubmed citation