have you heard about the Non-Invasive Prenatal Testing (NIPT)?

have you heard about the Non-Invasive Prenatal Testing (NIPT)?

Cell-free fetal DNA (cffDNA) is fetal DNA circulating freely in the maternal blood stream. It can be sampled by venipuncture on the mother. Analysis of cffDNA provides a method of non-invasive prenatal diagnosis and testing.

Heard Non-Invasive Prenatal Testing

Cell free fetal DNA shedding into maternal bloodstream

cffDNA originates from the trophoblasts making up the placenta.[1][2] An average of 11%-13.4% of cell-free DNA in maternal blood is of fetal origin, although this varies widely amongst patients.[3] The fetal DNA is fragmented and makes its way into the maternal bloodstream via shedding of the placental microparticles into the maternal bloodstream (figure 1).[4] Studies have shown that cffDNA can first be observed as early as 7 weeks gestation, and the amount of cffDNA increases as the pregnancy progresses.[5] cffDNA diminishes quickly after the birth of the baby, so that it is no longer detectable in the maternal blood approximately 2 hours after birth.[6] cffDNA fragments are significantly smaller than the maternal DNA fragments in the bloodstream, with cffDNA fragments being approximately 200bp (base pairs) in size.[7] Many protocols to extract the fetal DNA from the maternal plasma use its size to distinguish it from the maternal DNA.[8][9]

Studies have looked at, and some have even optimized, protocols for testing for various issues, including non-compatible RhD factors, sex determination for X-linked genetic disordersand testing for single gene disorders.[10] Current studies are now looking at determining aneuploidies in the developing fetus.[11][12] These protocols can be done earlier than the current prenatal testing methods, and have no risk of spontaneous abortion, unlike current prenatal testing methods.[13] Non-invasive prenatal diagnosis (NIPD) and Non-invasive prenatal testing (NIPT) have been implemented in the UK and parts of the US; it has clear benefits above the standard tests of chorionic villi sample (CVS), amniocentesis,[14] and other techniques which have procedure-related miscarriage risks of about 1 in 100 pregnancies and 1 in 200 pregnancies, respectively.[15][16][17]

As a method of prenatal diagnosis, cell-free fetal DNA techniques share the same ethical and practical issues, such as the possibility of prenatal sex discernment and sex selection.[10]

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