Non-Invasive Prenatal Testing (NIPT)-
At present, there are 2 options to ascertain the chromosome health of a foetus in pregnant women:
- Non-invasive Method. e.g. Combined test(NIPT).
- Invasive Method. This is a diagnostic test with 100% detection for the aneuploidies but there is a small risk of miscarriage. e.g. CVS and amniocentesis
- NIPT, is a technique which analyses cell-free fetal DNA circulating in maternal blood, for prenatal screening and testing of trisomy 21, trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome); we can also screen for other abnormalities including triploidy and microdeletion.
- The testing is non-invasive, involving a maternal blood draw, so the pregnancy is not put at risk for miscarriage or other adverse outcomes associated with invasive testing procedures.
- DNA from the fetus circulates in maternal blood. Unlike intact fetal cells in maternal blood, which can persist for years after a pregnancy, circulating cell-free fetal DNA (ccffDNA) results from the breakdown of fetal cells (mostly placental) and clears from the maternal system within hours. Fetal DNA detected during a pregnancy, therefore, represents DNA from the current fetus.
- The proportion fetal DNA derived from the placenta with respect to total amount of cfDNA is known as the fetal fraction.
Indications for NIPT:
- advanced maternal age
- an abnormal serum screen
- personal or family history of aneuploidy
- abnormal ultrasound
- The NIPT test requires taking a small maternal blood sample. cfDNA in the maternal blood is then analysed with our proprietary genetic sequencing technology and bioinformatics pipelines to screen for any chromosomal abnormality in the foetus.