SU Non-Invasive Prenatal Testing 17/10 Flashcards
Non-Invasive Prenatal Testing (NIPT)
- is a method used to screen for certain genetic conditions in a fetus early in pregnancy
- that uses maternal blood to detect fetal chromosomal abnormalities
- NIPT works by analyzing cell-free fetal DNA (cfDNA) in the maternal bloodstream. This cfDNA originates from the placenta and is mixed with maternal cfDNA.
The fetal fraction, or the percentage of cfDNA from the fetus, is critical in determining the accuracy of the test. -
primarily detects trisomies such as Down syndrome (T21), Edwards syndrome (T18), and Patau syndrome (T13), which are associated with severe developmental and health issues.
The screening method can be expanded to detect other chromosomal abnormalities. - Previous Combined Test: Before NIPT, a combined test using ultrasound (nuchal translucency measurement) and blood analysis was used to assess the risk of trisomies. This method had a lower detection rate and higher false positives, requiring invasive tests like amniocentesis for confirmation.
Abstract
Non-Invasive Prenatal Testing (NIPT) has become a widely used method for detecting chromosomal abnormalities, such as trisomy 13 (Patau syndrome), trisomy 18 (Edwards syndrome), and trisomy 21 (Down syndrome), early in pregnancy. NIPT analyzes cell-free fetal DNA present in maternal blood to assess potential genetic anomalies, offering a non-invasive alternative to previous invasive techniques. With a high detection rate and low false positive rate, NIPT is more reliable than the older combined test, which involved ultrasound and blood analysis. This presentation covers the principles of NIPT, its practical application, data analysis methods, and the bioinformatics processes that ensure its accuracy. It also discusses methods to estimate fetal DNA fractions and how the technology has been implemented in clinical practice, particularly in Rotterdam.
