NIPT (Non-Invasive Prenatal Testing)

Function

Non-Invasive Prenatal Testing (NIPT), also known as cell-free DNA (cfDNA) screening, analyzes small fragments of DNA that are circulating in a pregnant woman's blood. Most of this DNA comes from the mother, but a small percentage (the fetal fraction) comes from the placenta. Since the placenta usually has the same genetic makeup as the fetus, analyzing this DNA allows for the screening of certain genetic abnormalities without risk to the pregnancy.

Why it is Ordered

NIPT is a screening tool used to assess the risk of chromosomal disorders. It is most commonly used to screen for Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome), and Trisomy 13 (Patau syndrome). It can also screen for sex chromosome abnormalities (like Turner or Klinefelter syndrome) and can determine the biological sex of the fetus as early as 10 weeks into pregnancy.

Associated Conditions

• Aneuploidies: Abnormal number of chromosomes.
• Microdeletions: Small missing pieces of chromosomes (e.g., DiGeorge syndrome), though NIPT is less accurate for these than for whole-chromosome issues.
• Triploidy: Three sets of every chromosome.

Important Consideration

NIPT is a screening test, not a diagnostic test. A 'High Risk' result requires confirmation via invasive procedures like Amniocentesis or Chorionic Villus Sampling (CVS).