Non-Invasive Prenatal Testing (NIPT)
Definition - What does Non-Invasive Prenatal Testing (NIPT) mean?
Non-Invasive Prenatal Testing (NIPT) is used to screen a fetus for genetic or chromosomal abnormalities. It analyzes fragments of the fetal DNA, called cell-free DNA (cfDNA) present in the blood of a pregnant woman. It can also be used to determine the sex of the baby and the rhesus (Rh) blood type.
NIPT is carried out in women who are at least 10 weeks pregnant to ascertain the risk for a number of genetic disorders in the unborn baby. It is not a routine screening test and is generally performed only in high-risk women.
NIPT is also referred to as prenatal cell-free DNA screening.
FertilitySmarts explains Non-Invasive Prenatal Testing (NIPT)
NIPT is performed just like any other blood test by withdrawing blood from the woman's arm. It is recommended for high-risk pregnant women who:
- Are past 35 years of age
- Have a positive triple, quadruple or first-trimester screen (indicative of a genetic abnormality)
- Have a positive finding on ultrasound suggesting aneuploidy
- Have a prior history of giving birth to a child with a genetic abnormality
- Have a previous history of miscarriage resulting from a chromosomal translocation
The chromosomal disorders that can be screened with NIPT include:
- Down syndrome (trisomy 21)
- Trisomy 18
- Trisomy 13
- Sex chromosome aneuploidies
- Disorders with chromosomal microdeletions like Prader-Willi syndrome
NIPT might be preferred over the first trimester and the quad screens as it produces fewer false positives. That said, prenatal cell-free DNA screening doesn't tell for sure if the baby actually has a genetic problem. In fact, it predicts the baby's likelihood of having a genetic problem.
Additionally, it doesn't screen for all the genetic disorders. Despite that, NIPT is one of the ideal tests to identify the risk of chromosomal disorders in babies born to high-risk women with an accuracy rate as high as 99%.
NIPT also allows these women to make decisions regarding more invasive tests like amniocentesis and chorionic villus sampling (CVS). If cell-free DNA (cfDNA) screening is positive, a doctor may suggest an amniocentesis or CVS.
The major drawback of NIPT is its cost, as it is not covered or covered partially by most of the health insurance companies. NIPT is also less effective in women who are obese or have conceived via IVF.