Pregnancy – NIPT

Non-Invasive Prenatal Testing (NIPT) is a relatively recent advancement in prenatal screening. It analyzes small fragments of DNA that are circulating in a pregnant woman’s blood, known as cell-free DNA (cfDNA). These fragments come from the placenta and are representative of the fetus’s genetic material. Here are key aspects of NIPT:

  1. Purpose of NIPT: NIPT is primarily used to screen for chromosomal abnormalities in the fetus. The most common conditions it screens for include Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13) and Turner’s syndrom (X0).
  2. Procedure: NIPT is performed through a blood sample taken from the pregnant woman, usually after the 10th week of pregnancy. It is non-invasive, posing no risk to the fetus.
  3. Accuracy and Limitations:
    1. NIPT is highly accurate in detecting conditions like Down syndrome, with a high sensitivity (likelihood of correctly identifying a condition when it is present) and specificity (likelihood of correctly identifying the absence of a condition when it is not present).
    2. However, it is a screening test, not a diagnostic test. A positive result indicates a higher risk of a chromosomal abnormality but does not confirm it. Confirmatory diagnostic testing like amniocentesis or chorionic villus sampling (CVS) is recommended after a positive NIPT result.
    3. False positives and false negatives can occur, although they are relatively rare.
  4. Advantages Over Traditional Screening:
    1. NIPT is more accurate than traditional prenatal screening tests like the first-trimester combined test (Nucal U/S + blood PAPP-A & hCG)
    2. It can be done earlier in pregnancy compared to some other tests and has a lower risk of false positives.
  5. Ethical and Psychological Considerations: The ease and accuracy of NIPT raise various ethical issues, such as the potential for selective termination of pregnancies and the psychological impact of early detection of fetal abnormalities. Genetic counseling is often recommended alongside NIPT to help expectant parents understand and make informed decisions based on the test results.
  6. Accessibility and Cost: The NIPT is not covered by Medicare or Private Health Insurance.  Patients can expect to pay about $400 to $500 for an NIPT.

In summary, NIPT is a highly accurate, non-invasive screening tool for certain genetic conditions in the fetus. It offers expectant parents valuable information but should be complemented with genetic counseling and, if necessary, follow-up diagnostic testing.