DNA Based Prenatal Test (NIPT test)

DNA Based Prenatal Test (NIPT test)

DNA Based Prenatal Test (NIPT test)

DNA Based Prenatal Test:

  • It is a non invasive test.
  • Most sensitive screening option for detecting trisomy 21, 18, and 13.
  • It is done as early as 10th week of pregnancy.
  • Looks for fragments of the fetus’s DNA in the mother’s blood.
  • It is a single blood draw from the mother.
  • Can also identify the fetus’s sex. (Read more: Gender Selection)
  • Takes 7-14 days until receiving the final report.
  • Yet not endorsed for twin pregnancies.

Evaluating the risk of possible chromosomal conditions such as:

  • Down syndrome/ trisomy 21
  • Edward’s syndrome/trisomy 18
  • Patau syndrome/trisomy 13
  • Monosomy X
  • Sex chromosome aneuploidy

NIPT Test indications:

  • Advanced maternal age (35 years old and more)
  • Positive serum screen result
  • Previous affected pregnancy
  • Abnormal fetal ultrasound findings
  • A parent carries a relevant Robertsonian translocation

But recent studies suggested that the test is recommended for for all pregnant women regardless of age or risk.


  • It can be done as early as 10 weeks of pregnancy.
  • No pregnancy loss risk comparing to other traditional screenings.
  • Accuracy:
    • a. Trisomy 21: DR (Detection Rate) 99.5%, FPR (False Positive Result) 0.05%
    • b. Trisomy 18: DR 97.7%, FPR 0.04%
    • c. Trisomy 13: DR 96.1%, FPR 0.06%

1 – 5% possibility that the test does not yield a result.

Also, obese women (weight over 81 kg) are at increased risk of receiving a test failure.

What if the results are positive?
Invasive diagnostic testing must be performed to confirm the results.

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