What are the possible results of Non-Invasive Prenatal Testing? What is the chance of having a baby with Down syndrome?
This article will provide information about the results of NIPT test, including how to interpret the results.
What does the NIPT Test for ?
Non-invasive prenatal test (NIPT) is a test that checks for genetic defects and abnormalities in the unborn baby which is done as early as week 9 of pregnancy by using the latest genetic sequencing technology.
NIPT stands for ‘Non Invasive Prenatal Testing’. It is a means of testing for chromosomal abnormalities in the foetus by looking for certain genetic material in the mother’s blood.
Non-Invasive Prenatal Test (NIPT) is being performed on maternal blood for screening for genetic defect and abnormalities in the unborn baby. Most commonly for screening the most common fetal chromosome abnormalities such as trisomy21, trisomy18, trisomy13, Monosomy X, Triploidy and Microdeletions.
Who should get NIPT done?
With the age of the mother, there is higher risk of Down syndrome in the baby. In such condition, doctors recommend getting this test done. Generally, in following women NIPT is done
- women having history of genetic disorders in their family.
- Mother who might have been suspected for Trisomy 21,18 and 13.
- Mother’s age is 31 or above are recommended to do the test
- Women who have given previous baby with chromosomal abnormality (down syndrome)
- Women with IVF or previously suffered from habitual abortion.
- If the mother hasn’t tested for down syndrome in first trimester
- Wife or husband with genetic disorder
- Person with RH negative blood group
How NIPT Test is done?
After a few weeks of pregnancy, the baby’s DNA is mixed in the mother’s bloodstream and is therefore NIPT test is done from mother’s blood.
The sample of DNA is taken from the mother’s blood and the genetic information present in it is tested. During the process, it is confirmed that whether there is any abnormality in it or if there is any kind of risk to the child.
how long do NIPT test results take ?
NIPT test result usually take 2 to 3 week. You can get either positive or negative test result after giving the test sample from maternal blood.
How to Interpret Results of NIPT Test
The results of this NIPT test will have accuracy of this test is 97% to 99%. Let’s know about the NIPT test results. The result can be either positive or Negative.
NIPT Test negative
When the NIPT test is negative means that the risk of the child getting down syndrome is very low.
NIPT Test Positive
When the NIPT test is positive, the commonly found genetic disorder is common. The NIPT test positive is highly suggestive of down syndrome, turner syndrome, Edwards syndrome and Patau syndrome
Regarding this test, the test is only screening for these above genetic disorder in child for the possibility of these, however for better and more accurate complex testing, the doctors also recommend amniocentesis.
Result of NIPT Test and Down Syndrome
As said earlier, The NIPT test is very sensitive to diagnose down syndrome. The NIPT test is a non-invasive prenatal test (NIPT) that can be used during pregnancy to identify pregnant women at an increased risk of having a fetus with Down syndrome (TRISOMY 21).
When the results suggest the baby is likely to have down syndrome, further tests are done. chorionic villus sampling and amniocentesis test is being recommended to get more confirmed and accurate info.
Clinical utility of NIPT test Results
- Identifies for the Trisomy 21, 13 & 18, Monosomy X, Triploidy & Micro deletions.
- To differentiate between Maternal & Fetal DNA.
- The test can be used as early as 9 weeks of gestation however it is valid Between 10-24 weeks of gestation
- The test is so accurate
- NIPT test uses SNPs (Single Nucleotide Polymorphisms) in order to differentiate maternal from the fetal DNA.
- Sensitivity & Specificity of NIPT test is >99%
Conclusion
Result for NIPT test is a blood test that can accurately identify women who will have a positive result for trisomy 21 at a high chromosomal error risk as well as other genetic disorder