Non-Invasive Prenatal Testing (NIPT) is a technique useful for screening certain genetic predispositions in a developing fetus. It is a type of genetic testing that involves analyzing small fragments of fetal DNA. The fetal DNA is also known as cell-free fetal DNA (cffDNA).
Fetal DNA is present in the mother’s blood. Processing the blood sample of the mother will help distinguish the fetal DNA from the mother’s DNA. The test results reveal necessary genetic information and valuable insights into its health and development.
About NIPT Test
Non-Invasive Prenatal Testing (NIPT) is a type of screening test that helps detect any genetic abnormalities in a developing fetus. The test requires the collection of the mother’s blood sample, as fetal DNA circulates in the maternal bloodstream.
NIPT test involves the evaluation of fetal DNA circulating in the maternal bloodstream. Fetal DNA to assess the risk of certain chromosomal abnormalities in the fetus.
Moreover, blood collection does not require any invasive procedures. In this way, there is no risk of harm to the developing fetus. Therefore, the NIPT test is considered safest over other fetal genetic tests.
NIPT Test Results Normal Range
While analyzing DNA fragments during the NIPT test, the lab expert checks for some primary conditions through screening. It detects the DNA for conditions like trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome).
Let us see what constitutes a “normal” range or result for the NIPT test:
- Trisomy 21 (Down Syndrome): It is a genetic disorder that occurs due to the presence of an extra copy of chromosome 21. The extra genetic material impacts the normal development of the fetus. It contributes to the characteristic physical features and developmental challenges associated with the condition. Down syndrome typically causes individuals to have distinct facial features and mild to moderate intellectual disability. Such individuals may also have various health issues related to the heart, kidneys, thyroid, respiratory system, etc.
- Trisomy 18 (Edwards Syndrome): This rare condition is a genetic disorder due to an extra copy of chromosome 18. The condition has serious consequences leading to physical abnormalities. It affects fetal growth and development. Babies with this genetic condition often have abnormalities in various organs. They are born with low weight and have an unusual-looking face or head. Such babies may have several common features such as heart defects, clenched fists, and overlapping fingers. The survival rate for Edwards Syndrome is generally very low. Many affected infants fail to survive beyond the first year of life.
- Trisomy 13 (Patau Syndrome): In this type of genetic disorder, the fetus may have an extra copy of chromosome 13. It leads to severe developmental and physical abnormalities.The baby may be born with heart issues, intellectual disability, or brain or spinal cord defects. They may also have small or poorly developed eyes, cleft lip or palate, and extra fingers or toes. Most infants with this condition do not survive beyond the first few weeks or months of life. The prognosis of this condition is generally very poor.
- Sex Chromosome Aneuploidies: These type of are genetic conditions occur due to an abnormal number of sex chromosomes (X and Y). Such abnormalities can contribute to disabilities stemming from various developmental defects and physical differences. Some common examples of Sex Chromosome Aneuploidies include, Turner Syndrome (45,X), Triple X Syndrome (47,XXX), Klinefelter Syndrome (47,XXY), and XYY Syndrome (47,XYY). Turner Syndrome and Triple X Syndrome occur in females only, similarly Klinefelter Syndrome and XYY Syndrome are related to males only. Individuals with Turner Syndrome have short body stature, fertility problems, and issues related to puberty. Those with Triple X Syndrome have tall body stature and they may have learning difficulties.
NIPT Test Results Normal Range
The result interpretation for each of the genetic conditions listed above are as follows:
- Trisomy 21 (Down Syndrome): When the NIPT test for Trisomy 21 (Down Syndrome) is normal, it indicates low risk or possibility. The fetus may not have Trisomy 21 (Down Syndrome). Whereas, when results are positive, then the likelihood of the fetus having Trisomy 21 (Down Syndrome) is quite high. In such cases, healthcare providers suggest further tests for confirmation.
- Trisomy 18 (Edwards Syndrome): If the result is normal or low risk, then the probability of Edwards Syndrome is low in the fetus. But if the results are positive or high risk, then the fetus is highly likely to have a predisposition to the condition.
- Trisomy 13 (Patau Syndrome): Normal or low risk in the results indicates a low probability of the condition. However, results showing positive or high-risk predict higher chances of having the condition. In such cases, healthcare providers suggest additional tests for confirmation.
- Sex Chromosome Aneuploidies: When the results come out to be normal, it indicates low risk and low possibility of genetic abnormalities associated with these conditions. Contrary to that, if the results show positive indications, hinting towards high risk, then the probability of the fetus having any genetic condition is very likely.
To confirm that the fetus has a genetic predisposition to some genetic disorder, the healthcare provider will suggest further tests.
Benefits Of NIPT Test
Non-Invasive Prenatal Testing (NIPT) offers several benefits, which can help expectant parents make effective decisions. Several potential benefits of NIPT are as follows:
- Non-Invasive: NIPT is a type of non-invasive technique that requires only an expectant mother’s blood sample. It is safer compared to the invasive tests, as there is no risk to the fetus.
- Early Detection: With NIPT, the presence of genetic conditions can be detected as early as the 10th week of pregnancy. It helps with the early detection of potential genetic abnormalities, which provides more time for decision-making and planning.
- High Accuracy: NIPT can provide highly accurate results by detecting common chromosomal abnormalities in the fetus. It can detect conditions like trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome).
- No Risk To The Fetus: Invasive tests enhance the risk of miscarriage or infection to the fetus. However, in the case of NIPT, there is no such risk.
Conclusion
When the result of the NIPT test is normal, then it is unlikely that the fetus has a certain genetic condition. However, if the results are positive then there is a high chance that the fetus might have a certain genetic condition.
Healthcare providers will recommend several other tests to fully confirm the presence of genetic abnormalities. Confirmatory tests will help healthcare providers and expectant parents with critical decision-making and management.
