Also known as NIPS (Noninvasive Prenatal Screening), NIPT (Noninvasive Prenatal Testing) is a diagnostic technique for estimating the risk that the baby may be born with genetic problems.
This screening method breaks down small DNA strands found in the blood of the pregnant female. These DNA strands are found outside the cells and free-circulating hence their name cell-free DNA or cfDNA in short.
These smaller fragments typically consist of no more than 200 DNA base pairs or building blocks. They also emerge during cell death and their contents are split and released into the blood.
When a woman becomes pregnant, her blood circulation will feature a combination of cell-free DNA that originates from her cells along with those from the placenta, a temporary organ/tissue that connects the baby with the mother’s bloodstream for nourishment.
As specified earlier, these cells are released during pregnancy into the mother’s blood supply. The genetic code inside these cells is typically a copy of the genetic code of the developing baby.
Based on the above fact, cell-free DNA analysis can give physicians a good glimpse of potential genetic issues with the baby and therefore serve as a solid pre-birth diagnostic check. One of the biggest strengths of this method is that it doesn’t negatively affect the baby.
The NIPT screening test is useful for gauging the odds of a baby developing Down, Edwards, or Patau Syndrome, all of which refer to Trisomy 21, Trisomy 18, and Trisomy 13 respectively. The term “trisomy” refers to the occasion when three (instead of two as usual) replicates of a chromosome occur.
Down syndrome occurs more frequently as opposed to Edwards and Patau syndromes, which are rarer in prevalence. However, both Edwards and Patau syndromes are life-threatening and many babies suffering from these rare genetic issues do not live past a few months or years.
If parents ask for a baby gender test, the accuracy of the method surpasses 99%. In extreme and uncommon cases, there may not be enough pointers that determine the sex of the fetus and therefore the test will be deemed as a “sex determination failure”. This failure, though, will not adversely impact the trisomy test outcomes.
$13,500 to $23,000
When a woman gets pregnant, the placenta releases a cell-free genetic code that enters the blood circulation of the mother. This causes the blood sample of the mother to include a combination of baby and mother-cell-free genetic code (DNA). This cell-free DNA is used to detect a 13, 18, or 21 trisomy issue that may exist in the fetus of the unborn baby.
It involves taking a quick blood sample from the mother using a syringe and a needle. There is no reason to worry as this method is safe for both the mother and the baby and doesn’t disrupt the pregnancy.
The blood sample is then given to a lab, where a physician will analyze it to find any potentially cell-free DNA that indicates genetic problems. Once the test results are complete, your physician will most likely combine them with the outcomes of the ultrasound or translucency test to find out whether further tests are necessary.
Based on the previous test results, your doctor may suggest amniocentesis to validate the results and possibly look out for other genetic problems that the previous tests could not detect.
Are you considering getting yourself tested for cell-free DNA? It’s best to consult with your doctor for all the details and of course its availability first.
Your doctor or genetic advisor will break down all the potential outcomes that may emerge after testing and how these affect you and your child.
Don’t forget to discuss with your doctor on any questions or worries you may have regarding the screening procedure.
Test results usually come within 14 days from the sample date.
If the result comes out “normal”, “negative”, or “low risk”, this means your baby has a low chance of having genetic abnormalities.
However, if the outcome is “high risk”, “positive”, or “abnormal”, there is a high chance your baby has a genetic abnormality.
Any of these irregular results may require additional testing e.g. villus testing or amniocentesis to be confirmed.
NIPT/NIPS DNA testing has no health complications for you or your child. While it can be a stressful process, it prevents the need for getting more drastic tests or screening procedures during pregnancy.
One thing to keep in mind is that NIPT/NIPS testing doesn’t detect all genetic irregularities and is not 100% accurate. Having a normal or negative result is not a 100% guarantee that your baby is normal and your pregnancy won’t be affected.
How can get the most of NIPT/NIPS testing?
Conventional testing is available during the first trimester of your pregnancy and it’s called FTCT (First Trimester Combined Test). It involves the use of ultrasound technology to estimate the NT (Nuchal Translucency) count and blood screening test.
This detection test has an accuracy rate between 85-90% but may still help give an idea of possible mother and baby abnormalities.
The IONA trademarked test is currently the only screening measure that gives the choice of including the outcome of the FTCT test in the picture to offer a more complete and accurate result. However, you can get tested for trisomy DNA without getting an extra FTCT test.
Many pregnant females go for an IONA test within 10 weeks of pregnancy after an initial ultrasound check, which has to be done first before IONA screening.
This implies that a lower number of pregnant women will be subject to additional and invasive screening tests such as amniocentesis or Chorionic villus sampling (CVS), which are troublesome and slightly risky for the mother and the baby.
Who is the ideal candidate for this test? Am I a good candidate?
You can have this test ideally if you’ve been pregnant for 10 weeks with single or twin babies, or if you have a surrogate pregnancy with donor eggs.
How do experts report and interpret NIPT screening results?
Results are typically split into high or low risk of genetic irregularities. If the result falls under the “low risk” category, there is a low chance of having a baby affected by 13, 18, or 21 trisomy anomalies.
If the result is “high-risk”, it means there is a high chance for trisomy and the test results should be validated by a subsequent and more invasive prenatal testing such as CVS or amniocentesis.
If the test has “no result”, which is very uncommon, it means that there is not enough or clear sample of cell-free DNA to get an accurate result. In this case, your doctor may draw a blood sample from you again and re-restart the testing process.
Keep in mind that if your doctor or genetic expert finds any genetic irregularities, these can not be reversed. If your unborn baby appears to have Down syndrome, for instance, you will have to decide whether you want to proceed with the pregnancy as usual or not.
Additionally, you will have to be familiar with all the actions you should take to take care of your baby both during pregnancy and once it’s over. Don’t hesitate to discuss your options with your doctor.
Is the screening process invasive? How?
NIPT is categorized as non-invasive as it involves getting a blood sample from the mother without bearing any risk for the mother or the baby. NIPT/NIPS is a screening method, something that implies that it won’t offer a definite answer or whether the baby has a genetic syndrome.
The screening check can only gauge the odds of having a certain genetic issue. For example, in some situations, NIPT tests may show a heightened risk for a genetic irregularity that affects the baby but there is actually a low risk that does not affect the baby, giving a “false positive”.
On the contrary, there is also a chance of “false negative” where the initial test gives a low-risk/negative result but the risk is actually much higher. Due to the fact that NIPT examines both the cell-free DNA of the mother and the baby, it may also find genetic abnormalities in the mother.
At what stage of pregnancy can I have a NIPT test?
You may have, upon initial consultation with your doctor, a NIPT test once 9 weeks of pregnancy have passed, which is a bit earlier than other prenatal screening checks.
Compared to NIPT, nuchal translucency screening is performed between the 11th and 13th week of pregnancy and CVS can be performed between the 10th and 13th week of pregnancy.
Likewise, the quad test can be done between the 14th and 22nd week and amniocentesis is typically done between the 16th and 18th week of pregnancy. In some cases, however, amniocentesis may be done much later in weeks 23 or 24.
Is NIPT highly accurate?
Studies have shown that NIPT screening tests generate fewer false results compared to typical blood tests conducted during the first three months of pregnancy e.g. quad screening.
Additional studies also suggest that NIPT tests have a high accuracy compared to typical screenings in determining the risk of a baby having Down or Edwards trisomy syndrome.