What are Non-Invasive Prenatal Tests Used For?
Non-invasive prenatal tests are used to screen for chromosomal abnormalities such as Down syndrome, as well as other genetic disorders. Pieces of your baby’s DNA are present in your bloodstream during pregnancy, and non-invasive screening tests can identify the likelihood of your baby being born with a chromosomal disorder. These tests are considered to be highly accurate and do not increase the chances of miscarriage. The results of non-invasive prenatal testing will help your doctor determine if any additional testing is necessary. This type of testing can also detect the gender of your baby.
MaterniT21™ PLUS Testing in NJ
MaterniT21™ PLUS is a new test that offers women an alternative to traditional Down syndrome screening methods during pregnancy. Unlike amniocentesis and chorionic villi sampling (CVS), which are invasive tests, MaterniT21™ PLUS is a simple blood test that is non-invasive to you and your baby, and includes SCA testing for sex chromosome aneuploidies.
The testing can detect Down syndrome and other chromosome abnormalities, including trisomy 18, 13, and sex chromosome abnormalities. It has a higher detection rate and a lower false-positive rate than first-trimester screening, which is the most common non-invasive screening test in pregnancy today.
A New Approach to Down Syndrome Testing
MaterniT21™ PLUS utilizes sequencing technology to identify DNA derived from fetal chromosomes. The technology is applied to the circulating cell-free DNA in maternal blood (i.e., fragments of DNA present in maternal blood that are not enclosed by a membrane). This DNA from chromosomes 13, 18, 21, X, and Y is quantified and when over or underrepresented, the likelihood of these chromosome abnormalities is significantly increased.
The detection rate for Down syndrome has been estimated to approach 99.1%, with a false-positive rate of less than 0.2%. The detection rate for trisomy 18 is over 99.9%, with a 0.28% false-positive rate. The detection rate for trisomy 13, based on a small study, is estimated to be 91.7%, with a 0.97% false-positive rate. Additionally, the lab testing for sex chromosome anomalies has a combined detection rate of 96.2% with a false-positive rate of 0.3%. These include Turner syndrome, Klinefelter syndrome, Triple X syndrome, and 47, XYY syndrome.
Who Can Utilize MaterniT21™ PLUS Testing with SCA Testing?
At this time, the technology has been recommended in a high-risk population, which includes:
- Women over the age of 35 at delivery
- Presence of an ultrasound finding
- A personal or family history of chromosome abnormalities
- Abnormal screening (e.g., first-trimester screening)
However, recent discussions among medical professionals have suggested that NIPT could be beneficial for all pregnant women, regardless of age or risk level. All testing decisions should be discussed with your doctor. Many prospective parents may feel nervous about the results of their test, but finding out about potential conditions early on can help you better prepare for the birth of your baby and what will come afterward.
How Accurate are Non-Invasive Prenatal Tests in NJ?
As mentioned above, non-invasive prenatal tests like MaterniT21™ PLUS are considered to be very accurate. These tests have a much higher detection rate than older screening methods and are less likely to result in a false positive. The lower false-positive rate gives expectant mothers extra reassurance that they will receive accurate test results that will shape their care for the remainder of their pregnancy. A negative result significantly reduces the risk of Down syndrome and other chromosome abnormalities, and therefore, reduces the number of unnecessary invasive tests like amniocentesis and CVS.