It has become the norm to test pregnant women for a host of abnormalities during pregnancy. The tests can help prepare a mother-to-be for having a child with special needs. They can also inform doctors and their patients when abnormalities are a threat to the mother and/or the fetus.
Noninvasive prenatal testing (otherwise known as NIPT) is a method used to screen a pregnant woman for chromosomal abnormalities in the child she is carrying. It was first introduced in Hong Kong in 2011 and was quickly put to use around the world, including in the United States.
Through noninvasive prenatal testing, doctors can determine whether the unborn child is at risk of having trisomy 13, trisomy 18 (Edward’s syndrome), Down syndrome, or an abnormality with a sex chromosome.
These tests are done with a blood test. Specialists are able to examine the fetal DNA in the blood of the mother to determine the risk of abnormalities. The child’s sex and blood type can also be determined.
There is no physical risk to the mother or the baby with this type of testing. They are performed during the first trimester and may give a woman the time needed to make an informed decision about carrying the pregnancy to term.
Noninvasive prenatal testing is generally only available to women with certain risk factors. Insurance may not cover this type of testing.
You may be a candidate for noninvasive genetic testing if:
1) You are at risk of having a baby with a chromosomal abnormality
If you have given birth to a child with a chromosomal abnormality in the past or if you are of advanced maternal age, then there is a higher risk for chromosomal abnormalities in your child.
2) You are a carrier of an X-linked recessive disorder
Some disorders generally only affect males such as Duchenne muscular dystrophy or hemophilia (which is a blood-clotting disorder). Noninvasive prenatal testing can determine the sex of the baby before an ultrasound can, though it will not determine whether the child has the disorder.
3) You have an Rh-negative blood type
This risk factor is typically not a concern during a first pregnancy but rather something you want to be aware of during subsequent pregnancies.
If the child you are carrying has an Rh-positive blood type (as determined by the noninvasive prenatal testing) and you have a Rh-negative blood type, then you might become sensitized with exposure to the baby’s red blood cells. You could produce Rh antibodies.
Since this type of testing is noninvasive, it might help some pregnant women avoid tests that could possibly present a risk to the pregnancy, such as amniocentesis and Chorionic villus sampling (CVS).
The possibility of this kind of prenatal testing should be discussed in detail by your doctor or genetic counselor to see if it has a benefit for you.
While most experts agree that there is no physical harm done to the mother or the unborn child with noninvasive prenatal testing, the test itself could make some women terminate their pregnancy without seeking further testing.
Natera, the maker of the Panorama-brand prenatal screening test, conducted a study that found that 22 women out of 356 (about 6 percent) terminated their pregnancies after learning their baby had a high-risk of an abnormality without confirming the results with more testing.
Noninvasive prenatal screening tests should not be seen as a diagnostic tool alone. Women should work with their health care provider to understand what the test does and does not conclude.
This will enable them to make the best possible decisions for themselves and their families.
Sources:
Mayoclinic.org. Web. 18 March 2015. ” Noninvasive prenatal testing.”
http://www.mayoclinic.org/tests-procedures/noninvasive-prenatal-testing/basics/definition/prc-20012964
Yahoo.com. Web. 14 December 2014. “Are faulty prenatal tests increasing abortions?”
https://www.yahoo.com/health/are-faulty-prenatal-tests-increasing-abortions-105361086337.html
Dovepress.com. 16 January 2015. “Non-invasive prenatal testing: A review of international implementation and challenges.”
http://www.dovepress.com/non-invasive-prenatal-testing-a-review-of-international-implementation-peer-reviewed-article-IJWH#
Reviewed March 20, 2015
by Michele Blacksberg RN
Edited by Jody Smith