Non-Invasive Prenatal Genetic Testing

Blood TestGotta love prenatal testing.  The timing, the blood draws, the more invasive tests, the waiting, and – finally – the sometimes vague results.

At the time that I was pregnant, I had three fetal testing options available to me: Quad Testing, Amniocentesis, and Chorionic Villus Sampling (CVS).  I go into the details of each in my Prenatal Testing post, and the reasons why I selected CVS.  Basically, it was more diagnostic than quad testing, and could be conducted sooner than an Amnio (between 10 and 13 weeks of pregnancy vs. between 14 and 20 weeks of pregnancy).  The one aspect of the CVS test that gave me pause was the fact that it did and does carry a small risk of miscarriage.  Ultimately we decided to move forward with it, but spent an anxiety-ridden few days in bed post-test, hoping and praying that no miscarriage would result.

So I am delighted to hear about the new non-invasive prenatal genetic tests now available to pregnant women.  Finally expectant mothers can be empowered with knowledge – without any risk of complication.  Ease of administration, decreased costs, and available timing make them even more attractive.

Tests like Sequenom Center’s MaterniT21 PLUS (T21) and Integrated Genetics’ Harmony are up to 99% effective at detecting Trisomy 21 (Down Syndrome), 18 (Edwards Syndrome), and 13 (Patau Syndrome).  Performed around 10 weeks gestational age or later, these tests require a simple blood draw to analyze cell-free DNA in maternal blood for extra chromosomes.  While not technically considered diagnostic tests, they come pretty darn close; and any positive results could subsequently be confirmed with a true diagnostic such as CVS or Amnio.

Test results are typically returned within about 2 weeks, and costs of the tests appear to range from about $0 – $400 out of pocket after insurance (still significantly cheaper than either CVS or Amino – I am hearing $235 as a common copay).  An added bonus?  The test will also provide gender confirmation.

So what are the limitations?  Well, both CVS and Amnio test for a much larger array of potential disorders – these new blood tests just focus on some of the more common.  Also, these tests do not screen for open neural tube defects (only an Amnio will do that).  Some doctors remain skeptical about these new tests, and I’m told that not all offices will offer them.

But for parents without known genetic issues, I think they offer a very viable alternative to more invasive methods.  Much more accurate than traditional quad testing, these tests finally provide women a safe and relatively inexpensive option to better understand potential fetal risks.  I am all for these tests and only wish they had been available when I was pregnant.

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