Wednesday, October 10, 2012

Genetic Testing: To Test Or Not To Test?

If you ever sit down and talk with a pregnant women chances are they'll have an opinion on doing genetic testing. Almost, (if not all) doctors offer it when you first find out you're pregnant.

First off, lets have a little genetic lesson. We get a gene from our mom and a gene from our dad, to make 23 pairs. So mom gives you one chromosome 1 and dad gives you one chromosome 1. This makes YOU!
Do you remember R r? Dominant vs. Recessive? A Dominant gene is the R, this is the one that shows. r is recessive meaning you don't see it IN LESS both parents give you a "r." An example of a recessive gene is blue eyes. This means this person has rr. Brown eyes is dominant, so you have RR OR Rr. This is a very very basics of genetics, it gets far more complicated than I can go into.

So what does this all this mean when you're pregnant?

Well you've passed on your genes! And the big question is:

"Do I carry a mutation? Could it lead to a different life for my baby?"


A mutation according to the NIH (National Institute of Health) "A gene mutation is a permanent change in the DNA sequence that makes up a gene. Mutations range in size from a single DNA building block (DNA base) to a large segment of a chromosome."

Some examples of genetic mutations are Fragile X, Downs Syndrome, Tay-sachs, Cystic Fibrosis, and Sickle Cell Anemia.

So how do they test for these?

There are several different ways.
First, a simple blood test. Since they baby uses your body as a filter it's blood can be found in yours. So they'll take  blood sample. They can not get a 100% reading from it, but they can get a good guess.
For you as a parent to see what you're a carrier for it's a simple blood test.

Second, an ultra sound! With the use of blood tests and measurements of the baby they can determine if there is any physical defects that go along with a genetic disorder. Such as Downs Syndrome, the typical facial features of a person with this disorder can be looked at by the size and shape of the nose, (pretty cool.)

Third, CVS (Chronic Villi Screening). I never heard of this one till I got pregnant. And having no experience with it I'm going to take what The Genetics and IVF Institute has to say:
"CVS is a specialized alternative test to amniocentesis. It involves removing a small amount of tissue called the chorionic villi, which is located on the outside of the fetal gestational sac and will later become the placenta. The chorion is a fetal tissue, and shares its genetic makeup with the fetus, not the mother. The chorion has many small, finger-like projections on its outer surface, and a few of these may easily be removed without disturbing the pregnancy. The chorionic villi cells may be used for chromosome analysis or other genetic testing. The chorionic villi cannot be used to test for open neural tube defects. CVS is performed 10.5 weeks to 14 weeks." - Genetics and IVF Institute of Northern VA

And lastly, and the one most people think of is an Amniocentesis. This is the only 100% (ok really 99.5%), way to know what is the genetic make up of you're baby. This is the "scary" one. There is a slight risk to the baby. 1:200 have chance of miscarrying around 15 weeks, and around 23 weeks the odds are better at 1:400. Several places that specialize in genetic testing have their own rate of miscarriage.  It can be performed 15.5 weeks- 23 weeks. And later to determine lung development. Genetics and IVF  Institute explains what an Amniocentesis is:

"During an amniocentesis a small amount (usually 2 tablespoons) of amniotic fluid that surrounds the fetus is removed. The amniotic fluid contains cells that have been shed by the fetus during normal development. These cells may then be used for chromosome tests and/or specific genetic tests. The fluid itself is tested for the level of alpha feto-protein (AFP) or for biochemical genetic disorders, if appropriate.

Amniocentesis is typically available at GIVF from 15.5 to 22.9 weeks of pregnancy.  The amniocentesis procedure involves guiding a thin needle through the mother’s abdomen and into the amniotic sac (see figure below). Ultrasound is used to determine the location of the fetus and the best place to withdraw the fluid.  The entire procedure is done under ultrasound guidance." - Genetics and IVF Institute of Northern VA.

And this leads to the BIGGER question:

"Do I want to know?"

Do you want to know if you're precious baby is going to be sick before they are born?

Many say no. That it doesn't matter, it's something they'll deal with when the baby comes and that's that. Why worry the entire pregnancy? Or they want to have a family and only if there is something wrong with the first born will they get tested. Why Worry?

But there the few that say yes. It's just a blood test. I want to be able to prepare (financially, physically, emotionally, spiritually) if needed. If my baby needs medical attention when they're born I want to be at the right place and have the right doctors there. What if my baby dies because they couldn't get the medical attention fast enough? If I have a higher risk of having a child with *** genetic disorder, then my partner and I need to discuss our family options.

My sixth grade teacher had us memorize a phrase that I respond with when asked my take on the issue:

"Knowledge is power,
Grab it while you can."

For some it's a matter of money. Not all insurances will cover genetic testing. Then you need to decide is it worth the money? And they're not always cheap.

There are free genetic testing clinics offered around the country at different times of the year. 

Troy and I have different opinions on this subject. And it comes up every single time I mention a doctors appointment. Even though I've had all the blood tests offered its still something we'll bud heads on.

Genetic testing does not answer all the questions an expectant mom can have. In fact many babies will be genetically fine be born with a syndrome, etc. But it can eliminate the worry, especially if you and or your partner are carriers.

*Genetic testing should never be used as a way to decided if the baby should be aborted or not.*


  1. I don't do genetic testing, because the error rate is too high. For example, I went through literal hell with Joseph, because his test came back as likely Trisomy 18. I am a mom who would like to know ahead of time, but I absolutely do not think an amnio is worth the risk. And blood testing really isn't that reliable.

    With ultrasound today there are many things that can be clearly seen. The technology is incredible. I think the blood test causes more worry and what ifs than it is worth. Also, don't discount mothers intuition...sometimes you just have to trust what God tells you, or what your gut tells you.

    Great post, by the way. You have really done your research! I learned some new things today!

  2. And that's ok!!! This was more informative than anything, I learned a lot, and as I was talking to other mom's I realized that many people really don't know what is out there. I grilled my doctor about my options because I wanted to know! But I really didn't want to do an amniocentesis, (Troy and I have agreed only if something comes up hinky will it be considered.)

  3. I really appreciate all your research!

  4. Wow, that was great, Julia! Thanks for the info. I have definitely learned something from reading your research here. :) Also, well put!