CVS, AFP and Amnio Tests

 

I’ve had a few questions about what these are, what they do, and why we chose to do the CVS, so to the best that I can, I shall try to explain these tests.

 

The most common test is the AFP (Alphafetoprotein) also called the “Triple Screen.”  This is a blood test given to moms between their 16^th and 18^th weeks of pregnancy.  It is a very common test because there are no risks to the baby, and it provides information about “markers” for particular special needs such as Downs Syndrome and spina bifida and something else--hence the "triple" screen.  Please check the link for more info. 

 

The scoop on this test is that it doesn’t tell you Yes or No as far as whether the baby has a special need.  It simply tells you whether there is a higher or lower probability of the baby having a special need.  It’s a “risk probability” test, not a definitive answer.  An additional problem for me is that at my age, the test has a high probability (around 25%) of a false positive—meaning that it would tell us that we have a problem when in fact we do not.  Once it tells you there’s a possibility of a problem, the doctor is likely to advise the woman to have an amnio.  So at my age, we wondered why we should bother having a test that’s likely to give us incorrect information and cause us to take another test anyway. 

 

The amnio or amniocentesis test is when the doctor sticks a big ass needle into the mom’s abdomen to withdraw some of the cells from the amniotic fluid.  This provides actual genetic and chromosomal information about special needs as opposed to the risk.  There is a chance of miscarriage with this test, usually around .3%.  Not 3% -- .3%.  It’s small, but it’s greater than 0.  This test occurs around 16 to 18 weeks.  So if women have an AFP which could indicate an issue, they quickly schedule an amnio.

 

We chose to have a CVS test.  It provides the same information as the amnio but the test occurs between weeks 10 and 12.  Yes, nearly 6 weeks earlier than the amnio.  A problem with the CVS test, however, is that the miscarriage rate for a CVS is higher---around .5% to 1%.  If the doctor has a lot of experience, the risk is near the low end---.5%.  The difference between .3 and .5% is not really different at that point.  In the CVS test, the doctor usually collects the “fingers” of the placenta through the cervix similarly to a pap smear.  However, on occasion, the doctor has to collect the cells through a big ass needle in the abdomen.  I’ve never known anyone to have to have the needle in this procedure.

 

As some folks who have commented lately have intimated, the CVS test is a bit more loaded than the other tests.  The reason is that if the news comes back negative, the news is early enough that the parents have more choices about what they will do with the pregnancy.  Many sources of information imply that the CVS test should only be used if the parents are open to abortion.  I don’t think that’s fair.  All of our friends who have taken the CVS have recommended it because of the earlier peace of mind that it provides. 

 

Dave and I chose to do this test for the main reason that it’s earlier than amnio.  That means we can either stop worrying earlier or we can start planning for a special needs baby earlier.  I like being prepared.  We have a good friend whose daughter has Down’s syndrome.  A Down’s child leads to a different path as parents, but we believe it’s a path we could take together if that’s the one given to us. 

 

I don’t think couples get pregnant with the intention of terminating the pregnancy if the baby isn’t “perfect.”  That said, I don’t think couples necessarily know how they are going to react when faced with tough situation.  I have a close friend who had to make a tough decision that rocked me to my core—because she and I have very similar beliefs and convictions and we had decided that although being pro-choice, we would choose to keep the baby.  I can’t and I don’t judge my friend.  What my friend’s decision did, though, was frighten me.  It brought home the fact that you cannot really anticipate how you’re going to react until you are actually in the situation. 

 

So that’s what we know and what we think about the different tests.  This is a very personal decision and I feel very vulnerable putting this out on the blog.  I am doing it because I hope it’s helpful to someone else. 

 

Good news:  I’m so glad we went for the CVS yesterday because we went for the regular OB visit today.  He tried to find the heartbeat, but couldn’t and didn’t try a lot because we’d gone for an ultra-sound yesterday.  He said it was a bit early for finding the heartbeat with a Doplar so I’m glad we saw bunny jumping around yesterday looking healthy.  Otherwise, I’d be near hysterical right now. 

 

11:43:30 AM