Should You Get Non-Invasive Prenatal Testing?

If you are a pregnant woman reading this, you are probably thinking that another ‘piece of advice’ about what you should and should not do, know, think, or feel is the last thing you need right now. After all, what you want to do is enjoy the glows and highs of being pregnant.

However, knowing about Non-Invasive Prenatal Testing (NIPT) may be one of the more responsible things to do at the beginning of your pregnancy. How terrible can it be? Given that pieces of your baby’s DNA circulate in your very own bloodstream, all you have to do is give blood, and doctors can find out about possible genetic issues of your baby pretty quickly and reliably. So, should you do it? Before saying either aye or nay, read some of the things below that may shed some light on the details and then decide for yourself. After all, like many other choices you make as a mom,this is immensely personal and intimate.

Let’s begin by underlining that a non-invasive prenatal test is considered a prenatal screening method. This means that it takes into consideration the cell-free fetal DNA from your baby’s placenta in a sample of your own blood in order to figure out whether you are at an increased risk of giving birth to a child that has a genetic disorder. In other words, a screening such as NIPT will not tell you for sure whether you will or will not give birth to a child with a chromosomal disorder. Rather, you will find out the likelihood of having that be the situation. So, now you may think what good is this? I find out about the chance of something being wrong with my baby. All it will do is worry me for the next eight months or so. Yes, you may be right. However, despite the fact that NIPT cannot tell you for sure what is going on with the genes of your baby, it is incredibly accurate. In fact, it can tell you the likelihood for three of the most common conditions (see below) with a whopping 97 to 99 percent accuracy.

Philosophically speaking, with such an accuracy, can’t a screening be called a test, you may wonder. That’s an interesting question. But before going further into the philosophy of why scientists call things certain ways, let’s continue going in the NIPT direction some more.

Once the results of NIPT are in, your physician and you can make more informed or educated decisions together. These include whether or not to do further, typically more invasive, diagnostic testing such as chorionic villus sampling or amniocentesis. These tests collect the amniotic fluid or placenta, and as such are based on the DNA of the baby. Now, these tests are TESTS. They can tell you for sure (100% certainty) whether or not your baby has that chromosome abnormality that the NIPT procedures suggested. When it comes to these last two tests, however, you’ll have to take the good with the bad: they are invasive (think poking your belly to get to some of the sampling material) and that means that they might increase your chances of losing your baby (having a miscarriage).

NIPT Testing Procedure

NIPT Testing Procedure

All you have to do is offer your arm at the physician’s office for a blood drawing. Your blood is then sent to a lab where technicians will analyze the cell-free DNA for signs of abnormalities. After you have received your results, your gynecologist will most likely want to pair the findings with additional ultrasound or nuchal translucency screening in order to decide whether or not you need more testing. It is recommended that a positive NIPT is almost always confirmed with either chorionic villus sampling or amniocenteses. These can concurrently also look for additional problems that the NIPTs cannot detect.

In addition to being able to pick up the baby’s blood type as well as gender, the NIPTs screen for three of the most common chromosomal disorders, including Trisomy 21 (Down Syndrome), Trisomy 18 (Edwards Syndrome) and Trisomy 13 (Patau Syndrome).

Different Kinds of NIPTs

There are currently four companies on the market that offer prenatal testing. These are Genesis Serenity, Harmony, Natera,and MaterniT21. They are essentially all the same. There are slight differences among the panels of genetic diseases that they screen for. For example, not all of them will screen for abnormalities such as triploidy and microdeletions. Furthermore, not all of them look at fetal cell-free DNA (some only consider the cell-free DNA from the mother), which means that they do differ when it comes to the accuracy of things. It would be best to consult with your gynecologist in regards to which of the four they prefer and stick to that.

When Is NIPT Done?

The benefit of the screening is that it can be done earlier than any other prenatal screening or diagnostic test. This means that it can be done any time after nine weeks into a pregnancy, which is pretty early. Just to compare, all other standard screenings are done later. Nuchal translucency is done between weeks 11 and 13, chorionic villus sampling is done at 10 to 13 weeks, the time range for amniocentesis is between weeks 16 and 18 and that for a quad screen is between weeks 14 and 22.

So, who Is NIPT for, really?

The American Congress of Obstetricians and Gynecologists still deem that NIPT needs additional evaluation in order to be considered ‘standard screening’ despite their accuracy and low rate of false alarms. However, the Congress does advise that all women discuss possible screening options with their doctors. This is different to what has been advised so far, namely that only women older than 35 and those with genetic disorders in their past (either among their children or among their family) get tested.

Given all this, there is no clear yes or no answer to whether or not you should get NIPT simply because the choice is deeply personal and intimate. However, whatever your preference may be, it certainly doesn’t hurt to know your options.

Laura Day
 

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