Source: Video and Images Created by Amanda Soderlind
Welcome to this lesson today on detecting birth defects.
Today we will be looking at various methods that are used in order to detect birth defects in an unborn fetus. Now days we have lots of different types of technologies that help us detect these birth defects in an unborn fetus, and the three we're going to be talking about today are listed on the screen here.
We're going to start by talking about chorionic villus sampling, also sometimes abbreviated as CVS. Chorionic villus sampling is a sampling that can be used to detect for birth defects as early as the eighth week of pregnancy. And basically what happens with this type of sampling is, a tube that has a suction end is inserted into the vagina, up into the uterus, and then will suck out a small sampling of chorionic villus cells. These cells are part of the placenta, which will then be tested for any birth defects at that time.
The next type of way that we can test for birth defects is with amniocentesis. With this type of technology, it can be used between the 14th and the 16th week of pregnancy. It's testing the amniotic fluid. It's testing the amniotic fluid that the fetus is in during pregnancy. This amniotic fluid contains sloughed off cells of the fetus. And if you take a sample of that amniotic fluid, they can test some of those sloughed off cells for any types of birth defects. So basically what happens is that a needle is inserted into the mother's belly, and then into that amniotic fluid. And then some of it is pulled out and then tested. So this is one way that can be used in order to test for these birth defects, by using the cells of the fetus that are found in the amniotic fluid.
And preimplantation diagnosis is another way we can test for birth defects. This type of diagnosis actually is involved with in vitro fertilization. It's screening of an embryo that has not yet been implanted into the uterus. So that's why we're talking about preimplantation. It happens usually around the eight cell stage of development. They will take one of those cells, test it for any birth defects, and if it comes out clear, they will then implant that embryo into the mother's uterus. So it's screening the embryo conceived by in vitro fertilization for these genetic defects before it has been implanted into the uterus. So preimplantation.
As with all of these different types of ways to detect birth defects, there are definitely some benefits associated with it. A parent would know in advance if their unborn child has any sort of birth defects, and they could prepare themselves for that. But it also has some risks associated with it, as well. Some types of ways to birth defects, especially with amniocentesis since it is a little bit more invasive, can lead, rarely, but sometimes can lead to infections, and things like that. And with the chorionic villus sampling, one of the risks associated with that is that the child can end up with an abnormal number of fingers and toes, because of that process. So there definitely are some risks and benefits associated with it that the parent would have to weigh before going through with any of these types of technologies.
This lesson has been an overview on detecting birth defects.