You may be wondering what nuchal translucency is. It is a fluids’ collection under the skin of the baby’s neck. It can be measured during the second trimester with the help of an ultrasound. All the babies have fluid but the babies with Down syndrome have more of it.
What is the nuchal translucency scan?
This is a test meant to determine the chances of your baby being affected by Down syndrome. This test can only assess the risks. In order to have an accurate diagnosis there is need for another kind of test, such as amniocentesis or CVS that come with a higher risk of miscarriage.
How is the scan for nuchal translucency performed?
In order to have the test you must have an ultrasound between the 11th and 13th week of pregnancy. Before this period the baby is too small for the fluid to be visible. On the other hand if you have the ultrasound too late, the excess fluid could be absorbed by the organism of the baby.
In the majority of the cases the NT scan is performed through the belly, but in some special cases there might be need for a vaginal screening. This way the doctor will be able to get a better look at the baby.
The screening has no risks for the baby and it shouldn’t be uncomfortable for the mother either.
In order to be sure of the gestational age, the sonographer during the nuchal translucency test will measure the baby from top to the bottom of the spine. Then the width of the NT will also be measured.
The skin appears as a white line and the fluid will have a black color on the screen.
The good news about the test for nuchal translucency is that during it the parents can see the baby to the smallest details. The scan can be used to exclude some of the major abnormalities. However it is best to have a detailed anomaly scan as well after the 20th week of pregnancy.
Normal results regarding the nuchal translucency
During the 11th week of pregnancy, it is normal for the NT to be of 2 mm. During the 13th week this could be of 2.8 mm. This is because the NT grows as the baby develops. Nonetheless it is possible to have more NT and for the baby to turn out to be entirely healthy and normal.
As the results of the NT test increase, the chances for the baby to be affected by the syndrome also increase. It is also possible for the little one to be affected by other chromosomal abnormalities. The good news is that only a few babies have high results on these scans.
How is the risk calculated?
It is a known fact regarding the test of NT that all women could give birth to babies with Down syndrome. The chances increase with age.
Now you know more about the NT scan and you know how important it is.