What does NT mainly check for the fetus?

There are many prenatal check-ups for pregnant women during pregnancy, and the NT test is one of the key tests. Many pregnant mothers have questions, what does the NT test for the fetus during pregnancy? NT is a new project for Down syndrome testing. It can effectively determine whether the fetus has Down syndrome. So when is the NT test usually done, the cost and common problems, I will explain it to you in detail.

What are the tests for the fetus during pregnancy?

nt, the nuchal translucency. Many people are not clear about what the NT test is. In fact, the NT test, also known as the nuchal translucency scanner, is a method of accurately measuring the location of the thickest echo-free transparent layer of the subcutaneous tissue in the fetus's neck through B-ultrasound. The measurement results are used to assess whether the fetus is likely to suffer from Down syndrome.

If the NT test result exceeds the index value range, it is recommended that the pregnant woman conduct subsequent fetal abnormality screening to further determine the risk of fetal abnormalities so that countermeasures can be taken as soon as possible.

The NT test is usually performed between 11 and 14 weeks of pregnancy. Some pregnant women want to do NT check before 11 weeks. In fact, it is technically difficult to do NT check before 11 weeks, because the fetus is still very small and generally cannot be found. After 14 weeks, the water stored in the fetus's subcutaneous tissue may be absorbed by the developing lymphatic system, making it impossible to obtain accurate test data.

The NT test needs to be done in a regular tertiary hospital or a large gynecological hospital, and the price is generally around 100-400 yuan.

In China, doctors generally recommend that key Down syndrome patients undergo a nuchal translucency scan, such as pregnant women over 35 years old, pregnant women who have previously given birth to a baby with Down syndrome, or pregnant women with a family history of giving birth to a baby with Down syndrome. Although the nuchal translucency scanner cannot accurately determine whether the fetus is sick, it can help pregnant women decide whether further diagnostic tests are needed. The nuchal translucency scanner is a way to assess whether the fetus is likely to have Down syndrome and is a screening method. NT tests are different from confirmatory tests such as chorionic villus aspiration biopsy or amniocentesis. They can provide a clear diagnosis, but NT tests can only indicate risks.

Does the thickening of NT mean that there is something wrong with the fetus?

nt means the thickness of the nuchal transparent layer, that is, the thickness of the fluid accumulation in the subcutaneous tissue behind the fetus' neck. Simply put, it is the thickness of the tissue fluid in the back of the neck.

Before 14 weeks, the fetus's lymphatic system has not fully developed, and the lymph nodes in the upper limbs will have temporary flow obstruction, accumulating in the cervical lymph sacs or lymph node blood vessels, forming a transparent layer on the neck.

By around 14 weeks, the upper and lower lymphatic vessels of the fetus are connected to the jugular sinus, and the transparent layer gradually softens and disappears.

Abnormalities in nt are mainly related to chromosomal abnormalities and serious malformations of non-sex chromosomes. Therefore, in the early and mid-pregnancy, NT can be used to screen whether the fetus has chromosomal abnormalities, spina bifida, cardiovascular and cerebrovascular malformations, and other abnormalities.

Expectant mothers may start to worry when they see the pregnancy test report. In fact, about 80%-90% of NT abnormalities will eventually turn out to be normal. In addition to looking at the standard value, the identification of NT abnormalities also requires the combination of pregnancy weeks and the age of the expectant mother. In the early pregnancy, the NT is thickened, which may become normal with the healthy development of the fetal lymphatic system. The probability of chromosomal abnormalities in older pregnant women will increase. Therefore, for expectant mothers over 35 years old, abnormal NT values ​​should be relaxed.