Can NT detect fetal malformations?

For pregnant women, NT is a very necessary examination during pregnancy. Because the NT examination is a type of fetal malformation screening, it can provide a good understanding of the development of the fetus and determine whether the child has more serious problems such as malformations. Of course, the NT test can also determine whether the child has other problems. Next, I will introduce you to some relevant knowledge about NT examination!

1. What is NT?

NT (nuchal translucency) refers to the maximum thickness between the skin and subcutaneous soft tissue in the sagittal section of the fetal cervical spine. The NT test, also known as the nuchal translucency scan, is a method of measuring the thickest part of the subcutaneous echo-free transparent layer in the fetal neck by B-ultrasound. It is used to assess whether the fetus is likely to have Down syndrome.

If the NT value of a pregnant woman is detected to be outside the normal range during the NT test, further fetal abnormality screening tests should be performed, such as amniocentesis or chorionic villus sampling, to determine whether she has Down syndrome or other diseases.

2. What does NT check?

Babies with Down syndrome will have subcutaneous fluid accumulation, so the skin on the back of the neck will be thicker. If NT detects that the thickness of the fetal neck skin exceeds the standard value, it may be related to fetal chromosomal karyotype abnormalities and other structural malformations. The thicker the NT, the greater the probability of fetal structural abnormalities and chromosomal abnormalities.

In addition to detecting the risk of chromosomal abnormalities, thickening of the fetal nuchal translucency is also related to congenital heart disease.

If the NT test result exceeds the standard value range, pregnant women are advised to undergo follow-up fetal abnormality screening to further confirm the risk of fetal abnormalities so that timely countermeasures can be taken.

3. Necessity of NT examination

In our country, doctors generally recommend nuchal translucency scans for people at high risk of Down syndrome, such as pregnant women over 35 years old, those who have given birth to a baby with Down syndrome, or those with a family history of giving birth to a baby with Down syndrome. Although a nuchal translucency scan cannot determine definitively whether the fetus is infected, it can help pregnant women decide whether further diagnostic testing is needed.

The necessity of NT examination lies in that nuchal translucency scanning is a method to assess whether the fetus may have Down syndrome, which is a screening method. The NT test is different from diagnostic tests such as chorionic villus sampling or amniocentesis. They can provide a definite diagnosis, but the NT test can only indicate the risk.

The accuracy of the nuchal translucency examination is determined by many factors, including the level of the ultrasound physician and the accuracy of the scanner used, so the examination results cannot be guaranteed to be 100% accurate.

The NT test can only provide a reference for whether further prenatal diagnosis is needed. The ultrasound screening results cannot be used to determine whether the fetus is abnormal. To determine whether the fetus has chromosomal abnormalities, further chromosomal analysis is still required through chorionic villus sampling or amniocentesis.