Nuchal Translucency – What are Normal Values?

Among the tests that all babies must pass is nuchal translucency. Know what is and what the normal values ​​of nuchal translucency.

Nuchal Translucency - What are Normal Values?

When a woman becomes pregnant, she needs, during the nine months of gestation, to undergo several tests to diagnose possible problems in her, and especially in the baby.

This test was created because fetuses with malformations or genetic diseases accumulate fluid in the back of the neck.

In this examination an increased measure means risks to the fetus.

What is nuchal translucency

Nuchal translucency (TN) is an examination done by ultrasonography .

In fact it is a measurement done in the region of the nape of the fetus.

This measure helps to calculate the risk of the fetus having some diseases, such as Down Syndrome and congenital heart disease.

Nuchal translucency needs to be done when the fetus is between 45 and 84 mm in length, measuring from the head to the buttocks.

This in time of pregnancy is equivalent to 11 to 14 weeks of gestation. Always before this time.

In fact, nuchal translucency is not an examination to make a diagnosis; it only defines which group has low or high risk.

To be sure that a fetus has Down Syndrome, a biopsy of chorionic villi or amniocentesis is required.

Nuchal translucency began to be made in large hospitals in the 1990s. The measurement should be made following the Fetal Medicine Foundation measurement standards.

Normal values ​​of nuchal translucency

Values ​​below 2.5 mm are normal, but specialists may use other parameters besides nuchal translucency.

In these cases, the results are represented numerically as a percentage.

This test is 80-90% effective, but to make sure the fetus is sick or healthy, you need to do other tests.

Advantage of nuchal translucency examination

The advantage of measuring the size of the nape of the fetus is to be within the risk of your baby having Down Syndrome.

Years ago, the biggest risk factor for having this disease was the age of the mother. When the pregnant woman was 35 years old or older, the risk was higher.

How the measurement is made

The examination can be done in two ways.

The first one is doing a normal obstetrical examination, where the measurement will be made through the ultrasound.

The second one is performing a first trimester morphological examination, in which the data of the common examination are considered. The age of the mother and the history of the previous children with Down syndrome.

Therefore, the nuchal translucency is a measurement made at the nape of the fetus to see if the size is normal or larger.

If the neck is above normal, the baby may have Down Syndrome or some congenital disease.