Nerve translucency, or more precisely - the assessment of the nuchal translucency of the fetus - is one of the prenatal tests that allow to assess the risk of genetic defects of the fetus. Ultrasound with the assessment of the fetal nuchal translucency is recommended by the Polish Gynecological Society, which means that this examination should be performed by every woman expecting a child.

Translucency of the neck - what is it?

Cervical translucencyis one of the non-invasive prenatal tests, also known asfetal nuchal translucency assessment . This test allows the doctor to assess the reservoir of fluid in the neck of the fetus. On this basis, it is possible to precisely determine the risk of developing genetic defects of the fetus (Down's syndrome, Edwards syndrome, Patau's syndrome).

The study allows to identify as much as 75 percent. casesof Down's syndrome , and if the presence or absence of a nasal bone is also taken into account - up to 90%! Besides, it is a non-invasive test, which means that it is completely safe for a woman and a child.

What is the assessment of the nuchal translucency of the fetus, what are the indications for this test and when should it be done?

Neck translucency - when should this test be done?

The nuchal translucency assessment(NT) is performed during an ultrasound performed between the 11th and 14th week of pregnancy (up to the 13th week and 6th day of pregnancy to be exact) - when fetal parietal length (CRL) ranges from 45 to 84 mm. It is worth knowing that an earlier or later nuchal translucency assessment is unreliable.

The test should be performed by a properly trained doctor using high-class ultrasound equipment - measurements should be made with an accuracy of 0.1 mm! The nuchal translucency is assessed using the traditional 2D ultrasound technique. 3D or 4D ultrasound is not useful here.

Translucency of the neck - what is it?

Fetal translucency is assessed during the transabdominal ultrasound examination. During the examination, the gynecologist who performs them measures not only the nuchal translucency, but also the fetal parietal-seated length (CRL) and heart rate.

Based on these parameters and the age of the pregnant woman, the numerical risk of defects can be calculatedgenetic (if the doctor is certified by the Fetal Medicine Foundation according to the method of Prof. Kypros Nicolaides, the creator of this method). When it is not possible to quantify the risk of defects, the value of the nuchal translucency is given in mm.

Neck translucency - where to do, how much does it cost?

The nuchal translucency assessment can be done both in public institutions and in private clinics - in the latter, the examination usually costs from 150 to even 400 PLN. You do not need a referral to make the nuchal translucency. For pregnant women over 35, the examination is reimbursed (in facilities that have signed a contract with the National He alth Fund).

Neck translucency - what does the result say?

The risk of genetic defects is considered to be increased if it is above 1/300 (numerical risk assessment) or if the neck translucency exceeds 3 mm. However, an incorrect test result is not yet a verdict. It does not indicate fetal disease, but an increased risk of it - e.g. 70 percent of babies with a result between 3 and 4.5 mm develop normally!

Increased NT value can be verified by amniocentesis, which will exclude or confirm fetal chromosomal abnormalities (it is performed from the 15th to the 19th week of pregnancy.) If further tests do not confirm genetic defects, it is necessary to perform a cardiac echo and ultrasound of the fetus in the 20th week of pregnancy. Increased nuchal translucency is often associated with heart defects.