Nuchal translucency test

Nuchal Translucency Test

Nuchal Translucency Test is a sonogram test used to assess the risk of a fetus having Down syndrome and other chromosomal abnormalities. It is usually done between weeks 11 and 14 of pregnancy. The test helps in finding out if the fetus has any structural problems. The test uses a combination of sonography and biochemistry to accurately measure the thickness of the fluid at the back of the fetal neck.


Patient should follow the instructions given by the doctor prior to the test. Drink 2-3 glasses of cold water half an hour before the appointment. This helps to fill up the bladder to get clear images. Avoid any kind of movement during the test as it might result in blurry images.


The procedure for the nuchal translucency test is simple. During an ultrasound examination, the pregnant woman will be asked to lie down wearing a hospital gown with her belly exposed. The doctor will then use a special sonographic transducer that releases sound waves and transmits the vibrations to a computer. This sound wave will create a picture of the inside of the abdomen and the fetus.

The doctor would then measure the thickness of the fluid at the back of the fetus's neck. This is known as the nuchal translucency measurement. The measurement should be taken within a specific time frame. After the measuremen t is complete, the doctor will record the measurements and determine if the fetus is at risk of having any chromosomal abnormalities. The doctor will then discuss the results with the pregnant woman.


Nuchal Translucency Test is primarily of two types, offered and accepted by doctors practicing obstetric ultrasound — Maternal Serum Screening Test (MSST) and Fetal Ultrasound. Maternal serum screening test is the traditional method for testing fetal nuchal translucency. It requires drawing a sample of the mother’s blood and screening it for any sign of Down syndrome or other chromosomal disorders. On the other hand, fetal ultrasound measures the fetal nuchal translucency directly. It’s not as invasive as the Maternal Serum Screening Test.


Nuchal Translucency Test is considered relatively safe as it is done externally and does not involve any kind of injectable material. However, there are few risks associated with this test such as misdiagnosing the thickness of the baby’s neck due to wrong measurements and wrong analysis of the sonography images. There is also a small risk of miscarriage due to the increased blood flow to the abdomen during the test.

Why This Test is done?

Nuchal Translucency Test is done to identify any potential chromosomal abnormalities in an unborn fetus. The test is highly effective in accurately measuring the thickening of the skin in the back of the fetus’s neck. The doctor can use the results from this test to decide if any further diagnosis or treatment may be needed.

When This Test is done?

Nuchal Translucency Test is usually done between 11 and 14 weeks of pregnancy. At this time frame the results are most accurate as the fetus’s neck is at its thinnest due to its growth. The test must be done before 19 weeks during a woman’s pregnancy as after this point the thickness of the neck will be too high and the results will be inaccurate.