Nuchal Translucency

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Published on Friday, 16 September 2011 22:06

Written by Administrator

Nuchal Translucency

This is a test that is done to see if your baby has an elevated risk for having a chromosome problem. It is done between 1.5 and 13.5 weeks of pregnancy. The name comes form the nuchal fold in the baby’s neck that is measured. In this space between the skin and the tissue at the back of the neck fluid can build up. It is the depth of this fluid that is measured. At around the same time a blood test is done on the mother’s blood. Certain proteins in the blood are measured.

The results of the ultrasound and the mother’s blood results along with the mother’s age and weight are put into a program that will give an adjusted risk estimate for trisomy 21 (Down syndrome) and also trisomy 13 and 18. The results are given as anywhere between 1:5 or up to 1:5000 or more.

If the result is smaller than about 1:200 you are said to have a high risk of your baby having a chromosome problem. This test is not meant to be diagnostic. It will just give you a risk factor. There is no risk to the baby with this test. If you are said to have a high risk you will be referred to genetic counselling to discuss the results and also discuss further tests that will determine if your baby is affected.