The Nuchal Translucency Test

What is a nuchal translucency test?
Nuchal translucency is a specialized ultrasound measurement of the narrow space between the neck of the embryo and the overlying skin. The information from this exam is combined with the size of the embryo, the age of the mother and other risk factors to establish a statistical risk for that particular pregnancy being complicated with Down's Syndrome and certain other chromosomal abnormalities. The results do not provide positive diagnosis for these defects. They only determine a statistical risk, and indicate whether further, more invasive testing is warranted.

How accurate is the test?
The nuchal translucency (NT) test (ultrasound measurement of NT alone) provides an 80% detection rate for Down's Syndrome. For comparison, the well-established "triple screen" only detects about 65% of Down's Syndrome. The Ultrascreen test involves the nuchal translucency measurement and blood tests from the mother, and increases the detection rate to over 90%.

The accuracy of nuchal translucency measurements is dependent on the skill and experience of the diagnostic center. The Fetal Medicine Foundation has certified a limited number of centers in 40 countries to perform nuchal translucency studies. Elite Diagnostics is proud to be the first in Florida to offer accredited nuchal translucency studies.

Who is a candidate for first trimester screening?
All pregnant women who are less than 35 years old, between 11 and 20 weeks of pregnancy, and who have no other high risk for chromosomal abnormalities are candidates for testing. The NT ultrasound measurement is normally done between 11 and 13 weeks.

Certain women over 35 may also choose to undergo this genetic screening, in order to avoid more invasive testing, but these women are offered definitive testing (amniocentesis or CVS) without this screening if desired.

What if my test shows an increased risk?
An increased risk does not mean a genetic disorder has been diagnosed. Follow up tests such as amniocentesis and chorionic villus sampling are then offered, which very accurately diagnose any chromosomal abnormalities.