Nuchal Transluscency Ultrasonography
| What is the nuchal translucency screening test? This prenatal test (also called the NT or nuchal fold scan) can help your healthcare practitioner assess your baby's risk of having Down syndrome (DS) and some other chromosomal abnormalities as well as major congenital heart problems. The NT test is not invasive. It uses ultrasound to measure the clear (translucent) space in the tissue at the back of your developing baby's neck. Babies with abnormalities tend to accumulate more fluid at the back of their neck during the first trimester, causing this clear space to be larger than average. The NT scan must be done when you're between 11 and 14 weeks pregnant, because this is when the base of your baby's neck is still transparent. (The last day you can have it done is the day you turn 13 weeks and 6 days pregnant.) It's usually offered along with an evaluation for the presence or absence of nasal bone, as well as a blood test, in what's known as first-trimester combined screening. |
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