What Is The Nuchal Translucency Scan, And What Do The Results Mean?

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If you’re between 11 and 14 weeks pregnant, your provider might offer a test called the nuchal translucency (NT) scan. It’s a simple ultrasound, but the information it gives can be very important.

This scan doesn’t diagnose a condition. Instead, it helps estimate the risk of certain chromosomal differences in your baby, including Down syndrome. It’s part of a broader group of tests often called “first-trimester screening.”

How the NT Scan Works

The NT scan looks at a small space at the back of your baby’s neck. All babies have a bit of fluid there during early development. The scan measures the thickness of this fluid, which is called the “nuchal translucency.”

Your baby needs to be in a specific position for the technician to take the measurement. You’ll lie on your back, just like with any standard ultrasound. The test is painless and usually takes about 15–20 minutes, though sometimes longer if your baby is moving around.

The measurement is very small—usually between 1 and 2.5 millimeters. That’s why the scan has to happen during a narrow window between 11 and 14 weeks. After that, the fluid naturally gets absorbed, and the test is no longer accurate.

What the Results Can Indicate

A thinner measurement is considered typical. A thicker measurement may signal a higher risk for certain conditions, especially when combined with other screening results, like blood tests. These conditions include Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13).

But a thicker NT reading does not mean your baby has one of these conditions. It only tells you that the chance may be higher than average. Some babies with thick measurements are born completely healthy. Others with very low measurements may still be diagnosed with a condition later.

Your provider will look at the NT result alongside your age, the baby’s crown-rump length, and hormone levels from your blood test. Together, these factors form a risk score.

This score is expressed as a ratio—such as 1 in 500 or 1 in 50. The smaller the second number, the higher the risk. For example, a result of 1 in 50 means there’s a higher chance than 1 in 500. But it’s still just a possibility, not a diagnosis.

What Happens If the NT Measurement Is High?

If your NT result is above the normal range, your provider may offer further testing. That could include non-invasive prenatal testing (NIPT), which looks at fetal DNA in your blood, or diagnostic options like chorionic villus sampling (CVS) or amniocentesis.

These follow-up tests give clearer answers. It’s your choice whether to have them. Some women want to know as much as possible. Others prefer to wait and see how things develop.

A higher NT measurement can also be linked to heart issues. If that’s a concern, your doctor may refer you for a more detailed scan of the baby’s heart later in pregnancy.

Understanding the Bigger Picture

The NT scan is just one piece of your baby’s health story. Many factors influence how your baby grows and develops. This scan provides valuable early information—but it’s not the final word.

Try not to panic if the result shows a higher risk. Many pregnancies go on to be completely normal after early concerns. Talk through your options with a provider you trust. Ask questions, and take time to process any information you receive.

Knowledge helps you make informed choices—but it doesn’t define your pregnancy. You’re still on a path full of possibility.