What You Need to Know About Nuchal Translucency Scans

A Nuchal Translucency Scan, also called an NT scan or nuchal scan, is a routine ultrasound screening exam, which helps physicians to identify your baby’s risk for chromosomal abnormalities.

An NT scan helps assess risk for:

  • Trisomy 21 (Down syndrome)
  • Trisomy 13 (Patau Syndrome)
  • Trisomy 18 (Edward Syndrome)
  • Major congenital heart defects

What to Expect

An NT scan is performed using ultrasound, a safe and painless exam that uses high-frequency sound waves to see inside the body, which is administered by a trained ultrasound technologist. After a clear gel is applied to your abdomen, the technologist will move a transducer, a microphone-shaped tool, over the gel until the baby is in the proper position. Then the technologist measures the clear (translucent) space in the tissue at the back of your baby’s neck. Babies with chromosomal abnormalities tend to accumulate more fluid at the back of the neck during the first trimester, causing this clear space to be larger than average.

How to Prepare

A nuchal translucency exam does not require much preparation however, it is important to have a full bladder. One hour before the exam, drink 32 oz. of water and do not empty your bladder. You’ll be able to empty your bladder as soon as your ultrasound exam is finished.


An NT scan provides an estimate of your baby’s risk for certain problems—it doesn’t provide a diagnosis. Based on the information from the NT scan, you can decide to have chorionic villus sampling (CVS) or amniocentesis, which can provide a diagnosis. CVS and amniocentesis are invasive exams, and while they are usually safe, they do carry risks including an increased risk of miscarriage.

Your Choice

All pregnant women should be offered this first trimester screening exam, but it is not mandatory. If you do choose to have a nuchal scan, which is harmless for mother and baby, visit the women’s imaging experts at Association of Alexandria Radiologists. Our welcoming and relaxing imaging facilities have the most advanced medical imaging equipment and a friendly and knowledgeable staff.