The nuchal translucency scan is done between 11 and 14 weeks of pregnancy. It might need to be done alone, or it might be able to be done while youre having your dating scan.

When should nuchal scan be done?

The test is done between 11 and 14 weeks of pregnancy. It may be done as part of the first trimester screening test or the integrated screening test. This test shows the chance that a baby may have a certain problem.

Is nuchal scan necessary?

An NT scan is a safe, noninvasive test that doesnt cause any harm to you or your baby. Keep in mind that this first trimester screening is recommended, but its optional. Some women skip this particular test because they dont want to know their risk.

How accurate is a NT scan?

The accuracy of a screening test is based on how often the test correctly finds a birth defect. The nuchal translucency test correctly finds Down syndrome in 64 to 70 out of 100 fetuses who have it. It misses Down syndrome in 30 to 36 out of 100 fetuses.

What happens at your nuchal scan?

An NT is a special type of ultrasound using a very sensitive but safe machine. A sonographer will apply a transducer (wand) to the outside of your stomach to measure your baby from crown to rump and check that the fetal age is accurate. Then he or she will locate the nuchal fold and measure its thickness on the screen.

How common is thick nuchal fold?

According to the practice bulletin concerning fetal aneuploidy screening published by the American Congress of Obstetricians and Gynecologists, the likely ratio (LR) for thickened nuchal fold (TNF) is 11 to 18.6.