Babies with certain genetic conditions have more fluid than normal, and the nuchal fold is thicker. An NT scan measures this fold to check for the risk of genetic conditions like: Down syndrome.

Of all the sonographic markers, any finding of a nuchal fold carried the highest LR for trisomy 21. A short humerus carried the second highest LR for Down syndrome. A short humerus was identified ...

Chromosomal abnormalities occur in 0.1% to 0.2% of live births, and the most common clinically significant aneuploidy among live-born infants is Down syndrome (trisomy 21). Other sonographically ...