Nuchal translucency test
A measurement of the size of the translucent space behind the neck of the fetus using ultrasound at between 10 and 14 weeks of pregnancy, reflecting the amount of fluid that has accumulated under the skin of the fetus.
Nuchal translucency tends to be increased in chromosome disorders such as Turner syndrome and Down syndrome.
This is strictly a screening test.
It gives no concrete answers, only statistics.
Also called the nuchal fold scan.