nuchal

The first trimester screening tests is also known as nuchal translucency screening, or NT, is a prenatal test that involves ultrasound and a blood test that can help determine the likelihood of having Down’s Syndrome or some other chromosome abnormality.

Over the last decade, new technology has improved the methods of detection of fetal abnormalities, including Down syndrome. Many but not all fetuses with Down syndrome have one or more so called 'markers' on ultrasound.