Early Down’s screening Early pregnancy Down’s screening is a combination of ultrasound and serum biochemistry results from fetal nuchal translucency (NT) screening to assess a pregnant mother’s risk of conceiving a fetus with a chromosomal genetic disorder. Early Down’s screening can detect a fairly high percentage of Down’s syndrome and other chromosomal abnormalities, but there are still some drawbacks to early pregnancy Down’s screening because the accuracy of the posterior nuchal translucency scan is determined by many factors, including the level of the ultrasonographer and the accuracy of the scanner used. If you do not pass the early Down’s screening, you can do nothing or have diagnostic tests, such as an amniocentesis, to confirm the diagnosis in more detail.