Can the visibility of the nasal bone in NT (nuchal translucency) screening exclude the possibility of Down syndrome?

NT usually refers to nuchal translucency in the fetus. In general, the visibility of the fetal nasal bone cannot completely rule out Down syndrome. Nuchal translucency screening is a risk assessment tool, not a diagnostic method. If any physical discomfort occurs, it is recommended to seek medical attention promptly and follow medical advice for treatment. The detailed explanation is as follows:

During nuchal translucency screening, if the fetal nasal bone is clearly visible, this is generally considered a positive sign. One common feature in fetuses with Down syndrome is an absent or underdeveloped nasal bone. Therefore, if the nuchal translucency scan shows a complete and clearly visible nasal bone, the risk of Down syndrome appears relatively low based on this single indicator. However, this does not entirely exclude the possibility of Down syndrome. To more accurately determine whether the fetus has Down syndrome, doctors may recommend further diagnostic tests such as amniocentesis or chorionic villus sampling (CVS), which can provide definitive diagnostic information. The final decision should be based on a comprehensive medical evaluation and counseling, including detailed genetic counseling and necessary diagnostic testing.

Pregnant women should undergo regular prenatal check-ups during pregnancy and follow their doctor’s recommendations for any necessary additional tests to ensure fetal health.