The Nuchal Translucency (NT) and Nasal Bone (NB) scan is a prenatal screening test used to assess the risk of certain chromosomal abnormalities, particularly trisomies like Down syndrome (Trisomy 21). During this ultrasound scan, healthcare Doctor measure the thickness of the nuchal fold (a space at the back of the baby’s neck) and evaluate the presence or absence of the fetal nasal bone.

An increased NT measurement and the absence or underdevelopment of the nasal bone can be associated with a higher risk of chromosomal abnormalities. However, it’s important to note that this is a screening test, not a diagnostic one. If the results indicate an increased risk, further diagnostic tests like chorionic villus sampling (CVS) or amniocentesis may be recommended to confirm or rule out these conditions.

The NT/NB scan is typically performed between 11 and 14 weeks of pregnancy and is part of a comprehensive assessment that considers other factors such as maternal age and blood test results to estimate the overall risk. It’s essential to discuss the results and any concerns with a healthcare provider to make informed decisions about further testing and care during pregnancy.