“NT is the thickness of the nuchal translucency, an important indicator for early Down’s syndrome screening.NT measures the thickness of the fluid layer in the subcutaneous tissue of the nuchal region of the fetus and evaluates whether the fetus is at risk for Down’s syndrome, congenital heart disease, etc. The NT test does not examine the fetal nasal bone. However, the NT test is measured by ultrasound, and the development of the rest of the fetus is observed during the ultrasound. “If the nasal bone is visible during the ultrasound examination, the fetal nasal bone is visible, and this alone is a normal test result. Whether the NT result is normal or not needs to be analyzed in conjunction with the NT measurement.