There are also more people who have had NT at one time. Clinical cases of fetal malformations are after all a minority, so pregnant women with problems with NT are also a minority. However, this is a matter of probability, and specific to the individual still depends on the specific situation when the test is done. NT is an ultrasound measurement of the thickness of the fetal nuchal translucency at 11-13+6 weeks of pregnancy to determine the likelihood of fetal malformations. The measured value of <3.0mm is considered normal, and any value greater than or equal to 3.0mm is diagnosed as thickening of the nuchal translucency. The degree of thickening of the nuchal translucency is closely related to fetal anomalies. The more pronounced the thickening of the nuchal translucency, the higher the chance of fetal abnormality and the more severe the abnormality. If the NT value is abnormal, amniocentesis is needed to further rule out fetal anomalies. Pregnant women are advised to have regular checkups during pregnancy to detect abnormalities early and take the next step in diagnosis and treatment.