NT refers to the thickness of the nuchal translucency, which is usually below 2.5mm. If the test result is 2.8mm, further non-invasive DNA or amniocentesis is needed, and cardiac screening is also needed at around 24 weeks. Fetal nuchal translucency examination is usually performed at 11-13 weeks of pregnancy. If the result of the examination is within the normal range, it means that the risk of chromosomal abnormality in the fetus is low, and there is usually no need to be overly worried, and after that, you can carry out the routine examination to understand the normal development of the fetus. If the results of fetal nuchal translucency are abnormal, then further prenatal diagnosis is needed to clarify whether there is a possibility of chromosomal abnormality, viral infection, cardiac abnormality and so on. In case of abnormalities, it is recommended to go to the hospital for timely examination and standardized treatment under the advice of the doctor.