What is the normal NT value?

The normal range for NT value (nuchal translucency scan) is generally less than 2.5 mm. This standard is determined by B-ultrasound measurement of the thickest part of the fetal neck's subcutaneous anechoic translucent layer, and it serves as an important indicator for assessing whether the fetus may have chromosomal abnormalities or other malformations. Specifically, when the NT value is between 2.5 mm and 3.0 mm, it is referred to as borderline increased NT, which may indicate some risk for the fetus but does not necessarily mean there is a problem. However, if the NT value exceeds 3.0 mm, it is termed markedly increased NT, and the likelihood of fetal malformations significantly increases. It should be noted that NT values may vary as the fetus develops, and the normal range can differ across gestational ages. Therefore, NT examinations should be performed at the appropriate gestational age, and the results should be interpreted in conjunction with other tests and the physician's clinical judgment to comprehensively assess fetal health.