How is the NT scan performed in early pregnancy?
Aug 10, 2023
Source: Cainiu Health
Dr. Lv Aiming
Introduction
In general, the first-trimester NT (nuchal translucency) scan is an important indicator for assessing fetal structural abnormalities and chromosomal abnormalities. It involves using ultrasound to measure the thickness of the fluid-filled space at the back of the fetal neck, which is then compared to standard normal NT values. The first-trimester NT scan is typically performed between 12 and 14 weeks of gestation.
Generally, the NT (nuchal translucency) scan during early pregnancy is an important indicator for assessing whether the fetus has structural or chromosomal abnormalities. This test measures the thickness of the fluid-filled space at the back of the fetal neck using ultrasound and compares it with standard reference values. The specific details are as follows:
The NT scan is typically performed between 12 and 14 weeks of gestation. It involves using ultrasound to measure the thickness of the translucent layer at the back of the fetal neck. A specialized ultrasound probe is placed on the pregnant woman's abdomen to measure the thickness of this nuchal translucency and compare it with established normal ranges. Normally, the NT measurement should be less than 2.5 mm. If the NT value is between 2.5 mm and 3.0 mm, it is considered borderline thickening, and further testing such as non-invasive DNA testing (NIPT) and a detailed anomaly ultrasound are recommended. If the NT value exceeds 3.0 mm, it is classified as increased nuchal translucency. The greater the measurement, the higher the risk of chromosomal abnormalities such as Down syndrome. In such cases, amniocentesis should be promptly performed to confirm whether the fetus has chromosomal abnormalities.
In summary, the early pregnancy NT scan primarily assesses the thickness of the skin fold at the back of the fetal neck. If abnormal results are detected, it is essential to follow up with additional tests as advised by the physician.
