NT and Down’s syndrome are both highly accurate and are used to determine the health of the fetus, but the purpose, timing and precautions before the test are different, so it is not possible to accurately compare the accuracy rates. The NT scan is performed at 11-13 weeks of gestation, while the Down screening is performed at 16-20 weeks of pregnancy. During the NT scan, ultrasound is used not only to detect the thickness of the nuchal translucency layer, but also to diagnose and rule out serious anomalies such as cranial agenesis, anencephaly, single ventricle, single atrium, and umbilical bulge. In addition, it can be used to determine twin and multiple pregnancies, and also to determine the chorionic nature of the placenta by NT. In contrast, Down’s syndrome is a test that calculates the risk of having a fetus with congenital defects by testing maternal serum and taking into account the pregnant woman’s due date, age, weight and week of pregnancy at the time of blood collection. Both are different tests at different stages and by different means, and sometimes a combination of both tests is needed to make a judgment. If there is an abnormality in NT test or Down screening, it can be reviewed by DNA non-invasive or amniocentesis. Take care to keep your mood happy during pregnancy, don’t worry, and eat more protein-containing foods to enhance nutrition.