The NT test is a screening test for Down’s syndrome and congenital heart abnormalities that is performed early in pregnancy to detect the thickness of the nuchal translucency membrane. Therefore, even if the NT test is normal, prenatal checkups are required on a regular basis. The non-invasive DNA test is performed by the mother’s blood to detect fetal DNA, and the results are more accurate. The results of both tests are generally based on non-invasive DNA. To rule out congenital heart development abnormalities, a 4D ultrasound is required, and its results are also more accurate.