What is the difference between noninvasive DNA and noninvasive DNA?

Tang screen is a relatively common clinical examination, can reflect the presence of fetal abnormalities, can be applied to the 15-20 weeks of pregnancy, its price is relatively cheap, the accuracy is relatively low, non-invasive DNA is applicable to the 12 weeks of pregnancy or so of the population, its price is relatively expensive, the accuracy is relatively high, can strengthen nutrition.