Expectant mothers are required by doctors to undergo an NT screening ultrasound examination, also known as early Down syndrome screening, during 11-13 weeks of pregnancy. It is a blood test called "combined screening" that is performed at 15-18 weeks of pregnancy to detect whether the fetus may have Down syndrome, including a nuchal translucency scan of the fetus and a serum test with the pregnant woman. Both tests need to be done together with the nuchal translucency scan, and expectant mothers may have the question: is prenatal screening (early) combined with Down syndrome screening?
The answer is obvious: yes. Early Tang screening was able to detect the distance and thickness between skin and tissue cells. If the fetus has chromosomal abnormalities, then its cervical zona pellucida will be significantly thicker than that of a normal fetus. Especially for fetuses with Down syndrome. However, Down syndrome screening only detects the concentration of three substances in the serum of pregnant women, including chorionic gonadotropin, alpha fetoprotein, and free estriol concentration, and calculates the risk factor of fetal congenital defects based on various data of pregnant women at different stages.
Down syndrome, also known as congenital dementia, has an irregular onset and there is currently no cure for it. The above two tests are both used to check whether the fetus will have Down syndrome, but the accuracy cannot reach 100%, so sometimes a combination of the two tests is needed. Expectant mothers should never refuse the examination due to inconvenience or other reasons.
