What is required for free Down syndrome screening

Now there is a technology that can detect children with Down syndrome. It can detect it during the fetal process. This is the common Down syndrome screening. Although Down syndrome screening has been gradually promoted, there are still many people who are unwilling to accept it. They think that this examination is unnecessary. Therefore, everyone has launched free Down syndrome screening. What needs to be checked during this process?

What is Down syndrome screening?

Down syndrome screening is the abbreviation for prenatal screening test for Down syndrome. The purpose is to test the blood of pregnant women to detect the concentrations of alpha-fetoprotein, human chorionic gonadotropin and free estriol in the maternal serum, and to determine the risk factor of the fetus suffering from congenital idiocy and neural tube defects based on the age, weight and gestational age of the pregnant woman.

When is Down syndrome screening done?

When is the best time to do Down syndrome screening? The best time to do Down syndrome screening is 15-20 weeks of pregnancy. Doctors recommend that Down syndrome screening should be done at 15 to 20 weeks, but the conditions of each examination hospital are different, so please wait for the hospital to notify you of the specific time for Down syndrome screening. At this stage, the possibility of congenital idiocy can be predicted through examination. The main purpose of Down syndrome screening is to avoid the risk of congenital idiocy in the fetus to a certain extent.

1. Down syndrome screening is a possibility test: the high-risk group only means that the fetus is more likely to be a child with Down syndrome, and the low-risk group may also have Down syndrome.

2. About 1/10 of all pregnant women are high-risk groups, and 1-2/100 of the high-risk groups are Down syndrome babies, which means that 1-2/1000 pregnant women are Down syndrome babies.

3. When the blood test screening value is greater than 1/270, it means you are in a high-risk group, and the normal value is around 1/700. The international standard is 1/2704, and the Down syndrome screening value is a revised value.

The factors that affect the Down syndrome screening value mainly include: pregnant woman’s age, gestational age, fetoprotein secreted by the fetus, human chorionic hormone secreted by the placenta, drug factors, genetic factors, etc. Taking Dolly Mam to protect the fetus may cause human chorionic gonadotropin to exceed normal values, which may affect the Down syndrome screening value. Down syndrome screening can detect 60-70% of children with Down syndrome.

It should be made clear that the Down syndrome screening test can only help determine the chance that the fetus has Down syndrome, but it cannot determine whether the fetus has Down syndrome. That is to say, when the blood test index is high, the chance of having a baby with Down syndrome is higher, but it does not mean that there must be something wrong with the fetus. Just as older pregnant women over 35 years old have a higher chance of having Down syndrome babies, it does not mean that their fetuses will definitely have problems.

On the other hand, even if the test index is normal, it cannot guarantee that the fetus will not be sick. Pregnant women whose Down syndrome screening index exceeds the normal level should undergo amniocentesis or chorionic villus sampling. Only if the results of amniocentesis or chorionic villus sampling are normal can the possibility of Down syndrome be 100% ruled out.