Is it still necessary to do non-invasive test if the risk of Down syndrome is low?

During the pregnancy period, many pregnant women have carried out some examinations related to the health of the fetus, but it is relatively complicated for different fetal conditions. Usually, when some examination procedures show abnormalities, it puts too much pressure on us. So, does the low-risk Down syndrome screening also need to be minimally invasive?

In general, low-risk Down syndrome screening does not require minimally invasive surgery. If there is no genetic disease in the couple's family, and the pregnant woman is under 35 years old and has low risk, there is no need to perform further minimally invasive surgery; however, if there is no genetic disease in the couple's family, but the pregnant woman is over 35 years old, even if the risk is low, it is still necessary to perform further minimally invasive surgery.

1. If either of the couple's families has a genetic disease, it is necessary to further undergo minimally invasive testing even if the pregnant woman is under 35 years old and has a low risk of Down syndrome.

2. If either of the couple's families has a genetic disease, but the pregnant woman is over 35 years old, even if the Down syndrome screening is low risk, further minimally invasive testing should be performed.

3. If neither the husband nor the wife has any genetic disease, and the pregnant woman is under 35 years old, but has given birth to a Down syndrome baby, she should also undergo minimally invasive surgery.

In general, whether a low-risk Down syndrome screening test requires further minimally invasive treatment requires an in-depth analysis and decision based on individual circumstances.

Accuracy of Down syndrome screening

Down syndrome screening can detect 60-70% of Down syndrome patients. It needs to be made clear that the Down screening test can only help determine the chance of a fetus having Down syndrome, but it cannot confirm whether the fetus has Down syndrome. In other words, when the blood test index value is higher, the chance of having a Down baby is higher, but it does not mean that the fetus must have problems. It seems that older pregnant women over 35 years old have a higher chance of having Down babies, but it does not mean that their fetuses must have problems. On the other hand, even if the test indexes are normal, it cannot guarantee that the fetus will definitely not get sick.

Pregnant women whose Down syndrome screening index value is higher than normal 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.

With the continuous development of technology, in addition to Down syndrome screening, minimally invasive prenatal genetic testing for Down syndrome and chromosome 18 and 13 abnormalities can now be used. Minimally invasive prenatal genetic testing can detect more than 99% of Down syndrome patients. Like Down syndrome screening, the test can be performed by simply drawing blood from the arm, avoiding the increased risk of miscarriage caused by amniocentesis or CSF testing. For older pregnant women and those at high risk of Down syndrome screening, minimally invasive prenatal genetic testing is another new option for amniocentesis. For ordinary pregnant women, minimally invasive prenatal genetic testing can also be used as a better method for Down syndrome screening.