Noninvasive DNA:
Namely, non-invasive gene detection, non-invasive prenatal detection and non-invasive fetal chromosome aneuploidy detection. The most widely used technical name in the world is NIPT, which is defined by the Committee of American College of Obstetrics and Gynecology.
Non-invasive DNA is a method of prenatal screening and diagnosis using gene sequencing technology. It is only necessary to collect more than 5 ml of maternal peripheral venous blood and extract fetal free DNA fragments contained in maternal peripheral plasma. Through the new generation of Qualcomm DNA sequencing and biological information analysis, we can know the genetic information of the fetus and detect the risk rate of fetal chromosome aneuploidy.
The Code clearly stipulates that:
There are three main types of pregnant women who are suitable for non-invasive DNA prenatal testing:
The risk rate of Down syndrome in prenatal screening report11000 ≤1/270,11000 ≤18-trisomy syndrome ≤1/355.
Contraindications of interventional prenatal diagnosis such as threatened abortion, fever, bleeding tendency and unhealed infection during pregnancy.
Being in the first trimester (20 weeks +6 days) and just within the time for non-invasive DNA prenatal testing, I missed the best time for serological screening or the opportunity for prenatal diagnosis, but I have special requirements for reducing the risk of three chromosome diseases.
Compared with the applicable population, the effect of non-invasive DNA prenatal testing will be reduced to some extent. Beware of pregnant women:
Prenatal screening for high-risk and elderly pregnant women with expected delivery age ≥35 years old, and other direct prenatal diagnosis indications.
Pregnant with twins.
gestational age
Weight > 100 kg.
Pregnancy through in vitro fertilization-embryo transfer (IVF-ET).
Suffering from malignant tumor.
Finally, there are four special groups of pregnant women who are not suitable for non-invasive DNA prenatal testing, including:
One of the couples has a definite chromosomal abnormality, and the pregnant woman has experienced a fetal delivery with chromosomal abnormality.
Pregnant women who have received allogeneic blood transfusion, transplantation, cell therapy or immunotherapy within 1 year will interfere with the results of non-invasive DNA prenatal testing.
The results of fetal image screening such as B-ultrasound during pregnancy suspect that there may be chromosomal abnormalities in the fetus, such as microdeletion and microreplication syndrome.
High-risk groups of various genetic diseases.