The best time for pregnant women to do non-invasive DNA

There are many prenatal check-ups, including non-invasive DNA, gynecological B-ultrasound, Down syndrome screening, etc. These methods can be used to detect whether the fetus has any deformities. Take non-invasive DNA as an example. It must be tested at the right time to achieve good results. When is the best time for pregnant women to do non-invasive DNA testing?

The best time for pregnant women to do non-invasive DNA

The best pregnancy week for non-invasive DNA testing is 12-24 weeks. The range of gestational weeks for non-invasive fetal DNA testing is very wide. If the test is performed when the gestational week is less than 12 weeks, the fetal DNA concentration in the peripheral blood will be too low to meet the testing requirements. If the test is performed after 24 weeks, if the test result is poor and an abortion is required, it will cause greater physical harm to the pregnant mother.

Non- invasive DNA testing key content:

1. No need to fast before testing:

It is not necessary to be on an empty stomach when doing minimally invasive fetal health testing during pregnancy. Expectant mothers only need to ensure a normal diet.

2. Pay attention to the inspection time:

The best time for minimally invasive fetal health testing during pregnancy is between 12 and 26 weeks of pregnancy. It must be done within this time frame, so as not to affect the inspection results, and the inspection accuracy is extremely high within this time frame.

3. Minimally invasive fetal health examination during pregnancy is not equivalent to Down syndrome screening:

Minimally invasive fetal health testing during pregnancy mainly tests the three pairs of sex chromosomes of the fetus: 21 (Down syndrome), 18 (Maria syndrome), and 13 (Patau syndrome). Therefore, when expectant mothers undergo minimally invasive examinations, they must insist on completing all examination items to ensure the health of the fetus in all aspects.

New item of prenatal checkup: non-invasive DNA is suitable for the following groups

Scope of application: 1. In the prenatal diagnosis report, the risk rate of Down syndrome is 1/1000≤1/270, the risk rate of 18-trisomy syndrome is 1/1000≤1/350, and the risk rate of 13-trisomy syndrome is 1/1000≤1/350, that is, serological screening and imaging diagnostic tests show that common chromosomal aneuploidy is close to high risk. 2. During pregnancy, there are contraindications to invasive prenatal examinations such as threatened miscarriage, fever, bleeding tendency, and unresolved infection. 3. The baby is in the longest gestational age (more than 20 weeks and 6 days of pregnancy) and happens to be within the period when minimally invasive DNA prenatal testing can be performed. The baby has missed the best time for serological screening or the opportunity for prenatal examination, but has special requirements for reducing the risk of the three major sex chromosome diseases.

Groups to use with caution: 1. Pregnant women with high risk of prenatal diagnosis, older pregnant women aged ≥ 35 years, and other conditions for timely prenatal examinations. 2. Holding twin babies. 3. Pregnancy weeks < 12 weeks. 4. Weight>100KG. 5. Get pregnant through the in vitro fertilization-test tube transfer (IVF-ET) method. 6. Suffering from combined malignant tumors.

Groups prohibited from using: 1. One of the spouses has confirmed chromosomal abnormalities, and the pregnant woman has given birth to a fetus with chromosomal abnormalities. 2. If the pregnant woman has received allogeneic intravenous injection, transplantation, cell therapy or immunotherapy within 1 year, it will affect the results of minimally invasive DNA prenatal testing. 3. During pregnancy, the results of fetal imaging diagnosis and screening such as B-ultrasound suggest that the fetus may have chromosomal abnormalities, such as micro-deletion and micro-duplication syndrome. 4. High-risk groups for various genetic diseases.