Do we have to do non-invasive DNA?

With the popularization of medical knowledge, pregnant women's acceptance of noninvasive DNA is getting higher and higher. Clinically, some pregnant women directly request non-invasive DNA testing in the second trimester, instead of Down's screening. I believe many pregnant women have such doubts. Is it okay to do this?

First of all, what is noninvasive DNA?

Maternal peripheral blood during pregnancy contains free DNA, almost all of which comes from placental trophoblast cells. Therefore, the technical basis of noninvasive DNA is to detect the free placental DNA in the peripheral blood of pregnant women. Generally, it can be detected after 4 weeks of pregnancy, and the content rises and can exist stably after 8 weeks of pregnancy.

Applicable diseases

According to the current level of technological development, the main applicable diseases are three common chromosomal aneuploidy abnormalities, 2 1- trisomy, 18- trisomy and 13- trisomy.

Applicable time

Non-invasive DNA testing should be carried out after 12 weeks of pregnancy, and the suitable gestational age is between 12 weeks and 23 weeks of pregnancy.

Applicable people

Unsuitable crowd

Remind the mothers to pay attention:

We all know that the accuracy and specificity of Tang screening are relatively low, and the accuracy of non-invasive DNA is significantly higher than that of Tang screening, but Tang screening includes the detection of open neural tube defects, while non-invasive DNA does not, so pregnant women who directly carry out non-invasive DNA should strengthen the ultrasonic examination of neural tube defects in the second trimester.

Although the accuracy of noninvasive DNA is high, it is still a means of prenatal screening, not a means of prenatal diagnosis. If there is any inappropriate non-invasive DNA, prenatal diagnosis must be made according to the doctor's advice, and don't be afraid that prenatal diagnosis will miss the opportunity to diagnose the disease.

I'm happy to answer your question. First of all, I am a mother-to-be. I've done noninvasive DNA. First of all, non-invasive DNA is to check three chromosomes to see if there is a high risk. In the vernacular, it means to see if the fetus is good. In the past, we usually screened for Down's syndrome. Similarly, we also checked whether the fetus was good or not and whether it was a fool. Now the non-invasive DNA has been upgraded, which is more accurate. Doctors usually ask you, is it direct noninvasive DNA? Or the traditional Tang sieve? So let's talk about it here. If the traditional Tang sieve test results are unqualified, it is also a high risk. Then the doctor will ask you to do further noninvasive DNA. If non-invasive DNA passes, rest assured, because non-invasive is more authoritative. If Downs successfully passes, the doctor won't say much, that is, there is no need for noninvasive. Then I choose noninvasive DNA directly, and choose noninvasive DNA to save trouble. Now there are two generations of non-invasive DNA, that is, checking more chromosomes, so I won't say much here. The nature is the same, but the price is of course more expensive, 1000, the first generation 1800-2500.

Secondly, some pregnant women encounter some problems in prenatal examination, such as large-scale abnormal examination showing strong echo or strong light in fetal heart. Then the doctor will ask for further noninvasive DNA for further investigation. Therefore, if there are some problems during pregnancy, most of them need further non-invasive DNA screening. Its role should not be underestimated. Of course, pregnant mothers who have bright green labels all the way don't do it, and of course there is no visit.

By the way, there is also non-invasive DNA in sheep puncture, which can be said to be confirmed. Non-invasive means that the risk level will not be confirmed in a certain sense, but now most doctors use non-invasive DNA to infer that there is no problem in sheep puncture. The doctor won't do it. It's too dangerous.

I hope my answer is helpful to you.

Before answering this question, we need to know what non-invasive DNA is. The simple point is to extract maternal blood and understand fetal chromosomes. The main items of common non-invasive DNA examination are 18- trisomy, 13- trisomy and 2 1 trisomy. Enhanced non-invasive DNA testing has more items.

So is it necessary to do non-invasive DNA testing? Of course, non-invasive DNA testing is not necessary. Need 1000 yuan or more, or even 2000-3000 yuan, is not in line with China's national conditions, and not everyone can afford it. At present, Down's screening is compulsory in China, and non-invasive DNA testing is an alternative project. Of course, you can choose if you have conditions. We just chose non-invasive DNA testing, not for anything else, because I am not particularly optimistic about Down's screening, and the detection rate is too low, so I chose non-invasive DNA testing. In Shaoxing, the non-invasive DNA test was 1000, but he compared it with 265400. Because of this, I think we are still worth spending.

Although the detection rate of non-invasive DNA examination is high, it is only a screening method, not a prenatal diagnosis, and treasure mothers can't blindly follow it. When there is prenatal diagnosis, they must have amniocentesis.

To sum up, non-invasive DNA testing is not a mandatory item, but you can choose non-invasive DNA testing if you have the conditions. After all, non-invasive DNA testing is better than Tang screening. Good luck with your pregnancy.

To understand this problem, in fact, the subject should first understand what the purpose of this inspection is and what inspections have similar guiding significance?

Noninvasive DNA detection-13 trisomy, 18 trisomy and 2 1 trisomy syndrome has a diagnostic rate as high as 99%, so it has been widely used in clinic.

Similarly, Down's screening, divided into Down's screening in early pregnancy and Down's screening in mid-pregnancy, is an important method to screen for fetal 2 1 trisomy syndrome, including screening for 18 trisomy syndrome (one chromosome 18 is more than normal) and open neural tube defect (NTD).

Both of them mainly include one of the most common chromosomal diseases-21trisomy syndrome, also known as Down syndrome. All fetuses with Down syndrome should be screened before delivery to avoid the birth of children.

From the perspective of national health eugenics, although there is a certain probability of misdiagnosis, Tang poetry screening has the advantage of low cost and can be popularized. After removing the low-risk population, it is usually necessary to further improve the inspection of the high-risk population.

For small families with good economic conditions, it is also good to skip the screening step and directly choose non-invasive DNA testing. Although the price is much higher, the accuracy rate can reach 99%.

Either way, it is highly recommended and should be done.

Non-invasive DNA is a new gene detection method. Its main collection object is fetal DNA that is free from pregnant women's blood. By examining the biological sequence, we can determine whether 2 1- trisomy, 18- trisomy and 13- trisomy are abnormal. Through non-invasive DNA, whether the fetus has genetic abnormality can be detected, so as to judge the probability of abnormal baby.

Take chromosome 13- trisomy as an example, and simply explain it to pregnant mothers:

Humans have 23 pairs of chromosomes, and each chromosome has two. Under normal circumstances, human cells should have two chromosomes 13. If there is 1 chromosome 13, we call it 13- trisomy.

It belongs to chromosome malformation, which will lead to fetal malformation and mental retardation, and can decide whether a pregnant woman will continue her pregnancy.

China now has two kinds of non-invasive DNA. If the price is less than 2000 yuan, only chromosome 13. 18.2 1 can be detected as trisomy, and other genes cannot be identified. In view of these restrictions, the price is slightly lower.

There is also a test that costs about 3000 yuan. Many people call this test an "upgraded version" of the basic test. It can not only detect the deletion of the whole gene, but also detect the abnormality of sex chromosome. The testing function is more perfect, and the price naturally rises.

Some female friends have heard that non-invasive DNA is good after pregnancy, so they must do it. Actually, this is a misunderstanding. Not all pregnant women need to do noninvasive DNA. So under what circumstances do pregnant women need to do non-invasive DNA? Let's talk about noninvasive DNA today.

What is noninvasive DNA? Noninvasive DNA is a detection method to detect fetal chromosomal abnormalities. Also known as non-invasive fetal chromosome aneuploidy detection. Non-invasive DNA only needs to take the venous blood of pregnant women and sequence the free DNA fragments (including fetal free DNA) in maternal peripheral plasma, so as to detect whether the fetus has three chromosome diseases: 2 1 trisomy syndrome (Down syndrome),1trisomy syndrome (Edwards syndrome) and1trisomy syndrome (Patao syndrome).

In other words, non-invasive DNA can only detect non-integer multiples of three pairs of chromosomes.

Applicable population of non-invasive DNA

1.35 years old pregnant women;

4. Some pregnant women have physical problems, such as carrying viruses, or placental abnormalities, such as placenta previa or placenta previa.

5. Pregnant women with positive serum screening.

6. We hope to exclude fetal 2 1 trisomy, 18 trisomy and 13 trisomy syndrome, and voluntarily choose pregnant women for non-invasive prenatal testing.

Several points to be explained about non-invasive DNA From this we can see that any pregnant woman who is willing to do non-invasive DNA can accept this test as long as conditions permit. But this is not mandatory.

First of all, I am not a doctor. I just said why I chose to do non-invasive DNA when I was pregnant with my daughter. What I said may not be accurate. You are welcome to criticize and correct me.

Because progesterone was always low in the early pregnancy, I took anti-abortion drugs for more than a month, and went to the hospital for record 12 weeks. The doctor asked me whether I should choose to do non-invasive DNA at my own expense at 2 100 or do Tang sieve at my own expense at 800.

Which one should I choose? I also did some homework in advance. Under the doctor's explanation, I know that both non-invasive DNA and Tang Screen are tested by taking venous blood. The main test items of Tang sieve are neural tube defect symptoms, 18- trisomy and 13- trisomy syndrome; The main items of noninvasive DNA examination are 2 1- trisomy syndrome (Down syndrome), 18- trisomy syndrome (Edwards syndrome) and 13- trisomy syndrome (Patau syndrome).

Compared with non-invasive DNA, the detection accuracy of Tang Sieve is about 70%, while the detection accuracy of non-invasive DNA for 2 1- trisomy syndrome (Down syndrome), 18- trisomy syndrome (Edwards syndrome) and 13- trisomy syndrome (Patau syndrome) is 99%.

But the doctor also told me that although the accuracy of non-invasive DNA is relatively high, there may still be misjudgment or false positive. If the non-invasive DNA test results are high-risk or borderline high-risk, in view of your age (I was already 4 1! Shh! ) and have experienced spontaneous abortion before, it is best to do amniocentesis again.

The so-called amniocentesis is that under the guidance of ultrasound, a slender needle passes through the pregnant woman's stomach, through the uterine wall, into the amniocentesis, and the amniotic fluid is extracted for a comprehensive examination. The accuracy can almost reach 100%.

Combined with my own situation, I chose non-invasive at that time. But I heard doctors tell other pregnant women that if the pregnant mother is young, still in the first trimester, or if one of the husband and wife has a definite chromosomal abnormality, of course, the specific doctor will decide according to the specific situation.

In other words, non-invasive DNA is not something that every pregnant woman needs to do.

No, this can be decided according to the results of your usual physical examination and the doctor's advice. If you are not an elderly woman, the usual examinations are done on time. If there is no problem, you don't have to do it.

I haven't done it, so I usually go to the birth check-up on time. No problem, and the doctor didn't ask me to do too many tests.

First of all, non-invasive DNA is very expensive. When I 13 did it in Fuzhou, it cost 2800 yuan. Not everyone is willing to pay such a price.

I chose to be non-invasive because I was too scared. If your pregnancy test is normal, you don't need to do noninvasive dna.

The premise of non-invasive is that Down's screening is high risk, and then the hospital wants you to do further amniocentesis. I think amniocentesis is terrible, so I dare not do it before choosing noninvasive. Noninvasive and simple. It's just a blood draw

2021/21revised answer: sheep puncture and non-invasive DNA are two different things.

This is a good suggestion. I happen to have personal experience.

The screening results of my baby during pregnancy show high risk. At that time, the doctor suggested sheep wear.

We are all at a loss, and we can imagine the mood at that time.

Consult all kinds of information and consult the doctor repeatedly, for fear that sheep wear will cause harm to the baby.

If you don't do it, you will be afraid. After all, the results of Tang sieve suggest high risk.

Finally, I made up my mind to make sheep wear, and the result of sheep wear was pleasant, which ruled out the risk of Down's.

Finally gave birth to a smart and lively baby!