Down syndrome, also known as \”congenital stupidity\” or \”trisomy 21\”, specifically refers to the change of chromosome 21 from the normal chromosome 2 to chromosome 3. It is one of the most common congenital defects in my country.
Ms. Lin was screened for Down syndrome when she was 18 weeks pregnant, and the result was 1/100. The doctor said calmly that the child may not have Down syndrome. As soon as she was discharged from the hospital, she couldn\’t control her tears and was frightened. These past few days, she was tossing and turning as if celebrating the New Year. Is she still a child? What is Down\’s syndrome
About Down syndrome
Down syndrome, also known as \”congenital stupidity\” or \”trisomy 21\”, specifically refers to the change of chromosome 21 from normal chromosome 2 to chromosome 3. It is a disease caused by congenital chromosomal abnormalities and multi-gene aberrations. One of the birth defects with the highest incidence in our country. Most children with Down syndrome are severely mentally retarded, accompanied by congenital heart disease, leukemia, digestive tract malformations and other problems. They cannot take care of themselves and have a short life span. The average survival age is only 20-30 years old. Generally between 20-50.
Which couples are more likely to give birth to babies with Down syndrome?
It is reported that the incidence rate of Down syndrome in my country is 1/800-1/600, and the incidence rate of neural tube defects is 1/700. According to experts, due to environmental influences and abnormal living habits, modern people are prone to genetic mutations of their own. Any healthy couple is at risk of having a child with Down syndrome. The chance of having a baby with Down syndrome increases as the mother ages.
Experts remind that the following seven types of couples belong to high-risk groups:
1. Pregnant women have a history of viral infections before and after pregnancy, such as influenza, rubella, etc.
2. At the time of conception, one of the spouses has a chromosomal abnormality
3. One spouse is older
4. Pregnant women take teratogenic drugs such as tetracycline before and after pregnancy.
5. One of the spouses has been working under radioactive curtains or polluted environments for a long time
6. Pregnant women with a history of habitual miscarriage, premature birth or stillbirth
7. One spouse keeps pets for a long time.
There are currently neither effective preventive measures nor effective treatments for Down syndrome. Only through prenatal screening can early detection and timely measures be taken. Currently, Down syndrome can be discovered through Down syndrome screening, and 80% of Down syndrome cases can be discovered through prenatal screening and prenatal diagnosis.
About Down syndrome screening
1. The purpose of Down syndrome screening
The risk of a fetus having Down syndrome can be determined by testing a pregnant woman\’s blood. If the results of Down syndrome screening indicate that the fetus is at higher risk of having Down syndrome, further diagnosis should be performedSexual examination – amniocentesis. Or velvet inspection.
2. Down syndrome screening method
Combined serology methods are commonly used to screen for Down syndrome. Collect the peripheral blood of pregnant women, extract serum (without fasting), detect maternal serum alpha-fetoprotein (AFP) and serum chorionic gonadotropin (HCG) concentrations, and calculate \”risk factors\” by combining the expected date of delivery, the maternal age and gestational age, and weight. , so that 80% of congenital fools can be detected. At the same time, this examination can also detect high-risk pregnant women with neural tube defects, trisomy 18, and trisomy 13.
3. Choose the appropriate period of pregnancy for Down syndrome screening
It is generally recommended that expectant mothers must go to the hospital for examinations in this area between 14 and 20 weeks of pregnancy. If, during the screening process, the hospital\’s report identifies a high-risk condition.
4. When test results are known
When pregnant women return to the outpatient clinic for routine prenatal check-ups 2-3 weeks after the blood draw, the outpatient doctor will inform them of the results. If the serum screen is positive, an amniotic fluid test is required to confirm the diagnosis.
5. Down syndrome screening test results
The normal value of alpha-fetoprotein (AFP) should be greater than 2.5MoM. The lower the detection value, the higher the chance of the fetus having Down syndrome. The higher the level of chorionic gonadotropin (HCG), the higher the chance that the fetus will have Down syndrome. In addition, the doctor will input the alpha-fetoprotein value, chorionic gonadotropin value, and the maternal age, weight, and gestational age into the computer, and the computer will calculate the risk of the fetus suffering from Down syndrome. If the test result shows that the risk is less than 1/270, it means that the risk is relatively low, and the chance of the fetus having Down syndrome is less than 1%. However, if the risk is higher than 1/270, it means that the risk of fetal disease is high, and further amniocentesis or chorionic villus examination should be performed.
6. People who need Down syndrome screening
Every pregnant woman should be screened for Down syndrome. The occurrence of Down syndrome is random. Only about 1% of Down syndrome patients are related to genetic factors, and other causative factors are unknown. According to literature statistics, among all children born with Down syndrome, 30% are born to women over 35 years old, and 70% are born to pregnant women under 35 years old.
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About the accuracy of Down syndrome screening
Down syndrome screening can detect 60-70% of children with Down syndrome. It needs to be clear that Down syndrome screening can only help determine the probability of a fetus having Down syndrome, but it cannot determine whether the fetus has Down syndrome. In other words, when the blood test indicators are high, the probability of conceiving a \”Tang\” baby is high, but it does not mean that there will be problems with the fetus. Just like pregnant women over 35 years old have a higher chance of having a \”Tang\” baby, but it does not mean that there will be problems with the fetus. On the other hand, even if the laboratory test indicators are normal, there is no guarantee that the fetus will not get sick.
Pregnant women whose Down syndrome screening index exceeds the normal value should undergo amniocentesis or chorionic villus examination. If the amniocentesis or chorionic villus test results are normal, Down syndrome is 100% ruled out.
The hospital\’s Down syndrome screening results can only indicate the probability that the baby has Down syndrome, not a high-risk baby. For example, the risk coefficient for trisomy 21 is 1/100, which means that a mutation on chromosome 21 will produce a fetus that is congenitally stupid. The probability is 1/100, maybe you are one of the 1/100 people who have a problem, maybe you are one of the 99/100 people who have no problem; low risk does not mean that the baby will definitely be fine, even if the risk coefficient is one in ten thousand, there is still a ten thousandth One possibility. Therefore, the fetuses of high-risk pregnant women may not be stupid; the fetuses of non-high-risk pregnant women may not be stupid.
Although the results of Tang screening cannot accurately determine whether the baby is stupid, after all, it is the most economical, simple and harmless method to determine whether the baby is stupid. If the results are suspicious, further amniocentesis may be performed. A child with Down syndrome is born in China approximately every 20 minutes. Children with Down syndrome are born with severe mental retardation.
She is completely unable to take care of herself and carries multiple systemic complications that cannot be cured throughout her life, thus placing a heavy mental and financial burden on her family. Therefore, it is necessary to go to the hospital for a Down syndrome screening.