What if the risk of Down's screening is high? What if Tang's screening risk is high?

After pregnancy, expectant mothers usually have to do a lot of tests, one of which is Down's screening. Some people find that the risk is high after doing Down's screening. What if the risk of Down's screening is high? What if Tang's screening risk is high?

1. What if the risk of Down's screening is high?

(1) Do amniocentesis.

Amniocentesis has a certain risk of infection, so doctors generally don't recommend it, but if the risk of Down's screening is high, doctors will still ask for further examination, and most of them will choose amniocentesis. After all, it belongs to DNA testing with high accuracy.

(2) Do non-invasive NDA examination.

At present, there is also DNA testing, which takes the blood of pregnant women for non-invasive testing, so the testing has little effect on the fetus. If the fetus is unstable for many times, it is recommended to choose.

(3) Stop pregnancy

The test results of Down's screening can only show the risk, but can't make a definite diagnosis. Therefore, other tests are needed. If it is detected that the fetus is baby Tang, it is recommended to terminate the pregnancy. After all, the baby with trisomy syndrome belongs to congenital stupidity, which has a great influence on later life and cannot be cured.

(4) Is the result of high risk Tang Baobao?

It is not necessarily Tang Bao who is at high risk of Down's screening. Down's screening is a probabilistic examination, which means it is a high risk. It can only be said that the risk of baby Tang is greater than others, especially pregnant women over 35 years old, but this does not mean that it must be baby Tang, and high-risk groups need further examination and diagnosis.

(5) Is Down's screening accurate?

Down syndrome screening can screen 60-70% of children with Down syndrome. It needs to be clear that the screening test can only help to judge the probability of Down's syndrome in the fetus, but can't determine whether the fetus has Down's syndrome. In other words, when the blood test index is high, the chances of having a "Tang" baby are higher, but it does not mean that there must be something wrong with the fetus. Just as an elderly pregnant woman over the age of 35 is more likely to give birth to a "Tang" baby, it does not mean that there must be something wrong with the fetus.

2. When will Down's screening be done?

(1) What is down screening?

Tang screening is short for prenatal screening. The purpose is to judge the risk of Down syndrome in the fetus by detecting the blood of pregnant women. If the results of screening in early Tang Dynasty show that the risk of Down's syndrome is high, further diagnostic examination-amniocentesis or chorionic villus examination should be carried out.

(2) When will Down's screening be done?

Down's screening can be carried out within 0/0 ~ 20 weeks of pregnancy, which is mainly divided into two periods.

First pregnancy

The examination of the first pregnancy is mainly in the pregnant mother 10- 13 weeks, using ultrasound and blood drawing. Ultrasound can clearly measure the thickness of the zona pellucida in the fetal neck, and blood test can measure the values of plasma protein A and chorionic gonadotropin in maternal serum to estimate the risk of Down syndrome in the fetus.

Second pregnancy

During the second pregnancy, the pregnant mother mainly received blood tests at the 15-20 week, the main purpose of which was to detect the levels of serum alpha-fetoprotein, chorionic gonadotropin, free estriol and inhibin, and to calculate the risk of Down syndrome of the fetus according to the age, gestational age and weight of the pregnant mother.

(3) Why do you want to do Down's screening?

Because Down syndrome is an accidental disease, the probability of its occurrence is one in eight hundred to one in one thousand, and there is no obvious genetic tendency. However, this probability will increase with the age of pregnant women. Children with Down syndrome have severe mental retardation, congenital stupidity, tongue coating dementia and can't take care of themselves.

Accompanied by complex cardiovascular diseases, family members need long-term care, which will cause great mental and economic burden to the family. Therefore, pregnant women should be screened for Down syndrome before delivery.

(4) How to do Down's screening?

Down's screening mainly includes extracting pregnant women's serum and detecting pregnancy-associated plasma protein A(PAPP-A) and free hCGB subunit (early stage).

Or alpha fetoprotein (AFP), chorionic gonadotropin (HCG) and free estriol (uE3) (mid-term), combined with the expected date of delivery, weight, age and gestational age at the time of blood collection, the risk coefficient of Down's infant can be calculated, so that 80% of Down's infants can be detected.

In the detection of many indexes of maternal serum prenatal screening, radioimmunoassay, enzyme immunoassay, time-resolved immunofluorescence and chemiluminescence are generally used. because

The results of radioimmunoassay and enzyme immunoassay are quite different. At present, time-resolved immunofluorescence and chemiluminescence are generally used, and time-resolved immunofluorescence is recommended by the state.

(5) How to treat the results of Down's screening?

alpha-fetoprotein

Alpha-fetoprotein is a kind of fetal specific globulin, and its normal value should be greater than 2.5MoM. The serum AFP level of pregnant women with congenital stupid fetus is 70% of that of normal pregnant women. The lower the test value, the higher the risk of Down syndrome in the fetus.

MoM is a multiple of the median, which refers to how many times the detection result of serum markers of pregnant women in prenatal screening is the median concentration of serum markers of normal pregnant women in this gestational age.

Free β subunit chorionic gonadotropin

The serum chorionic gonadotropin level of pregnant women with congenital idiot fetus is nourishing, and the higher the index, the higher the probability of Down syndrome.

estriol

Free estriol is the main estrogen produced by fetal placenta, and the value of uE3 in the blood of pregnant women with congenital idiocy is decreased.

Screening value of blood test

If the blood test screening value is greater than the international standard 1/270, pregnant women belong to the high-risk group. It is more likely that the high-risk group only says that the fetus is a Down's baby, and the low-risk group may also give birth to a Down's baby.

It should be noted that because the calculation methods of various hospitals are not exactly the same, the standards are also different. The normal value is about 1/700, and the international standard is 1/270. If it is less than these two values, the risk is relatively low.

(6) Matters needing attention in screening

During prenatal screening, pregnant women need to provide more detailed personal data, including the second menstruation at the end of the year of birth, weight, whether insulin-dependent diabetes, whether twins have a history of abnormal pregnancy due to smoking, etc. Because the statistics of screening risk rate need to be revised according to the above factors, it is also very important to fill in the test sheet before blood drawing.

(7) Does Down's screening require fasting?

Unlike the general physical examination involving liver function, Down's screening does not require fasting. Recently, I found that some female friends are not sure whether they need an empty stomach, mainly because Down's screening is called Tang screen for short, which is very different from another word, sugar screen.

Yes, it sounds exactly the same. But unlike Down's screening, glucose screening is used to screen gestational diabetes mellitus, which is usually done at 24 weeks and needs fasting 12 hours. So, if you have any questions or are unclear, you might as well ask the doctor what the test list is like.

3. What does Down's screening check?

(1) What is down screening?

Down's screening is a method to determine the risk factors of fetal congenital stupidity and neural tube defects by extracting the serum of pregnant women, detecting the concentrations of fetal protein A, chorionic gonadotropin and free estriol in maternal serum, and combining the expected date of delivery, weight, age and gestational age of pregnant women.

(2) Why should Down's screening be conducted?

Any pregnant woman may be pregnant with a fetus with Down syndrome. Children with Down syndrome have severe mental retardation, congenital stupidity, tongue extension dementia, and can't take care of themselves completely, accompanied by complex cardiovascular diseases, which can't be cured for life, and will bring heavy mental and economic burden to the family. It is recommended that every pregnant woman be screened for Down syndrome. If the fetus is finally diagnosed as a patient with these congenital diseases, pregnant women can decide whether to continue their pregnancy.

(3) The examination contents of Down's screening

Screening for Down's Syndrome in First Pregnancy

This examination mainly applies two screening methods: ultrasound and blood drawing to pregnant mothers at 10 ~ 13+6 weeks. Through ultrasound, we can clearly measure the thickness of the zona pellucida of the fetus, plus blood test, and measure the values of plasma protein A and chorionic gonadotropin in maternal serum to estimate the risk of Down's syndrome in the fetus.

(4) Screening for Down syndrome in the second pregnancy.

Pregnant mothers receive blood samples at 15~20 weeks. The hospital will detect the levels of serum alpha-fetoprotein, chorionic gonadotropin, free estriol and inhibin, and then calculate the risk of Down syndrome of the fetus according to the age, gestational age and weight of the pregnant mother.

Chorionic sampling

When pregnant mothers want to do this test, they must discuss it with the doctor carefully first, because this is an invasive test, that is, they need to get some cell samples from the developing placenta. For example, he explained that if the first pregnancy is screened by the pregnant mother and the zona pellucida of the fetal neck is more than 3 mm, you can consider taking chorionic samples directly to detect chromosomes. However, this result will not be known until 14 days later.

amniocentesis

This is also an invasive examination, but its risk is less than chorionic sampling. The doctor said that if the amniotic fluid is extracted from the amniotic cavity of the pregnant mother's uterus for testing, you can know whether there is any abnormality in the chromosome of the fetus, and then you can know whether it is possible to suffer from Down's disease. It takes 14 days to know the result, and the accuracy rate is over 99%.

(5) Precautions

Down's syndrome screening is mainly to determine the risk of Down's syndrome by detecting the blood of pregnant women and combining with other clinical information. If Down's screening results show that the risk of Down's syndrome is high, further diagnostic examination-amniocentesis or chorionic villus examination should be carried out.

(6) Examination time of Down's screening

Screening time: the best time is pregnancy 15 ~ 20 weeks.

Preparation before examination: Down's screening does not need an empty stomach, but the peripheral blood of pregnant women can be taken, but Down's screening is related to menstrual cycle, weight, height, accurate gestational age and gestational age. It is best to consult a doctor about other preparations before the examination.