Down syndrome, also known as Trisomy 21 syndrome or Down syndrome, is the most common chromosomal aneuploidy disorder in which a patient has one extra chromosome in the 21st pair compared to normal individuals. By detecting PAPPA in the serum of pregnant women The risk value calculated by risk assessment software is based on the content of AFP, HCG, uE3 and Inhibin A, combined with the age, gestational week, weight, smoking, insulin dependent diabetes and other clinical information of the pregnant woman.
The examination of Down syndrome is conducted through Down screening, which involves testing the blood of pregnant women and combining it with other clinical information to comprehensively determine the risk of Down syndrome in the fetus. If the Down screening results indicate a high risk of Down syndrome in the fetus, further diagnostic tests such as amniocentesis or chorionic villi examination should be performed.
Pregnant women of any age can conceive a fetus with chromosomal abnormalities, but the incidence of chromosomal abnormalities increases significantly with maternal age. For example, the probability of chromosomal abnormalities in pregnant women under the age of 25 is 1:1185, while it is as high as 1:335 at the age of 25. Therefore, pregnant women over the age of 25 need to undergo chromosome testing.
1. Down syndrome screening as a possibility test: high-risk individuals only say that the fetus is more likely to be Down syndrome, while low-risk individuals may also be Down syndrome
2. About 1/10 of all pregnant women are screened as high-risk groups, with 1~2/100 of high-risk groups being Down syndrome infants, meaning that 1~2/1000 of pregnant women are Down syndrome infants
3. When the blood test screening value is greater than 1/270, it is considered a high-risk population, and the normal value is around 1/700. The international standard is 1/270
4. The Down syndrome screening value is a corrected value. The factors that affect the screening value of Down syndrome mainly include: maternal age, gestational age, fetal alpha protein secretion, human chorionic gonadotropin secretion from the placenta, drug factors, genetic factors, etc. Eating "Duoli Mama" during prenatal care may cause the level of chorionic gonadotropin to exceed normal, which may affect the Down syndrome screening value.
The above are the relevant answers about Down syndrome. I hope it can help you. Finally, it should be reminded that due to the special nature of pregnant women's bodies, they still need to be taken care of in all aspects to avoid accidents.
