Down syndrome screening test 21 high risk

What does high risk of trisomy 21 in Down syndrome screening mean? What pregnant women who are doing Down syndrome screening are most worried about is the high risk situation. But in fact, high risk of Down syndrome does not mean that the fetus will definitely have deformities. Further amniocentesis is needed. Only based on the amniocentesis can a diagnosis be made.

What does the high risk of 21 trisomy in Down syndrome screening mean?

Trisomy 21 syndrome is a congenital fetal chromosomal abnormality, which mainly affects the child's IQ. After birth, it will increase the pressure on family and society. Therefore, if it can be diagnosed, it is best not to do it. Screening is high risk nowadays, so it is better to do an amniocentesis for diagnosis to avoid a heavy burden later. The adverse effect of Down syndrome with a higher risk is congenital intellectual disability in the fetus, which is directly related to genetic inheritance and maintenance during pregnancy. As long as there is no problem in the family and the baby develops normally, there is no problem. The risk level varies according to the age and physical fitness of the pregnant woman. The probability of occurrence is extremely low, so there is no need to worry.

Screening is only an assessment, not a diagnosis, but for high-risk situations, amniocentesis is necessary for diagnosis. If it is a congenital sex chromosome abnormality, there is no way to intervene and treat it at this stage, the only option is to terminate the pregnancy.

Necessity of Down syndrome screening

Down syndrome screening is a survey work currently carried out on all pregnant women in my country to prevent the birth of children with congenital mental retardation. The meaning of "Down's" is what we often call "Down syndrome". "Congenital idiocy" is also called "Trisomy 21 syndrome", which is a chromosomal disease. Normal people have only a pair of chromosome 21 (two), while the chromosome 21 of trisomy 21 children becomes three, which causes the fetus to have severe multiple developmental malformations (unusual appearance, congenital heart disease, abnormal function of major internal organs and physical abnormalities), accompanied by severe intellectual disabilities. The baby is basically unable to be independent in daily life, and most patients die before the age of 18. Therefore, prenatal diagnosis and confirmation are very important.

In fact, screening for Down syndrome is a minimally invasive test that requires little economic effort, namely B-ultrasound and mid-pregnancy serological screening. Expectant mothers do not need to worry too much about the economic pressure caused by the test. Based on applied statistical calculations, screening results are divided into high risk or low risk. When the risk value exceeds 1/380 (the risk value of some testing methods exceeds 1/280), it is high risk, because those over 35 years old are older pregnant women, and the average risk of 35-year-old pregnant women giving birth to congenitally mentally retarded babies is about 1/380, so the risk cut-off value is set to 1/380.

If it is higher than this value, it is high risk, otherwise it is low risk. Only when the screening prompts a high risk is further prenatal examination recommended, namely "amniocentesis" to analyze the fetus's sex chromosomes and ultimately make a diagnosis of whether there is an abnormality. Amniocentesis is also a safe diagnosis method and there is no need to worry. But generally speaking, the decision-making power lies with the pregnant woman herself.