Prenatal screening for Down syndrome
Release time : 01/18/2025 18:13:27
Down Syndrome Prenatal Screening is a procedure that involves testing the fetus for Down syndrome (trisomy 21) during pregnancy. If the results of the screening indicate an increased risk, the decision to continue the pregnancy or to terminate it may be made based on the findings. In this article, we will explore the condition known as Down syndrome and delve into various aspects related to prenatal screening for this disorder.
What is prenatal screening for Down syndrome? Down syndrome, also known as trisomy 21, is a chromosomal abnormality.
Down syndrome can often be diagnosed prenatally, and the decision about whether to continue pregnancy depends on the situation. The purpose of Down Syndrome Prenatal Screening is to assess the risk of having a baby with Down syndrome by analyzing a pregnant woman's blood and other clinical information. If the results of the screening indicate a high risk of Down syndrome in the fetus, further diagnostic testing should be conducted, which includes amniocentesis or chorionic villus sampling (CVS). However, Down syndrome can lead to the fetus's death, and if it is born, the infant may experience developmental delays and multiple congenital anomalies.
What is Down syndrome? Down syndrome is a chromosome disorder, also known as 21-trisomy or congenital stupidity. It is caused by an abnormal number of chromosomes-an extra copy of the 21st chromosome-which results in various physical and intellectual disabilities in individuals with Down syndrome.
60% of the children were lost at an early stage in utero, and those who survived had obvious intellectual retardation, distinctive facial appearance, growth and developmental disorders, and multiple congenital malformations.
Although current technology can detect children with Down syndrome through prenatal examinations, treatment methods are still very limited, and generally the best way to detect children with Down syndrome is to terminate pregnancy. Because children with Down syndrome are born in time, their health status is not good, because children with Down syndrome are generally accompanied by a variety of diseases and their appearance is different from ordinary people. Moreover, male Down's babies grow up until puberty, they will not be fertile.
Children are often accompanied by other malformations such as congenital heart disease. Due to low immune function, they are prone to various infections. The incidence of leukemia is 10 to 30 times higher than that of normal.
If you survive into adulthood, symptoms of Alzheimer's disease often appear after the age of 30.
Therefore, many times, if this condition occurs during prenatal screening for Down syndrome, many new parents will choose to terminate the pregnancy, because this is by far the best response to Down syndrome being discovered during pregnancy.
Prenatal screening for Down syndrome is often not a one-step process that can be achieved. In fact, the detection of Down syndrome often requires multiple tests.
Screening for Down's syndrome generally requires making preparations, such as fasting water after 12 o'clock the night before screening, and it is best to perform the examination on an empty stomach. Examination for Down's syndrome is also related to menstrual cycle, weight, height, accurate gestational age, and gestational age, so you can generally make some inquiries from your doctor before conducting prenatal screening for Down's syndrome.
It is reported that Down syndrome prenatal screening includes blood sampling from pregnant women and ultrasound indicators such as NT (Nuchal translucency), or alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) and free urinary estrone (uE3) and inhibin A (Inhibin A). Based on the gestational age, weight, age of the pregnant woman, and the time of blood collection, the risk coefficient for a fetus with Down syndrome can be calculated. Thus, at a false positive rate of 5%, more than 80% of Down syndrome cases can be detected.
Generally speaking, prenatal screening for Down syndrome primarily involves two methods: prenatal screening and non-invasive DNA testing. However, to determine whether a fetus is affected with Down syndrome, amniocentesis is typically used.
Generally speaking, in the screening of multiple indicators by maternal serum prenatal test, it is generally used to be radioimmunoassay, enzyme immunoassay, time-resolved fluorescence immunoassay and chemiluminescence method.
Non-invasive prenatal testing (NIPT) is a method that uses fetal cells to be transferred through the placenta and into the mother's bloodstream. These cells are then destroyed by the mother's immune system, leaving behind the DNA of the fetus.
5 ml of maternal blood is sufficient to detect the fetal DNA.
Prenatal screening and non-invasive DNA testing generally provide a preliminary understanding of fetal conditions. To fully confirm the presence of Down syndrome in the fetus, amniocentesis is typically employed. Amniocentesis is appropriate for pregnant women between 16 to 20 weeks of gestation.
Amniocentesis is a procedure where the amniotic fluid is aspirated to examine cells that have been shed from the fetus, and to test their 21st chromosomes. This method has a high accuracy rate for testing Down syndrome (100%) and a very low risk of causing miscarriage.
The cost of Down syndrome prenatal screening is quite necessary for many pregnant women. In order not to have a baby with Down syndrome, many expectant mothers opt for this screening. However, the cost varies depending on the region and hospital. Generally speaking, the cost of Down syndrome prenatal screening is within 200 yuan. However, if the results of the initial screening indicate a high-risk fetus, further testing will be recommended by doctors. The cost of such additional testing also varies based on the hospital and the specific procedures involved.
Prenatal screening for Down syndrome: In order not to have a baby with Down syndrome, many pregnant women undergo prenatal screening for Down syndrome. However, what should be noted when conducting Down syndrome prenatal screening? In fact, there is generally no need for excessive anxiety before undergoing the screening. It is advisable to perform the screening on an empty stomach. However, being hungry is not necessary. The results of prenatal screening for Down syndrome are closely related to factors such as menstrual cycle, weight, height, accurate gestational age, and fetal size. Therefore, it is best to consult with a doctor before the screening and prepare adequately.
Generally speaking, the optimal time for prenatal screening for Down syndrome is between 15 and 20 weeks of pregnancy.
The prenatal screening for Down syndrome does not allow for determining the fetal sex; this claim is incorrect.
Down syndrome is a common chromosome disorder in humans, and it can be said that Down syndrome is also a very random disease, almost every mother could possibly give birth to a "Down baby".
However, individuals with Down syndrome often impose significant financial and family burdens on their families. Due to the intellectual disability and complete inability to care for themselves, parents often opt to terminate the pregnancy before birth if they are aware of the risk of having a child with Down syndrome. It is reported that almost all developed countries have implemented prenatal screening for Down syndrome in pregnant women, and China also recommends undergoing prenatal screening for Down syndrome during pregnancy for expectant mothers.
Many people claim that prenatal screening for Down syndrome can identify the fetus's sex. However, this claim is incorrect because prenatal screening only assesses the risk of Down syndrome and has no relation to the fetal sex.
FreeβHCG is a test for pregnant women's serum, not a test for the fetus.
Therefore, prenatal screening for Down syndrome does not provide information on the fetal sex.
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