What is Down's Screening?

Down's syndrome screening is mainly to find out what Down's syndrome is, which is an accidental disease, so every pregnant woman may give birth to a "Down's child". The probability of giving birth to Down's baby will increase with the age of pregnant women. Children with Down syndrome have severe mental retardation, congenital stupidity, tongue extension dementia, inability to take care of themselves, complicated with cardiovascular diseases, etc. They need long-term care from their families, which will cause great mental and economic burden to their families. Therefore, pregnant women should be screened for Down syndrome before delivery. To do Down's screening, we must first understand what Down's screening is. Tang screening test is to accurately calculate the risk of Down's syndrome fetus of each pregnant woman by detecting the concentrations of alpha-fetoprotein (AFP), human chorionic gonadotropin (β-hCG), free estriol (uE3) and inhibin A(InhibinA) in the blood of pregnant women, and combining with the age of pregnant women. The specific method of down syndrome screening is to take chorionic blood or amniotic fluid for cell culture, and then do chromosome karyotype analysis. If there is a map of 2 1- trisomy syndrome, the fetus can be diagnosed as Down syndrome. The Chinese name of AFP is alpha fetoprotein. For example, the increase of AFP in maternal blood and fetal amniotic fluid proves that the fetus has neural tube malformations, namely spina bifida, meningocele, anencephaly, microcephaly and hydrocephalus. The general range of alpha-fetoprotein (AFP) is 0.7-2.5MOM. The higher the chorionic gonadotropin, the lower the free estriol (uE3) and the higher the inhibin A(InhibinA), the higher the risk of Down syndrome in the fetus. In addition, the doctor will also input the maternal alpha-fetoprotein value, chorionic gonadotropin value, free estriol value, inhibin A value, age, weight and weeks of pregnancy into the computer, and the computer risk assessment software will calculate the risk of Down's syndrome in the fetus. Different hospitals use different standards. If the probability indicated by the test result (for example,1100) is greater than the normal reference value (for example,100)

Accuracy of Down's Screening According to the latest prenatal screening standards of the Ministry of Health, under the premise of a false positive rate of 5%, the detection rates of Down's screening by qualified testing units should be greater than 60%, 70% and 80% respectively. 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. That is to say, when the blood test index is high, there is a higher chance of giving birth to "Tang Bao", but it does not mean that there must be something wrong with the fetus. Just as pregnant women over the age of 35 are more likely to have "Tang Bao", it doesn't mean that there must be something wrong with their fetus. On the other hand, even if the detection index is normal, there is no guarantee that the fetus will not get sick. Pregnant women with Down's screening index higher than normal should have amniocentesis or chorionic villus examination, or non-invasive DNA examination. If the results of amniocentesis or chorionic villus examination are normal, the possibility of Down syndrome can be ruled out to the greatest extent. Problems needing attention during 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. Generally speaking, 15-20 weeks of pregnancy is the best time for Down's screening. Expectant mothers should not forget to make an appointment with a pregnancy test doctor. Although many expectant mothers question Down's screening, although the results of Down's screening can not accurately judge whether the baby is stupid, it is the most economical, simple and non-invasive detection method to judge whether the baby is stupid. If the result is suspicious, further amniocentesis can be done. Because children with Down's syndrome are severely mentally retarded, they can't take care of themselves at all, and they carry multiple system complications, which can't be cured for life. Therefore, in order to avoid Down syndrome, it is very important to do Down syndrome screening during pregnancy.