What is the normal value of NTD risk?

In clinical medicine, many pregnant women will undergo some tests, among which Down syndrome screening is the test item that many pregnant friends will choose. However, for some pregnant women during the examination, there are usually some problems in the data, which increases everyone’s anxiety. So what should we do if the Down syndrome screening NTD is positive?

How much is the NTD risk standard worth?

NTD is a neural tube defect screening and is a key part of Down syndrome screening. The standard value is mostly between 0.6 and 2.5 mom. If it exceeds this value, the pregnant woman may be identified as a high-risk pregnant woman for neural tube defects.

What should I do if the Down syndrome screening test is positive for NTD?

If the Down syndrome screening test result is positive and the risk is very high, further testing is recommended. Amniocentesis can be performed to determine whether the baby's development is normal.

The purpose of Down syndrome screening is to screen out possible Down syndrome babies (also known as trisomy 21 or congenital idiocy) during pregnancy. This type of disease is the result of chromosomal abnormalities, caused by an abnormality in the total number of sex chromosome 21. Every test tube pregnancy has the possibility of chromosomal abnormalities, including trisomy 21, and the incidence of this disease is relatively high, with a newborn incidence rate of about 1/700. Its occurrence is random and accidental. There may be no family history or established history of exposure to harmful substances. The incidence rate increases with the age of the pregnant woman.

Down syndrome screening is only a method of identification and evaluation, not a diagnostic test. If the Down syndrome screening result is high risk for NTD, further diagnosis must be made through other methods. You can choose to have amniocentesis to check whether the baby's development is normal.

Expectant mothers whose Down syndrome screening results are "high risk" need to be diagnosed whether their fetus has Down syndrome. The most common technology for prenatal examination at present is amniocentesis, that is, under the guidance of B-ultrasound, a needle is inserted into the amniotic fluid of the pregnant woman through the abdomen to extract the amniotic fluid and perform sex chromosome analysis on the fetal cells.

Is it necessary to do Down syndrome screening?

Down screening refers to the prenatal selection test for Down syndrome. Its purpose is to test the blood of pregnant women, test the concentrations of alpha-fetoprotein, human gonadotropin and free estriol in the blood cells of pregnant women, and combine the clinical information of the pregnant women such as age, weight, smoking and whether they have any diseases to comprehensively calculate the risk of congenital defects in the fetus. The general accuracy is about 80%.

First of all, it is recommended that every pregnant woman should be checked. Down syndrome is also known as trisomy 21 or congenital idiocy. Patients have severely low IQ, cannot be independent in daily life and are accompanied by complex cardiovascular diseases. They require long-term care from family members, which will cause great pressure on the family. Because Down syndrome is a sporadic disease, every pregnant woman has the potential to give birth to a "Down syndrome baby". Down syndrome blood cell screening is a very effective way to check for Down syndrome babies, and it is recommended that every pregnant woman must undergo Down syndrome screening.

Secondly, older pregnant women should not be ignored. Since the probability of a fetus developing developmental abnormalities such as Down syndrome is related to the mother's age, older pregnant women are particularly required to undergo Down syndrome screening. Studies have shown that if a pregnant woman is over 30 years old, the probability of her baby having Down syndrome is 1/1000. If the pregnant woman is over 35 years old, the probability increases to 1/300. If the pregnant woman is between 35 and 39 years old, the probability is 1/50. If the pregnant woman is over 40 years old, the probability is 1/20.