How many weeks does Down syndrome screening have a high accuracy rate?

When a woman becomes pregnant, she must take prenatal checkups seriously and go to the hospital for checkups on time as required. Checkups during pregnancy are carried out to ensure the normal development of the pregnant woman and fetus. Down syndrome screening is one of the more important examinations. When conducting this examination, you can promptly understand the probability that the fetus may suffer from Down syndrome.

How many weeks should Down syndrome screening be done to increase accuracy?

Down syndrome screening can be performed between 15 and 20 weeks of pregnancy, with the best time being between 16 and 18 weeks. Down syndrome screening mainly determines the risk of the fetus suffering from Down syndrome by testing the pregnant woman's blood. If the results of the Down syndrome screening show that the fetus is at a higher risk of suffering from Down syndrome, further confirmatory tests should be carried out - amniocentesis or chorionic villus sampling.

Down syndrome screening is a test to screen the possibility of a fetus having Down syndrome. Blood is usually drawn between 16 and 20 weeks of pregnancy. The test requires fasting. The result is not a final diagnosis, but a risk factor with an accuracy rate between 70-80%. Doctors generally recommend voluntary examinations, which are not mandatory, but are best for older pregnant women. Personally, I don’t think it’s necessary to do this. If you take high-risk actions, it will increase the psychological burden on pregnant women. You just need to go to the hospital for a four-dimensional color ultrasound to screen for fetal abnormalities during the 22nd to 26th week of pregnancy.

The best time for Down syndrome screening is between 15 and 20 weeks of pregnancy. Preparation before the examination: There is no need to fast for Down syndrome screening, but it is related to the menstrual cycle, weight, height, accurate gestational age, and fetal age. It is best to consult a doctor for other preparations before the examination.

Down syndrome screening can be done between 14 and 18 weeks, and it is better to do four-dimensional color ultrasound at 22-28 weeks. Down syndrome screening only checks whether the baby is at risk of Down syndrome. The four-dimensional color Doppler ultrasound will check the baby's facial features, spina bifida, brain, kidney, heart, bone dysplasia, etc.

Reasons for high risk of Down syndrome screening

1. Age Factor

As the age of pregnant women increases, the incidence of fetal chromosomal abnormalities increases significantly, which is caused by aging of egg cells, uneven division and abnormal egg conception. Pregnant women who are 35 years old or older at the time of delivery should undergo prenatal diagnosis of fetal chromosomes.

2. Genetic factors

If a child with Down syndrome was born in one of the family members or one of the spouses had a chromosomal abnormality during conception, the disease may be inherited.

3. Drug factors

Before and after pregnancy, if pregnant women take teratogenic drugs, such as tetracycline, or take too many pregnancy-preserving drugs, there is a risk of having a baby with Down syndrome or affecting the results of the sugar screening.

4. Health factors

Pregnant women have a history of viral infection, such as influenza, rubella, etc., or a history of habitual miscarriage, premature birth or stillbirth, etc.

5. Environmental factors

One of the spouses works under a radioactive screen or in a polluted environment for a long time, or keeps pets for a long time.