Down syndrome screening normal values ​​for trisomy 18

Every pregnant woman may have a baby with Down syndrome, so prenatal diagnosis of Down syndrome should be carried out. Down syndrome screening is carried out at 15-20 weeks of pregnancy. It is based on a combination of serological and B-ultrasound tests, and a comprehensive risk assessment is conducted based on the pregnant woman's age, weight, weeks of pregnancy, medical history, etc. So how much is the Down syndrome screening trisomy 18 standard worth?

The standard value of Down syndrome screening for trisomy 18 is lower than 1/350. It is best to go to a reliable hospital for testing, as the test results are more accurate. It is generally recommended to go to the hospital for examination within 16-20 weeks of pregnancy. Blood tests can be performed. If the Down syndrome screening shows abnormalities, further examination is required. You can go to the hospital for amniocentesis. You can also have a blood test for genetic tests. If the test is normal, don't worry. It is best to go to the hospital for a four-dimensional color ultrasound examination and a B-ultrasound to exclude fetal anomalies at 24-26 weeks of pregnancy. During pregnancy, pay attention to rest, improve nutrition and diet, it is best not to eat foods that are prone to miscarriage, such as dried longan, hawthorn, hairy crab, etc. It is recommended to eat more fresh vegetables and fruits to supplement vitamins.

The following contents are related to Down syndrome screening:

1. Screening time: The best time is between 15 and 20 weeks of pregnancy.

2. The economic development is simple and will not harm the fetus. Although the Down syndrome screening results cannot accurately determine whether the fetus is mentally retarded, it is the most economical, simple and harmless test method for the fetus to determine whether the fetus is mentally retarded. If the result is high-risk, amniocentesis can be further performed.

3. Screening method: Synergistic serology is often used to screen for Down syndrome. Extract the peripheral blood of pregnant women, obtain blood cells (no need to fast), test the concentration of alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in the mother's blood cells, and calculate the risk factor based on the pregnant woman's date of birth, age, gestational age and weight at the time of blood test. In this way, 80% of congenital idiocy can be detected.

4. Cost: around 100 yuan, but the outpatient standards of each hospital across the country are different.

5. Preparation before the test: You do not need to be on an empty stomach for Down syndrome screening, but it is related to the menstrual cycle, weight, height, exact gestational age, and gestational age. Before the screening, pregnant women need to provide more detailed personal information, including date of birth, due date, weight, whether they have insulin-dependent diabetes, twins, whether they smoke, and history of abnormal pregnancy. Because the risk rate analysis of screening needs to be adjusted according to the above factors, it is also very important to fill out the test form before the blood test. 6. Down syndrome screening is temporarily inappropriate for those who are undergoing in vitro fertilization or twin pregnancy.