Down screening refers to the screening for Down’s syndrome, which is performed by drawing blood from pregnant women and performing biochemical tests on the serum drawn, as described below:
1. Screening for Down’s syndrome needs to be carried out when the patient is 16-20 weeks pregnant, and the pregnant woman is instructed to draw blood on an empty stomach before the relevant screening is done.
2. Blood is drawn from the pregnant woman for the purpose of detecting the concentrations of alpha-fetoprotein, human chorionic gonadotropin and free estriol in the maternal peripheral blood.
3. NT is then measured by ultrasound, and finally a judgment is made based on a combination of the pregnant woman’s height, weight, gestational week, blood pressure, and the results of the blood draw.
To screen for Down syndrome, you need to go to the hospital to see a professional doctor for the test, and the test precautions should be carried out according to the doctor’s instructions.