Down’s syndrome screening is a simple, economical and non-invasive way to identify pregnant women at high risk of having a fetus with congenital dysfunction. Congenital dysgenesis is one of the leading causes of severe congenital mental retardation, and every woman who becomes pregnant is at risk of having a child with Down’s syndrome. The chance of having a child with Down’s syndrome increases with the age of the mother. Testing is recommended between the 15th and 20th week of pregnancy. The risk factor for a Down’s syndrome child is calculated by taking the mother’s serum and measuring the concentration of alpha-fetoprotein and chorionic glandular hormone in the mother’s serum, taking into account the pregnancy, age and the week of pregnancy when the blood is taken. This test detects about 80% of fetuses with Down’s syndrome, trisomy 18, and neural tube abnormalities. When a woman is 35 years old or older, there is a higher probability of Down’s syndrome and direct amniocentesis is recommended. Second, blood glucose monitoring to avoid the risk of hyperglycemia Screening time: 24-28 weeks of pregnancy Due to the hormonal changes in pregnancy, the chances of maternal diabetes may occur or be detected increase. Hyperglycemia in pregnancy can lead to an oversized fetus. A full-term giant baby must be delivered by cesarean section. Diabetes may also lead to stillbirths or malformations. If detected early, diabetes can be easily controlled with a controlled diet or insulin injections. Results: Three tests (fasting, 1 hour and 2 hours) with values of 5.1, 10.0 and 8.5 mmol/L are considered normal. Third, ultrasound, visual monitoring of fetal development under normal circumstances, ultrasound examination is an essential auxiliary examination in maternity checkup, which can see the fetal body, head, fetal heartbeat, placenta, wool and umbilical cord, etc. It can find out whether the fetus is alive, whether there are multiple births, and even identify whether the fetus is malformed. A total of 5-6 ultrasound examinations are essential throughout pregnancy: 1. 12 weeks of pregnancy: to check whether the fetus matches the gestational week, as well as to determine the due date and NT value 2. 20-24 weeks of pregnancy: fetal malformation screening; (can also be done in two sessions) 3. 30 weeks of pregnancy: to understand the development of the fetus, whether there are physical malformations, but also to further understand the position of the fetus and the amount of amniotic fluid. 4. 37 weeks of pregnancy: prenatal To determine the fetal position, fetal size, placental maturity, and the presence of umbilical cord circumference for the final assessment before delivery.5.40 weeks of pregnancy: to determine the fetal size, amniotic fluid, and placental maturity.