Laboratory tests, ultrasound, Down’s screening or non-invasive prenatal screening techniques, and glucose tolerance screening are done to ensure a smooth pregnancy. 1. Laboratory tests: Relevant laboratory tests, such as routine blood test, routine urine test, blood grouping, liver and kidney function, coagulation test, Hepatitis B test, HIV antibody screening, syphilis serum antibody screening and Hepatitis C antibody screening, should be performed during pregnancy to understand the basic conditions of pregnancy. 2. Ultrasonography: Ultrasonography should be performed in early pregnancy to identify intrauterine pregnancy, NT (nuchal translucency) measurement to screen the risk of chromosomal diseases in the fetus, systematic ultrasonography in mid-pregnancy, and ultrasonography in late pregnancy to find out the position of the fetus and the development of the fetus. 3. Down’s syndrome screening or non-invasive prenatal screening technology: in the middle of pregnancy for the low-risk group, Down’s syndrome screening is also carried out to screen the risk of chromosomal diseases in the fetus, and for the high-risk group, non-invasive prenatal screening technology or amniocentesis is carried out to screen the risk of the disease. 4. Glucose tolerance screening: Glucose tolerance screening should be carried out at 24-28 weeks of pregnancy to screen out pregnant women with diabetes, and timely guidance should be given to reduce the risk of pregnancy. Standardized and reasonable obstetric examination during pregnancy can timely detect pregnancy complications, fetal abnormalities, etc., and provide timely intervention to ensure the safety of mothers and children.