Frequent ultrasound generally does not affect the fetus, and this is a relatively safe screening program during pregnancy. Color ultrasound belongs to ultrasound, there is no ionizing radiation, electromagnetic radiation, it is a kind of sound wave conduction, there is no harm to the health of the pregnant woman herself and the fetus, and it will not cause radiation to the fetus. It is safer to do color ultrasound during pregnancy. 6~7 times of color ultrasound checkups can be done under normal circumstances after pregnancy, and the number of color ultrasound checkups will be increased accordingly if there are abnormalities after pregnancy, such as preeclampsia, placenta praevia, and intrauterine anoxia. It is recommended to choose a regular hospital for maternity checkups, which items to check after pregnancy, specific to consult the doctor, both to ensure the safety of the mother and child, but also to avoid excessive diagnosis and treatment.