The first day of pregnancy, you need to have an ultrasound to check the fetal bud, fetal heartbeat, blood HCG, progesterone and estradiol. 11-13+6 weeks for NT test and early Down screening test, and to establish a pregnancy file. After 28 weeks, the fetus will be examined every two weeks and a general ultrasound will be done every 3-4 weeks. Monitor the development of the fetus. After 32 weeks, you can have fetal heart monitoring once every 2 weeks, and after 36 weeks, you need to have fetal heart monitoring once a week. For example, if there is abdominal pain, vaginal bleeding, bad fetal heartbeat and other special conditions, you need to review the fetal heartbeat monitoring and ultrasound at any time. Each time period is not absolute, and the doctor will give individualized treatment according to the condition of the pregnant woman.