Frequent ultrasound in pregnancy usually has no effect. There is no need to do ultrasound frequently if there is no abnormality during pregnancy, and if there is abnormality, you should do ultrasound under the guidance of your doctor. After pregnancy can do ultrasound examination, ultrasound is through the ultrasound examination of imaging, there is no ionizing radiation and electromagnetic radiation, will not affect the growth and development of the fetus, do ultrasound more often, the general impact is not great. After pregnancy about 5 times to do ultrasound examination, 35-42 days after menopause to do ultrasound to determine whether the uterine cavity is normal pregnancy; 11-14 weeks of pregnancy ultrasound to check the thickness of the fetal nuchal translucent layer; 20-24 weeks of pregnancy four-dimensional ultrasound to check the various organs of the fetus whether there are malformations. Review ultrasound at 28-32 weeks of pregnancy to see if the development of the fetus matches the month of pregnancy; ultrasound at 36 weeks of pregnancy to see the fetus, placenta, amniotic fluid and other conditions. If the fetus has abnormal growth and development during pregnancy, you may need to increase the number of ultrasounds, depending on your pregnancy. After pregnancy, you need to do regular pregnancy checkups, so that any abnormalities can be dealt with in a timely manner.