Frequent ultrasound during pregnancy has no effect on the fetus. Ultrasound is a Doppler ultrasound examination, which is non-invasive. The role of ultrasound during pregnancy is very important. By doing ultrasound, we can understand the size and position of the fetus, and more importantly, we can understand the growth and development of the fetus. Color ultrasound is a very common test, and there is no radiation and no increased risk of fetal developmental abnormalities. During pregnancy, 5-6 ultrasounds are needed, and if there are special circumstances, the number of examinations will be increased as appropriate.