With the invention of b-type ultrasound, the application of b-ultrasound in obstetrics maternity examination is essential, many pregnant mothers have concerns about repeated b-ultrasound, ultrasound examination on the baby in the stomach has an impact? From the application of b-ultrasound to the present, the safety of b-ultrasound has been confirmed. b-ultrasound principle is the use of ultrasound waves propagated in the body, due to the specificity of the various tissues of the body’s differences in ultrasound waves in the interface of the two different tissues to produce reflections, refractions, and other physical characteristics of the probe to accept these signals, so as to imaging, to make judgments. For therapeutic ultrasound, belongs to hundreds – thousands of mW/cm2 above the high-intensity ultrasound, and b ultrasound imaging used for low-intensity ultrasound, obstetric ultrasound used by the ultrasound settings are even lower, so, will not have an impact on the baby, so far, b ultrasound in the clinical application of more than 50 years, and there is no ultrasound caused by the baby’s deformity reports. Moreover, ultrasound is sufficient for routine obstetric examinations because of its ability to visualize blood flow. Of course, ultrasound should not be done without necessity, and in animal studies, excessive ultrasound was indeed found to have an effect on mouse embryos. What does it mean? It means that if an expectant mother takes ultrasound like a meal and does it every day, of course it’s like eating every day, and it’s bound to push up. Therefore, as long as the regular ultrasound checkups are done on schedule, there is no effect on the fetus. Systematic prenatal ultrasonography is important for the systematic screening of fetal anatomy, and ultrasound does not observe and display organ function. And pregnancy is a dynamic process, fetal growth is the same, some organs have been growing and developing, so, regular ultrasound examination is necessary.