With the invention of b-type ultrasound, the application of b-ultrasound in obstetrics and gynecology is essential. Many pregnant mothers have concerns about the psychology of multiple b-ultrasound, does ultrasound have an effect on the baby in the tummy? From the application of b-ultrasound to the present, the safety of b-ultrasound has been confirmed. b-ultrasound is based on the principle of using ultrasound to propagate in the body, and due to the specific differences of various tissues in the human body, ultrasound produces physical properties such as reflection and refraction at the interface of two different tissues, and the probe accepts these signals to image and make judgments. For therapeutic ultrasound, it is a high-intensity ultrasound of several hundred to several thousand mW/cm2 or more, while b ultrasound imaging used for low-intensity ultrasound, the amount of ultrasound settings used in obstetrical ultrasound is even lower, so it will not affect the baby, and so far, b ultrasound has been used in clinical applications for more than 50 years, and there are no reports of baby deformities caused by ultrasound. And ultrasound is sufficient for routine obstetric examinations because of its ability to see blood flow. Of course, do not do ultrasound without necessity, and in animal tests, excessive ultrasound was indeed found to have an effect on the embryos of mice. What does that mean? It means that if the pregnant mother treats the ultrasound like a meal and does it every day, of course, it is like eating every day and will definitely cause problems. Therefore, as long as the regular ultrasound checkups are done on schedule, there is no effect on the fetus. Systematic prenatal ultrasound is important for the systematic screening of fetal anatomy. b ultrasound does not observe and show the function of organs. The fetal growth is also a dynamic process, and some organs are always growing and developing, so it is necessary to have regular ultrasound examinations.