Safety and U.S. Regulatory Considerations in the Nonclinical Use of Medical Ultrasound Devices

Ultrasound imaging has been used for medical purposes for over 50 years and has an excellent safety record. Ultrasonic fetal scanning is generally considered safe and is properly used when medical information on a pregnancy is needed. However, ultrasound energy delivered to the fetus cannot be regarded as completely innocuous. Even though there are no demonstrated risks from ultrasound imaging, it can produce effects on the body. Laboratory studies have demonstrated that diagnostic levels of ultrasound can produce physical effects in tissue, such as mechanical vibrations, rise in temperature and cavitation. A number of in vitro and in vivo (animal and human) biologic effects have been reported following exposure to diagnostic ultrasound devices and low intensity ultrasound used for therapeutic purposes. Most public health experts, clinicians and industry agree that exposure of the fetus to ultrasound for nonmedical purposes should be avoided. The U.S. Food and Drug Administration (FDA) supports this position. (E-mail: gerald.harris@fda.hhs.gov)