Intrauterine ultrasound

Creating an image of the developing fetus within the uterus by means of measuring the vibrations returned when a device emits high-frequency sound waves. Ultrasound imaging has been done during pregnancy for over three decades. It has proved to be a very useful and very effective diagnostic procedure. A number of epidemiological studies of intrauterine ultrasound exposure have been done to look at its safety. These include studies with a highly sophisticated research design (such as case-control and prospective randomized control studies). The great majority of the studies have been completely negative. Although an occasional study has found diagnostic ultrasound to be associated with one or another effect (such as low birth weight, delayed speech, or an increased incidence of left-handedness), these findings have never been duplicated (except for low birth weight) in any other study. In spite of literally millions of examinations, there is no verified documented evidence of any adverse effects caused by exposure of the embryo or fetus to diagnostic ultrasound. (Reference: Ziskin MC. Intrauterine effects of ultrasound: Human epidemiology. Teratology 59:252-260, 1999.) There is thus no convincing evidence for any danger from diagnostic ultrasound during pregnancy.