Intrauterine effects of ultrasound: Human epidemiology

Ultrasound imaging has been used clinically as an effective diagnostic tool over the past 30 years. In spite of literally millions of examinations, th ere is no verified documented evidence of adverse effects in patients cause d by exposure to diagnostic ultrasound. A number of epidemiological studies of intrauterine ultrasound exposure have been conducted, including several case-control and prospective randomized control studies. In some studies, an association of one or another bioeffect was identified, such as low birt h weight, delayed speech, or increased incidence of left-handedness. Howeve r, with the exception of low birth weight, these findings have never been d uplicated, and the great majority of such studies have been completely nega tive. (C) 1999 Wiley-Liss, Inc.