Prolonged exposure to ultrasound in the womb causes brain abnormalities in fetal mice, according to researchers. The finding sounds a cautionary note about the frivolous use of ultrasound for such things as keepsake sonograms, even though the study is not directly applicable to humans.
The study in mice does not mean that use of ultrasound on human fetuses for appropriate diagnostic and medical purposes should be abandoned. Instead, the study warns against its non-medical use. The FDA and the American Institute of Ultrasound Medicine have formally opposed such uses, warning that the effects of repeated ultrasound exposures on human fetuses are not known.