The effects of diagnostic ultrasound on sister chromatid exchange frequencies: a review of the recent literature.

The precise nature and significance of SCEs are still not understood. It is clear that SCE analysis is a sensitive means of detecting genotoxic agents, and that SCEs are correlated with mutation, in vitro transformation, and cancer. SCEs, as all other short-term assays, are subject to false positives and false negatives. Therefore, it is possible that even if ultrasound induces SCE, the effects may not be deleterious, although the reverse could be true as well. The majority of studies have not observed SCE induction after exposure to diagnostic ultrasound, however two positive responses have been reported. Such discrepancies cannot be explained until investigators adopt a uniform protocol for ultrasound exposure. The currently widespread use of ultrasound in antepartum diagnosis, and the rate at which its use increases, argue strongly for additional research into its potential for genetic toxicity.