The analysis of sister chromatid exchanges (SCEs) has been long considered to be a very sensitive test in detecting certain types of DNA damages, and is particularly useful for testing external influences on chromosomes such as ultraviolet rays and mutagenic chemicals. In the presence of such influences, sister chromatid exchanges in the different phases of the cell cycle will increase compared to that of controls.

IJ Macintosh and DA Davey's (South Africa) paper in the British Medical Journal in 1970: "Chromosome abberations induced by an ultrasonic fetal pulse detector" was the first paper to suggest a deleterious effect of diagnostic ultrasound on fetal tissues. This raised widespread concern about clinical safety. However subsequent studies by several other centres could not confirm such findings and the conclusions of a harmful effect was withdrawn by the authors 5 years later.

The study of Liebeskind et al in 1979 also indicated that exposure to diagnostic levels of ultrasound insonation for 30 minutes caused increase in SCEs in human lymphocytes and in a human lymphoblast line. The same author however reported no changes in SCEs in a different study. There has been at least a dozen studies that followed which reported no increase in SCEs, some at much higher ultrasonic levels. It was general consenses in the early 1980s that diagnostic ultrasound is safe as far as inducing chromosomal changes are concerned.

Chromosome abberations induced by an ultrasonic fetal pulse detector. IJ Macintosh, DA Davey. Br Med J 1970;4-92.

Sister chromatid exchanges in human lymphocytes after exposure to diagnostic ultrasound. Liebeskind D, Bases R, Mendez F, Elequin F, Koenigsberg M Science 1979 Sep 21 205:4412 1273-5

Back to History of Ultrasound in Obstetrics and Gynecology.