Sunday, 23 November 2008 13:52
A new study warns, exposure to ultrasound can affect fetal brain development. Head researcher Pasko Rakic, chairman of the neurobiology department at Yale University School of Medicine. Although Rakic says, "Our study in mice does not mean that use of ultrasound on human fetuses for appropriate diagnostic and medical purposes should be abandoned" he did, however add that women should avoid unnecessary ultrasound scans until more research has been done.
The study, funded by the National Institute of Neurological Disorders and Stroke revealed that when pregnant mice were exposed to ultrasound, a small number of nerve cells in the developing brains of their fetuses failed to extend correctly in the cerebral cortex. The paper added that the since the developmental period of these brain cells is much longer in humans than in mice, that exposure would be a smaller percentage of their developmental period. However, the authors also made it clear that brain cell development in humans is also more complex than in mice and with more cells developing, the chances of developmental mishaps could be increased.
In Rakic's study, pregnant mice were exposed to ultrasound for various amounts of time ranging from a total exposure of 5 minutes to 420 minutes. The brains of the newborn baby mice were studied and compared with those of mice whose mothers had not been exposed to ultrasound.
The study of 335 mice concluded that in those whose mothers were exposed to a total of 30 minutes or more, "a small but statistically significant number" of brain cells failed to grow into their proper position and remained scattered in incorrect parts of the brain. The number of affected cells increased with longer exposures.