A new study conducted on mice showed that ultrasound may affect the normal development of brain in yet unborn babies. Researchers found that ultrasounds cause brain abnormalities to babies carried by pregnant lab mice.

However, ultrasounds were not proved yet to have the same effect upon human babies and further trials would be needed. The next step would be to investigate the brain behavior of unborn monkey babies, because monkeys have a more human-like brain.

Scientists from Yale University in New Haven, Connecticut, injected about 335 unborn mice found in their mother's wombs with special markers to track neuronal development. Then researchers exposed mice mothers to ultrasounds and found that a 30 minutes' or longer such exposure causes a certain number of unborn babies' neurons to disperse in inappropriate places of the brain.

Research leader Dr Pasko Rakic stated that "upcoming studies should give us information that will be more directly applicable to uses of ultrasound waves in humans." However, he advised pregnant women to continue having ultrasound scans because this type of testing has been shown to be very beneficial in the medical context. Instead, our study warns against its non-medical use," Dr Pasko Rakic stated.

The effects ultrasounds might have on human brain are still unknown to scientists, but the neurons that migrate to totally wrong places in the unborn children could lead to a wide range of severe diseases. "These disorders range from mental retardation and childhood epilepsy to developmental dyslexia, autism spectrum disorders and schizophrenia," the researchers said.

In response to the study, Dr. Joshua Copel, president-elect of the American Institute of Ultrasound Medicine stated: "Anytime we're doing an ultrasound we have to think of risk vs. benefit. What clinical question are we trying to answer? It may be very important to know the exact dating of pregnancy, it's certainly helpful to know the anatomy of the fetus, but we shouldn't be holding a transducer on mom's abdomen for hours and hours and hours."