If studies on pregnant mice also apply to humans, exposing a pregnant mother to ultrasound for over 30 minutes could adversely affect the baby’s brain development, say scientists from Yale University, USA. They found that some nerve cells did not make their way to the correct parts of the developing brain.
You can read about this study in Proceedings of the National Academy of Sciences.
The scientists said that their results call for further investigations in larger and slower-developing brains of non-human primates and comprehensive epidemiological studies in humans.
However, head researcher, Dr. Pasko Rakic, added that if he had a daughter and she was pregnant he would still advise her to have an ultrasound for medical reasons.
The scientists stressed that mice and humans are very different. Just because baby mice seemed to be affected does not mean humans are. The period during which cells migrate to specific parts of the developing pain is much longer for humans than for mice. It is possible that 30 minutes of ultrasound has a much bigger impact on a mouse’s developing brain than a human’s. In order to see what the effect may be on humans we would need to carry out similar tests on animals that are more similar to humans, the researchers said.
This study may persuade many doctors and pregnant women to carry out ultrasound for medical reasons only, and not for entertainment.
There have been studies which showed repeat ultrasounds are safe for humans. There was one in 2004, carried out in Australia, which included over 2,700 children. The children were followed up at the ages of 2, 3, 5 and 8 years. No significant adverse effects were found.
Most ultrasounds on pregnant women do not last more than 20 minutes. Current guidelines for pregnant mothers state that the ultrasound settings should be as low as possible to get a diagnosis.
Department of Neurobiology at Yale University School of Medicine
Written by: Christian Nordqvist
Editor: Medical News Today