An estimated 30% of individuals who have autism are known to have a genetic abnormality. Another 20% of cases are due to recognised disease, and for the remaining 50% no cause has been determined. With this in mind, scientists have been investigating potential causes, including the idea that there could be a link between autism and the use of ultrasounds during pregnancy.
There’s been a steady increase in the prevalence of autism in the last few decades and according to the CDC as many as one in 68 people now fall somewhere of the autism spectrum. During this timeframe, we’ve seen a rise in the number of ultrasound exams being carried out on pregnant women. Research has suggested that the two may be connected; although this has never been proved by scientists.
A new study has found that, although there seems to be no link between the frequency of ultrasounds and autism in children, there may be a connection with it and the use of deep ultrasound waves throughout the first and second trimesters. Author of the study, Dr N. Paul Rosman, noted that although this study doesn’t prove that deep ultrasound waves cause autism, it does show a strong correlation between the two.
“Depth of penetration has to do with the distance between the ultrasound transducer (probe) on the skin and the point at what you’re looking at on the ultrasound,” said Dr. Jodi Abbott, a co-author and physician at the Boston Medical Center. She added that the depth of penetration “varies based on the size of the woman and the amount of tissue that she has on her belly between the transducer and the foetus. This is not something a woman can control”.
Dr Rosman also said that it would be necessary to carry out further research to verify the findings of this study. If future research supports the results, it’s believed that the link between ultrasounds and autism could be to do with their impact on foetal brain development. “The cells that give rise to the mature brain originate deep within the brain and migrate outward to form the mature cerebral cortex,” he said. “They do this in a very orderly fashion — one generation of cells following another.”
Dr. Marvin Ziskin, a professor of radiology and medical physics at Temple University’s School of Medicine, who was not involved in the study, commented: “Unfortunately, the authors do not appear to know what is meant by the ultrasound penetration depth. It does not relate to the amount of ultrasound entering the body.”
“The factors that determine the amount of ultrasound entering the body, and what would affect the foetus, are the mechanical index, the thermal index, and ultrasound power and intensity, for which no significant differences were found. The amount of ultrasound imparted into pregnant patients has no association with autism spectrum disorder.”