Greater mean penetration depth of prenatal ultrasound was associated with increased incidences of autism spectrum disorder and developmental delay, according to findings from a study published in JAMA Pediatrics.
Gestational age, total time of exposure, mean depth, frame rate, and total time using 3-dimensional and 4-dimensional imaging were obtained from medical records for patients with autism spectrum disorder (n=107) and compared with the same information for patients with developmental delay (n=104) and typical development controls (n=209).
Among the participants with autism spectrum disorder, mean depth of scan was greater in the first trimester than in the developmental delay group, and was greater in the first and second trimesters than in the typical developmental groups. No other statistical differences among groups were found for the timing of the first ultrasonic scan, total number of scans, frame rate, or total time of exposure.
“Our study demonstrated no increase in the number of prenatal scans or duration of ultrasound exposure in children with later [autism spectrum disorder] compared with controls with developmental delay or typical development,” the researchers wrote.
They also noted a possible mechanism of injury to the fetal brain from mechanical neuronal perturbation and/or hyperthermia, suggesting, “Use of greater depth ultrasonography may be more likely to alter subependymal or germinal matrix cell migration rather than the more superficial cerebral cortical cells of the developing brain.”
Rosman NP, Vassar R, Doros G, et al. Association of prenatal ultrasonography and autism spectrum disorder [published online February 12, 2018]. JAMA Pediatr. doi:10.1001/jamapediatrics.2017.5634