The prevalence of autism spectrum disorder (ASD) has progressively increased over the past few decades, with estimates now at 1 in 68 individuals affected. Research continues to work on identifying both the genetic and environmental factors that could lead to autism spectrum disorder. One factor that has been scrutinized is prenatal ultrasounds. As the technology has advanced, the number of ultrasounds that women have during pregnancy has increased substantially during the past several decades, and some argue that the previously established guidelines are no longer applicable.
Now, a new study co-authored by Boston University School of Public Health (BUSPH) researchers has found that the number or duration of abdominal fetal ultrasounds are not associated with future development of autism spectrum disorder (ASD).
The study was published in JAMA Pediatrics.
The study included 420 participants (328 boys, 92 girls) born to mothers who received prenatal care and delivered their baby at the same hospital. Among the participants, 107 had been diagnosed with ASD, 104 with other developmental delays, and 209 were controls with typical development. The researchers examined fetal ultrasound screenshots from the participants. They looked at number and timing of scans, duration of exposure, mean (average) strength (depth, frame rate, mechanical index, and thermal index), and time of Doppler and three- and four-dimensional imaging.
Overall, children with ASD had fewer ultrasound examinations during the first trimester compared to the control group; an average of 5.9 and 6.1 scans, respectively. Moreover, while the there was a statistically significant association between ASD and greater mean depth of ultrasound penetration compared to the control group, the researchers found no association between the number or the duration of the ultrasounds and future development of ASD.