Large-scale study raises concerns about effects of first-trimester diagnostic ultrasounds

First-trimester diagnostic ultrasounds may put children with a genetic vulnerability to autism at higher risk for severe symptoms if they develop the condition, a study suggests. 

Sara Jane Webb and colleagues evaluated data on 2,644 families included in the Simons Simplex Collection database. The sample included 1,749 children with autism spectrum disorders (ASD) whose profiles contained information on whether or not they had copy number variations (CNV), a risk factor for ASD. Copy number variations are anomalies involving insertions, deletions, inversions, or duplications in areas of the genome. 

The researchers found that: 

• For the entire sample of children with ASD, exposure to diagnostic ultrasound during the first trimester correlated with lower social affective symptoms observed by clinicians but worse restrictive and repetitive behaviors as reported by parents. 

• For children with CNVs, exposure to first-trimester diagnostic ultrasound correlated with lower nonverbal IQ scores. In addition, there was a trend toward more impaired adaptive behaviors as reported by parents and increased repetitive behaviors as observed by clinicians. 

• For male children with CNVs, exposure to first-trimester diagnostic ultrasound was related to lower nonverbal IQ and increased repetitive behaviors as observed by clinicians, as well as trends toward reduced verbal IQ and increased repetitive symptoms as reported by parents. 

• There was no correlation between ASD symptom severity, CNVs, and diagnostic ultrasound exposure during the second or third trimesters. 

The researchers conclude, “These data suggest that heterogeneity in ASD symptoms may result, at least in part, from exposure to diagnostic ultrasound during early prenatal development of children with specific genetic vulnerabilities. These results also add weight to ongoing concerns expressed by the FDA about non-medical use of diagnostic ultrasound during pregnancy.”

Citations

“Severity of ASD symptoms and their correlation with the presence of copy number variations and exposure to fi rst trimester ultrasound,” Sara Jane Webb, Michelle M. Garrison, Raphael Bernier, Abbi M. McClintic, Bryan H. King, and Pierre D. Mourad, Autism Research, September 1, 2016 (online). Address: Pierre D. Mourad, Department of Neurological Surgery, Box 356470, University of Washington Seattle, WA 98195, pierre@apl. washington.edu. 

—and— 

“Prenatal ultrasound tied to autism severity in at-risk kids,” Megan Brooks, Medscape, September 21, 2016.