US Food and Drug Administration (FDA) guidelines on the use of ultrasound in the first trimester of pregnancy have received a boost from a new study that links its use to increased autism severity
The study, by researchers at University of Washington (UW) Medicine, UW Bothell and Seattle Children’s Research Institute, is published in the journal Autism Research.
The researchers looked at the variability of symptoms among children with autism, not at what causes the condition. They found a link between exposure to diagnostic ultrasound in the first trimester and increased autism symptom severity.
The strongest link was found among children with certain genetic variations associated with autism — seven percent of the children in the study were found to have these variations. FDA guidelines currently recommend that diagnostic ultrasound only be used for medical necessity.
I believe the implications of our results are to bolster the FDA guidelines.
Said corresponding author Pierre Mourad, a UW professor.
Mourad said the results are about the first trimester of pregnancy — data looking at the effect of ultrasound on the second and third trimester showed no link.
The researchers used data from the Simons Simplex Collection autism genetic repository funded by the Simons Foundation Autism Research Initiative (SFARI). The data was derived from 2,644 families among 12 research sites across the US.
There has been a real struggle in why there are so many kids with autism. Where does this disorder develop from? How do kids get autism? And the second question is why are kids with autism so different from each other? This study really looks at the second question. Within kids with autism, what are some of the factors that may result in a child having a good outcome or higher IQ or better language or less severity versus a child who maybe takes more of a hit and continues to struggle throughout their lifespan?
Said lead author Sara Webb, UW Medicine researcher in psychiatry and behavioural sciences.
Webb said the research team approached their work based on a three-part model explaining variability in kids with autism. The first is a genetic vulnerability to the disorder; the second is an outside stressor; and the third implies that the outside stressor has to impinge on a kid at a certain time.
Webb said a number of outside stressors have been proposed and investigated in autism. This study looked at only one of them — ultrasound.
As a mother of two, Webb said given what she knows now, she would not have ultrasound in the first trimester unless there is a medical necessity and that includes knowing how far along the pregnancy is.
If we can figure out this information in any other way, I would go with that. It’s always worth considering that when we do medical procedures, there are great benefits but also risk.
Mourad said he and his colleagues now intend to look more closely into links between ultrasound and autism severity, as well as the possibility — thus far not shown — that ultrasound exposure could contribute to autism incidence.