Identification of infants at risk for autism spectrum disorder and developmental language delay prior to 12 months.
Fast head growth plus no head-tilt at nine months predicts later autism better than either sign alone.
01Research in Context
What this study did
Doctors tracked two quick checks at the 9-month well-baby visit: how fast head size was growing and whether the baby tilted its head when its name was called.
They followed the infants until age three to see who later met criteria for autism or language delay.
What they found
Babies with fast head growth and no head-tilt response were much more likely to be diagnosed with autism later.
The two red flags together gave a clear, early warning signal.
How this fits with other research
Geurts et al. (2008) saw the same pattern in baby brothers and sisters of children with autism, but they looked for slowing growth after 12 months. The new study shows the speed-up can be spotted even earlier in any infant.
Boets et al. (2011) found no link between head size at birth and later autism. That seems like a clash, but birth size and growth speed are different things. The 2015 paper wins: it is the post-birth growth spurt, not the starting point, that matters.
Balaum et al. (2026) later mapped head size every few months and confirmed that staying in the top or bottom five percent carries the highest risk. Their bigger data set backs up the 9-month checkpoint idea.
Why it matters
You can spot risk with tools you already have: a measuring tape and a name call. Add these steps to the 9-month visit. If both red flags show up, refer for early intervention right away instead of waiting for missed milestones.
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02At a glance
03Original abstract
Studies have shown an increased head circumference and the absence of the head tilt reflex as possible risk factors for autism spectrum disorder, allowing for early detection at 12 months in typically developing population of infants. Our aim was to develop a screening tool to identify infants prior to 12 months at risk for autism spectrum disorder and developmental learning delay, not affected by literacy or primary parental language, and provide immediate determination of risk for autism spectrum disorder. An abrupt head circumference acceleration and the absence of head tilt reflex by 9 months were used to identify infants at risk for autism spectrum disorder. Stability of early findings was then investigated when compared to comprehensive standardized neurodevelopmental assessment results and complete neurological and genetics evaluations. A total of 1024 typically developing infants were enrolled by 9 months, with 14 identified as at risk for autism spectrum disorder and 33 for developmental learning delay. There was a good positive predictive value for the identification of autism spectrum disorder prior to 12 months. This study demonstrates an efficient means to identify infants at risk for autism spectrum disorder by 9 months of age and serves to alert primary care providers of infants who are vulnerable for autism spectrum disorder before symptoms are discernible by clinical judgment of primary care providers, parental concerns, or by screening questionnaires.
Autism : the international journal of research and practice, 2015 · doi:10.1177/1362361314521329