Reduced structural brain asymmetry during neonatal life is potentially related to autism spectrum disorders in children born extremely preterm.
In extremely preterm infants, less lopsided brains on day-one MRI forecast later autism.
01Research in Context
What this study did
Doctors took brain scans of 66 extremely preterm babies within days of birth.
They measured how much the left and right sides of each brain differed in shape.
Years later they checked which kids had been diagnosed with autism.
What they found
Babies who later got an autism diagnosis had more even, less lopsided brains.
The biggest gaps showed up in areas that handle language.
Less brain asymmetry at birth meant higher autism risk later on.
How this fits with other research
Blanchard et al. (1979) first noticed odd brain symmetry in older autistic kids. Eklöf et al. (2019) now show the same pattern starts right after extremely preterm birth.
Vassos et al. (2023) followed the same babies to age 10. The kids still met autism criteria, but parents saw fewer hand-flaps or repeated phrases than in term-born peers. Brain asymmetry predicted autism, yet day-to-day behavior looked milder.
Kuang et al. (2025) used simple developmental tests at 6–24 months to rule out autism with 93.6 % certainty. Their tool is easier than an MRI, but both studies flag the same very preterm group.
Why it matters
If you serve NICU graduates, ask parents for any neonatal MRI reports. Note if radiologists mention “reduced asymmetry” or “symmetrical hemispheres.” Pair that with routine BSID-III checks at 6, 12, and 24 months. Early red flags let you start social-communication coaching before delays widen.
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02At a glance
03Original abstract
Disruption of the normal patterns of structural brain asymmetry, and in language-related areas, has been reported in individuals with autism spectrum disorder (ASD). We tested the hypothesis that 16 children born extremely preterm (EPT), and diagnosed with ASD at 6.5 years of age (EPT-ASD), would have different patterns of brain structural asymmetry, particularly in language-related areas, to 21 EPT children without ASD and 15 term-born children. They all underwent neonatal magnetic resonance imaging scans at 40 weeks of gestation. ASD diagnoses and the Weschler Intelligence Scale for Children-Fourth Edition, were performed in the EPT children, but not in the term group. Asymmetry indices (AIs) were assessed at three levels: global (hemispheres), lobar (brain lobes), and modular (primary sensorimotor, unimodal, and higher-order association areas). AIs were also assessed in language-related regions and correlational analyses were performed between these AIs and verbal scores. The EPT-ASD group showed reduced structural asymmetry at the modular level, mainly involving the higher-order association cortices and the language-related areas. Predominant positive correlations between language functioning and leftward AIs in the inferior frontal gyrus (opercular) and supplementary cortices, and rightward asymmetry in the angular and supramarginal gyri, were identified in the EPT-ASD group. The overall results suggest that reduced brain structural asymmetry identified during the neonatal period would be a risk factor for the development of ASD in EPT infants. This finding could identify EPT children at risk at an early stage, so that tailored interventions could be used to optimize their functions and quality of life. Autism Res 2019, 12: 1334-1343. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Babies born before the expected date (preterm) are more likely to develop autism, due to abnormal brain development. Compared with children without autism, preterm children with autism did not display the important physical differences between the two sides of their brain that are needed for normal functioning. As this alteration was found just after birth, this information could be used to identify children who are likely to develop autism, so that they can get medical support at an earlier age.
Autism research : official journal of the International Society for Autism Research, 2019 · doi:10.1002/aur.2169