Has MRI found differences in brains of low birth weight autistic children?

PostedDecember 1, 2025

UpdatedDecember 1, 2025

ByMy Patient Advice

Author: Lucia Alvarez, MSc | Reviewed by: Dr. Rebecca Fernandez, MBBS

MRI in low birth weight autism has become an area of growing interest for researchers and clinicians alike. While MRI findings in autism are well‑documented, specific research focusing on autistic children with low birth weight remains sparse. Nonetheless, early brain-age studies have shown delayed developmental markers in children born extremely underweight, suggesting MRI can reveal subtle deviations in brain maturation for this high-risk group.

Most of the evidence comes from broader autism neuroimaging findings rather than targeted low birth weight studies. MRI in autistic individuals typically shows region-specific structural differences, such as variations in cortical thickness, surface area, and connectivity in areas like the frontal or temporal lobes. These findings provide valuable insights into autism’s neurobiological underpinnings, but more focused MRI studies are needed to clarify how birth complications shape brain differences in autistic children.

Insights from Neuroimaging Research

Here’s an overview of what MRI studies generally reveal in neurodevelopment, and why it matters for low birth weight autistic infants:

Brain-Age Delays in Low Birth Weight Infants

Advanced MRI techniques that estimate a child’s “brain age” have revealed delays in brain maturation in infants born extremely underweight (<1000 g). This suggests that birth weight may directly influence neurodevelopmental timing, which could intersect with autism-related brain development.

Autism-Related Structural Variations

In autistic populations more broadly, MRI studies frequently highlight differences in cortical development, including altered thickness and gyrification, and shifted surface area in key regions associated with cognition and sensory processing. These neuroimaging findings underscore how brain structure and function may diverge in autism.

Connectivity and Microstructural Differences

Diffusion-weighted MRI studies show variations in white matter integrity and connectivity in autistic children, particularly in regions related to language, social processing, and sensory integration.

While direct MRI comparisons in autistic babies born underweight are still limited, emerging neuroimaging methods such as brain-age estimation and connectivity mapping offer promising tools for future discovery in this unique subset, highlighting the growing importance of MRI in low birth weight autism research.

For expert support tailored to developmental profiles that include birth history and neuroimaging insights, visit providers like Autism Detect for personalised guidance and intervention planning.

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to Birth Complications and Low Birth Weight.

Lucia Alvarez, MSc

Author

Lucia Alvarez is a clinical psychologist with a Master’s in Clinical Psychology and extensive experience providing evidence-based therapy and psychological assessment to children, adolescents, and adults. Skilled in CBT, DBT, and other therapeutic interventions, she has worked in hospital, community, and residential care settings. Her expertise includes grief counseling, anxiety management, and resilience-building, with a strong focus on creating safe, supportive environments to improve mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy.

Dr. Rebecca Fernandez, MBBS

Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.