Is maternal age over 40 a threshold for higher autism risk? 

The question of whether maternal age 40 and autism risk are closely linked has become increasingly relevant as more women give birth later in life. Studies suggest there may be an age threshold, with 40 often cited as the point where autism risk begins to rise more noticeably. But is this a strict cut-off, or part of a broader trend? 

Research in epidemiology shows that as maternal age increases, so too does the chance of certain genetic mutations and obstetric complications. This could help explain the observed risk increase for autism in children born to older mothers. However, it is not a guarantee. While there is a measurable association between maternal age 40 and autism risk, it is only one of many influencing factors, as genetics, environment, and prenatal health also play important roles. 

What the data tells us 

Here’s how maternal age 40 and autism risk may interact based on current research: 

A gradual, not sudden, increase  

While 40 is often cited as an age threshold, risk does not rise sharply at this age. Instead, studies show a steady risk increase beginning in the mid-30s and continuing upward. 

Insights from epidemiological studies  

Large-scale epidemiology data supports the link but highlights that age alone is never the sole cause. It is part of a broader, multi-layered risk profile. 

Visit providers like Autism Detect for personal consultations to understand how maternal health and sensory processing may affect your child’s development and how to support effective sensory regulation and comfort. 

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to Advanced Parental Age.

Hannah Smith, MSc

Author

Hannah Smith is a clinical psychologist with a Master’s in Clinical Psychology and over three years of experience in behaviour therapy, special education, and inclusive practices. She specialises in Applied Behavior Analysis (ABA), Cognitive Behavioural Therapy (CBT), and inclusive education strategies. Hannah has worked extensively with children and adults with Autism Spectrum Disorder (ASD), ADHD, Down syndrome, and intellectual disabilities, delivering evidence-based interventions to support development, mental health, and 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.