How does parental age affect genetic risk for autism?

PostedNovember 19, 2025

UpdatedNovember 19, 2025

ByMy Patient Advice

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

Studies have consistently shown that parental age, particularly advanced age, can influence the likelihood of a child being diagnosed with autism. Both maternal and paternal influence play a role, but the effect is often more pronounced in older fathers due to increased chances of new mutations during sperm development.

As people age, the risk of genetic changes in reproductive cells increases. In fathers, this may lead to spontaneous mutations, called de novo mutations, that contribute to autism traits in their children. In mothers, older age is more commonly associated with complications during pregnancy, which can also affect neurodevelopment when combined with genetic risk. While age alone does not cause autism, it is considered one of several contributing factors that can shape autism heritability and risk levels.

Why Parental Age Matters in Autism Research

Here are two key insights into how parental age affects autism risk:

Greater mutation load in older fathers

As men age, the number of cell divisions needed to produce sperm increases, raising the likelihood of copying errors in DNA. These de novo mutations may not exist in either parent’s genetic code but can affect how a child’s brain develops, increasing susceptibility to autism.

Maternal age linked to broader developmental risk

While fewer direct mutations are passed from mothers, advanced age in pregnancy is associated with higher rates of birth complications, including low birth weight and preterm delivery. These factors can influence brain development when paired with inherited risk.

Understanding the role of parental age in autism helps families make informed decisions about timing and early monitoring. Visit providers like Autism Detect for personal consultations and further guidance on screening and support.

For a deeper dive into the science, diagnosis and full treatment landscape, read our complete guide to Genetic Influences.

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.