Are maternal infections a recognised environmental factor influencing autism? 

Yes, maternal infections & autism have been widely studied, and certain infections during pregnancy are recognised as environmental factors that may influence autism risk. While not all infections lead to neurodevelopmental differences, high fevers or immune responses during critical periods of pregnancy have been linked to increased likelihood of autism in children. 

The theory is that the maternal immune system, when activated by infection, can release inflammatory signals that cross the placenta and affect brain development. These responses may alter neural pathways during key stages of foetal growth. 

How Maternal Infections May Influence Autism Risk 

Here are two ways maternal infections during pregnancy could impact autism risk: 

Inflammation-related changes in the developing brain 

Immune responses to infections such as influenza, rubella, or even high fevers can affect foetal brain development by increasing cytokine levels. This inflammation can disrupt neuronal growth and connectivity. 

Timing of infection matters 

Infections during the first or second trimester, when major neural structures are forming, may carry a greater risk than those occurring later in pregnancy. Early exposures appear to have stronger associations with developmental outcomes. 

Recognising the role of maternal infections & autism highlights the importance of prenatal healthcare, vaccination, and fever management during pregnancy. 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 Environmental Factors. 

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.