Research from the Barwon Infant Study has provided key insights into how maternal health and environmental exposures – such as maternal infections, obesity, gestational diabetes, medication use, and exposure to environmental chemicals – may increase autism risk in children.
Autism cases are rising globally
Autism is characterised by repetitive behaviour patterns, challenges with social interactions, and cognitive differences which persist as one ages, and potentially impact one’s quality of life.
Autism prevalence is increasing globally. The Barwon Infant Study recently reported the highest autism incidence observed in any general population study to date (Love et al., 2025, under review).
The rise of autism can be partially attributed to diagnostic expansion and advocacy efforts; however, the interplay between genetic predisposition and modern environmental exposures may be driving the true increase in incidence.
According to research lead Chloe Love, there is currently limited longitudinal information on autism development in pregnancy and early life. “Given the increase of autism incidence, there’s an urgent need to understand what’s happening,” she said.
Literature review builds picture of how prenatal environmental exposures contribute to autism
The Barwon Infant Study is a collaboration between IMPACT, Barwon Health, the Murdoch Children’s Research Institute, and the Florey Institute of Neuroscience and Mental Health. Researchers consolidated the latest evidence on prenatal risk factors for autism and examined their biological mechanisms.
“What we understand about autism development is that it’s a combination of genetic and environmental contributors,” said Love.
“Through this literature review, we’ve sought to collate existing research on environmental factors during pregnancy that might influence the likelihood of a child developing autism and explore potential underlying biological pathways.”
“There are some risk factors that are better understood than others. For example, we know that obesity, gestational diabetes and exposure to certain plastics and chemicals, have been associated with increased risk of a child developing autism.
“Environmental exposures rarely happen in isolation. If you think about environmental chemicals, it’s unlikely we’re ever exposed to just one type of plastic or chemical. We’re exposed to many chemicals, and the effect it has differs depending on the individual and community, so we need to understand which populations might be more susceptible to certain environmental exposures.”
The research also looked at key biological mechanisms underpinning these maternal risk factors, including inflammation, mitochondrial dysfunction, oxidative stress, hormonal imbalance, and gut microbiome changes.
The review explored how these underlying pathways may interact, highlighting the need for more large-scale epidemiological research that identifies causal pathways and intervention targets.
“We want to understand what changes during pregnancy and early childhood might influence a child’s risk of developing autism,” Love said.
“For example, differences in gut bacteria populations during pregnancy and early childhood might help determine whether a child is more likely to receive an autism diagnosis. Identifying potential biomarkers could enable early intervention and help us create personalised support approaches for autistic children.”
Opportunities for healthcare providers to refine prenatal care strategies
The new findings give mothers a better understanding of how maternal health and environmental exposures may impact foetal neurodevelopment.
Healthcare providers can work with mothers to refine prenatal care strategies and offer targeted guidance on managing infections, metabolic conditions, and medication use during pregnancy.
“By opening pathways for early intervention strategies, we can potentially reduce the prevalence of autism and improve long-term developmental outcomes,” Love said.
She added that public health policymakers can also use the findings to reduce exposure to particular prenatal risk factors.
“Many exposures to plastics and chemicals are beyond individual control. Policy changes are needed, and this research provides evidence to inform policymakers about potential risks.”
Recent research from The Florey Institute of Neuroscience and Mental Health found that higher levels of bisphenol A (BPA), a plastic commonly used in food packaging, were detected in urine samples taken from women pregnant with boys later found to have autism. This published research is part of the material that will be reviewed at the Global Plastic Treaty meeting led by the United Nations Environmental Protection Agency.
Review highlights importance of raising community awareness about maternal health and its impact on childhood neurodevelopment
Many in the neurodiverse community see autism as a difference to celebrate rather than a condition to cure. This is a valuable perspective, but it is crucial to recognise that it does not preclude seeking an improved understanding of autism development.
A key objective of the BIS research program is to investigate the biology of autism to improve outcomes across the life course, from foetal life onwards.
Future research will investigate how diet, nutrition, the gut microbiome, and environmental exposures during pregnancy and early childhood influence autism risk and development, while also assessing probiotics and dietary interventions as potential therapeutic approaches.
