Autism : The impact of in utero environmental factors
- Spectrum Stars
- Mar 16
- 3 min read
Updated: Jun 16
Article by Cassandre Rogeret for Handicap.fr on March 16th, 2025
New Insights into the Origins of Autism
A new study published in the medical journal Journal of Medical Genetics, conducted by French researchers, offers a revised understanding of this neurodevelopmental disorder (NDD), the cause of which remains mysterious. Could this be a promising lead for the 700,000 people affected by autism in France?
Questioning the Direct Link Between Genetics and Autism
“For decades, research on autism spectrum disorders (ASD) has focused on genetic approaches (‘Autism Origins: Genetics, a Key Factor’), overlooking a fundamental element: the impact of in utero environmental factors,” explain the study’s main authors, Yehezkel Ben-Ari and Étienne Danchin. They point out that “many affected children do not present any identifiable genetic abnormality,” challenging the hypothesis of a direct link between genetics and autism. Furthermore, they argue, “the approaches used to demonstrate this link are questionable and depend heavily on an environment that is too often ignored.”
Numerous Non-Genetic Hereditary Mechanisms
In his book The Inclusive Synthesis of Evolution: Inheritance Beyond the Selfish Gene, Étienne Danchin, a CNRS research director at the “Evolution and Biological Diversity” laboratory at Paul Sabatier University in Toulouse, highlights that for over two decades, “numerous discoveries have shown that many non-genetic mechanisms of inheritance exist.” Thus, “the fact that autism appears to be passed from parents to children does not necessarily mean the disorder has a genetic origin,” he asserts.
Underestimated Environmental Risks During Pregnancy?
The study’s authors emphasize that a child’s brain development can be disrupted by various biological, epigenetic, and environmental factors starting at conception. Maternal viral or microbial infections, stress, prenatal inflammation, or hormonal signals can alter key biological development processes and trigger neuronal anomalies responsible for autism and other neurodevelopmental disorders (NDD), they explain. “Exposure to toxic substances, such as certain pesticides or medications taken during pregnancy, also appears to play a major role.”
Improving Care Through AI?
Given these findings, the study stresses the need to “reconsider the purely genomic approach to autism.” Similarly, care practices must evolve. “Artificial intelligence analysis of data routinely collected in maternity wards could help identify, from birth, babies at risk of ASD, opening the door to early psychoeducational interventions that could mitigate symptoms and significantly improve children’s quality of life.”
“A Multifactorial Disorder Requiring an Interdisciplinary Approach”
“It’s time to consider autism as a multifactorial disorder, requiring an interdisciplinary approach and close monitoring of environmental factors from pregnancy onward,” urges Professor Yehezkel Ben-Ari, a neuroscientist. By incorporating these new insights, research is, in his view, “opening up unprecedented opportunities” for supporting individuals with autism and their families. “Earlier detection, better understanding of brain maturation, and identifying how various pathological factors disrupt this maturation are key to effective intervention,” emphasize the French scientists.
A Cohort Study to Identify the Role of Environmental Factors
As a reminder, the Marianne cohort, launched in 2023 by the French Ministries of Research and Disabilities, aims to determine the role of environmental factors (pollution, pesticides, endocrine disruptors, etc.) in autism and neurodevelopmental disorders (Autism: Study to Determine the Role of the Environment). This research project, backed by a €6 million budget, seeks to follow 1,700 pregnant women and their families from pregnancy through childbirth and up to the child’s sixth birthday. This “unique, anonymous, and confidential” follow-up will include regular appointments with social and medical professionals, questionnaires, developmental monitoring by a psychologist, biological sampling, and more. Final results are expected in eight years.
