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Here’s what experts say about the link between maternal infections and increased risks of autism in children.
Our understanding of autism has evolved significantly since the term was first introduced in 1911, with autism spectrum disorder (ASD) today not generally considered a ‘disease’ or ‘disease’. , according to the UK NHS, but rather as a set of traits. which vary considerably in type and severity.
Yet despite this progress, scientists are still struggling to understand many aspects of this disease.
This includes underlying causes that contribute to autism or increase the likelihood of its occurrence, although current research primarily points to a combination of genetic and environmental factors.
One such factor is infection during pregnancy, such as influenza, which has been extensively studied in animal and human models.
Although this link is not necessarily causal, meaning that getting the flu during pregnancy does not guarantee that a child will develop autism, research indicates that such infections could be a contributing factor.
Does having the flu during pregnancy lead to autism?
“Our work suggests that women who have febrile episodes, who have high antibody titers up to herpes simplex type 2, who report influenza and have documentation of influenza, are all at greater risk. high of having children who will subsequently be diagnosed with ASD,” Dr Ian Lipkin, director of the Center for Infection and Immunity at Columbia University, told L’Observatoire de l’Europe Health .
Lipkin was the lead author of a study exploring the potential link between getting the flu during pregnancy and the risk of autism in children.
The study focused on laboratory-confirmed cases of influenza, rather than relying solely on survey responses or medical records, and found evidence of an increased risk of ASD when diagnosed with influenza in the laboratory was accompanied by self-reported serious symptoms.
“None of this is really surprising,” Lipkin said. “I mean, we tell women not to drink during pregnancy, not to take certain medications during pregnancy, not to smoke during pregnancy, so why would we be surprised if another environmental factor isn’t also important for compromising normal fetal development?
The authors said that if infections contributed to an increased risk of autism, it might not be due to the virus itself but rather the response of the mother’s immune system and the inflammation it triggered.
To better understand what happens to the fetus when the mother contracts an infection leading to autism, researchers studied animal models.
Dr. Irene Sanchez Martin, a postdoctoral researcher at Cold Spring Harbor Laboratory in the United States, recently presented results from her ongoing animal study that examines how inflammation during pregnancy may contribute to neurodevelopmental disorders in children.
Her research, she told L’Observatoire de l’Europe Health, was carried out in mouse models and found that maternal immune activation (MAI) during pregnancy is linked to behavioral outcomes similar to which could be translated as autism in humans.
“We cannot say that a mouse is autistic because it is a different syndrome, but it can move certain behaviors, abnormalities, which can be associated with neurodevelopmental disorders, which are usually the autism as well as schizophrenia,” she explained.
Research has also focused on studying the immediate effects of exposing pregnant mice to viruses, which Sanchez Martin said could be equivalent to approximately the first trimester in humans.
It showed that once the mother’s immune system was activated after simulating infections, early signs of embryo developmental deficits appeared, even within 24 hours of exposure.
Interestingly, the developmental deficits were mainly present in male embryos rather than females, she said.
“Inflammation, not the specific infectious agent”
Although Sanchez Martin pointed out that these results may not be fully transferable to humans due to the use of mouse models, she added that they could shed light on elements that help explain the factors leading to autism, since studies on mice allow embryos from the same mother to be compared.
The results showed that disruptions to the fetus’s environment, such as amniotic fluid or the placenta, could explain why some were at higher risk of developing abnormalities.
“Basically, it makes us understand that it is inflammation that is the factor associated with these problems,” Sanchez Martin said.
Lipkin also added that “high levels of cytokines associated with inflammation” were common in women who have children who were later diagnosed with autism.
“So we think it’s about the inflammation, not the specific infectious agent, and there are many ways to trigger them,” he said.
1. Could you please tell us about some of the key findings and implications of your recent research on the link between maternal infections and the increased risk of autism in children?
Dr. Lipkin: Certainly. Our study found that women who experience laboratory-confirmed cases of influenza during pregnancy, coupled with self-reported serious symptoms like fever, are at a higher risk of having children diagnosed with autism spectrum disorder (ASD). We also found that factors such as high levels of antibodies to herpes simplex virus type 2 and other infections can also increase the risk. While this doesn’t necessarily mean that getting the flu during pregnancy directly causes autism, it does suggest that inflammation and immune responses can play a role in fetal development and potentially contribute to the development of ASD.
2. Expanding on that, what specific immune responses or inflammatory mechanisms do you believe might be involved in this link?
Dr. Sanchez Martin: Our research in mouse models has shown that maternal immune activation (MAI) can trigger early embryonic abnormalities, particularly in male offspring, which could potentially lead to neurodevelopmental disorders like autism. We’ve observed changes in gene expression and alterations in brain structure and function that suggest that these effects may be mediated by inflammatory responses. It’s important to note, however, that these results are from animal studies and may not translate directly to humans, but they do provide insights into potential mechanisms that could be explored further.
3. What are some challenges or limitations in studying this link between maternal infections and autism risk, and how are you addressing them in your research?
Dr. Sanchez Martin: One challenge is the complexity of the human immune system and the many factors that can influence it during pregnancy. Our studies in mouse models allow us to control some of these variables, but they don’t fully reproduce the human experience. Another challenge is the difficulty of gathering accurate data on infections during pregnancy and the development of ASD in children. To address this, we’re using robust methods to track infections and their immune responses, as well as long-term follow-up of study participants to better understand the developmental
