The question of whether **acetaminophen use during pregnancy can cause Asperger’s syndrome** or other autism spectrum disorders (ASD) in children has been a topic of public concern and scientific investigation. Asperger’s syndrome, now generally classified under the broader category of ASD, involves challenges with social interaction and restricted or repetitive behaviors. Given the widespread use of acetaminophen (also known as paracetamol outside the U.S.) as a pain reliever and fever reducer during pregnancy, understanding any potential risks is crucial.
**Current scientific evidence does not support a causal link between acetaminophen use during pregnancy and Asperger’s or autism spectrum disorders in children.** This conclusion is based on large-scale, well-designed epidemiological studies and reviews by authoritative health organizations.
One of the most comprehensive studies on this topic was conducted in Sweden, leveraging the country’s extensive national healthcare records. This study analyzed data from approximately 2.5 million children born over 25 years, including about 185,000 whose mothers used acetaminophen during pregnancy. The researchers used a sibling comparison design, which is a powerful method to control for genetic and environmental factors shared within families. They compared children exposed to acetaminophen in utero with their siblings who were not exposed. The results showed **no association between prenatal acetaminophen exposure and increased risk of autism, ADHD, or intellectual disability**[1].
This finding is significant because observational studies that do not control for familial factors can sometimes suggest misleading associations. For example, mothers who take acetaminophen frequently during pregnancy might do so because of underlying conditions such as infections or inflammation, which themselves could influence neurodevelopment. The sibling comparison method helps isolate the effect of acetaminophen itself from these confounding factors.
Major health authorities, including the **World Health Organization (WHO)** and European regulatory agencies, have reviewed the evidence and maintain that acetaminophen is safe for use during pregnancy when taken as directed. The UK Health Secretary has explicitly stated that there is no evidence linking acetaminophen use in pregnancy to autism in children[1].
It is important to note that **fever during pregnancy, if left untreated, can pose risks to fetal development**. Fever is a sign of infection or inflammation, which can affect the developing brain. Acetaminophen is often recommended to reduce fever safely during pregnancy, which may actually help reduce potential risks associated with high maternal temperature[1].
In summary, while some early observational studies raised concerns about a possible link between acetaminophen and neurodevelopmental disorders, more rigorous research controlling for genetic and environmental confounders has not found evidence supporting this link. The consensus among experts and health organizations is that acetaminophen, when used appropriately during pregnancy, does not cause Asperger’s syndrome or autism spectrum disorders in children.
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[1] Psychology Today, “The Risk Is Not From Tylenol but Untreated Fevers,” 2025.
