US Health Secretary Robert F. Kennedy Jr. is reportedly set to announce a link between autism and a popular over-the-counter painkiller, leading to renewed public interest in the topic. The drug is known as Tylenol and acetaminophen in the US and paracetamol in the UK.
Here’s what the current research and medical guidelines say about using this medication during pregnancy.
Research on Acetaminophen and Autism
The scientific community has conflicting findings, and there is no firm evidence to prove a causal link between prenatal acetaminophen exposure and autism.
- A 2024 study in Sweden, which included nearly 2.5 million children, found no causal link between the drug’s use during pregnancy and neurodevelopmental disorders like autism or ADHD.
- In contrast, a 2025 review of 46 earlier studies suggested a possible link between prenatal exposure to acetaminophen and an increased risk of these conditions. However, the researchers from institutions like Mount Sinai and Harvard stressed that their findings do not prove the drug caused the outcomes. They pointed out that other factors, such as the mother’s genetics, health, or other medications, could be the actual cause.
Medical Guidelines and Risks
Despite the ongoing research, major medical organizations continue to recommend acetaminophen as the first-line medication for pain and fever during pregnancy.
- The American College of Obstetricians and Gynecologists (ACOG) and Britain’s Royal College of Obstetricians and Gynecologists both advise pregnant women to use acetaminophen as needed. They also warn against the use of nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen in the third trimester due to the risk of birth defects.
- The risks of leaving a fever untreated during pregnancy can be significant. Unmanaged maternal fever and pain have been linked to an increased risk of birth defects, including heart and neural tube defects, as well as preterm birth and miscarriage. For the mother, untreated fever and pain can lead to high blood pressure and other health issues.
ACOG advises pregnant women to always consult their doctor before taking any medication.
Why the Controversy?
The potential link between acetaminophen and autism has become a major legal issue.
- Hundreds of lawsuits have been filed against retailers by parents and autism activists in the US. They claim the companies failed to warn consumers that the drug could cause ADHD or autism.
- In December 2023, a US federal judge dealt a significant blow to these lawsuits, barring expert witnesses from testifying because their claims lacked scientific evidence. The judge later dismissed all federal cases in August 2024, though a US appeals court is scheduled to hear arguments next month on an appeal of that ruling.
