Paracetamol, pregnancy and autism: what the science really shows

US president Donald Trump has claimed that paracetamol (acetaminophen or Tylenol) use in pregnancy is linked to autism in children, urging pregnant women to avoid the painkiller. This announcement has sparked alarm, confusion and a flurry of responses from health experts worldwide. Trump’s comments come in a long line of unsubstantiated claims about the causes of autism, with paracetamol now the latest target.

To understand these claims, we need to examine what autism actually is and why diagnoses have increased. Autism spectrum disorder (ASD) or autism is a complex neurodevelopmental condition affecting social interaction, communication and behaviour. It is not a disease but a lifelong difference in how people experience and interact with the world.

While diagnoses of autism have increased in recent decades, this is largely due to better awareness, broader diagnostic criteria and improved access to assessments. Many people, especially women and those with less typical presentations, were previously missed or misdiagnosed.

Trump’s recent statements have cited mounting evidence linking paracetamol in pregnancy to autism and suggested the Amish and Cuban communities have virtually no autism because they don’t use the drug. However, there are documented cases of autism in both the Amish community and Cuba.

Both communities also use paracetamol, but it’s not used as widely as in the US or UK, say, which might suggest a link between the drug’s use and autism (high use, high autism prevalence; low use, low autism prevalence). However, attributing low rates to paracetamol use ignores the complexities of diagnosis, reporting, healthcare access and cultural or religious stigma in different populations.

A more nuanced picture

The scientific evidence presents a more nuanced picture than the White House statements. A 2025 review, funded by the National Institutes of Health in the US, analysed 46 studies. Twenty-seven of these found a link between paracetamol use during pregnancy and increased risk of neurodevelopmental disorders in children. The review does strengthen the evidence for a potential connection, but importantly, it does not prove that paracetamol causes autism. Other factors – like why women took paracetamol in the first place (infection or fever) – could explain the results.

More reassuring is the largest and most rigorous study to date – a Swedish nationwide analysis of over 2.4 million children. It found no evidence of increased risk of autism in children whose mothers used paracetamol during pregnancy, once family and genetic factors were accounted for.

The study provides strong reassurance that paracetamol, when used as recommended, is an unlikely cause of autism. Another 2025 review similarly showed that taking paracetamol during pregnancy is unlikely to significantly increase the risk of autism in children.

Autism does not have a single, simple cause. It develops through a complex interaction of genetic and environmental factors. While genetics play an important role, no single gene or mutation explains autism on its own. Environmental factors – such as an infection during pregnancy, certain medications, microplastics, advanced parental age, or complications around birth – may also increase risk. However, in most cases, autism cannot be traced back to any one factor alone.

The clinical reality is that paracetamol remains the first-choice painkiller for pregnant women for good reason. Untreated pain and fever in pregnancy can themselves pose serious risks to both mother and baby – increasing the risk of birth defects like spina bifida, cleft lip or palate and heart problems.

Other common painkillers, such as ibuprofen and aspirin, are not recommended in pregnancy unless under medical supervision, as they carry risks to the baby including issues with blood circulation, lungs and kidney development.

The UK’s medicines regulator has reaffirmed that paracetamol is safe to use in pregnancy when taken as directed. There is no evidence that it definitively causes autism and pregnant women should not avoid necessary treatment for pain or fever. Experts agree there’s no need to change existing advice – paracetamol remains safe to use for pain or fever in pregnancy when taken as recommended.

For pregnant women experiencing pain, the NHS continues to recommend trying natural measures first – getting fresh air, drinking water and avoiding screens. But when these don’t work, paracetamol remains the safest pharmaceutical option when taken at the lowest dose for the shortest time necessary.

Ultimately, the paracetamol-autism debate illustrates a familiar pattern: complex science being reduced to political soundbites. Autism is a multifactorial condition shaped by genetics and environment, not a single pill taken in pregnancy.

The overwhelming weight of evidence still supports paracetamol as the safest option for pregnant women when used as recommended. The real danger isn’t the medicine – it’s oversimplified claims that create fear and undermine trust in healthcare.

Dipa Kamdar does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.