Tylenol use during pregnancy linked to autism? An AIIMS expert unpacks Trump claim

It is a brand name for acetaminophen, or paracetamol, which we use as a pain reliever and a fever reducer. An over-the-counter medication, it is used to alleviate headaches, muscle aches, arthritis and used to manage symptoms of colds and flu.

“Used under medical supervision and within dosage as advised by the doctor, paracetamol is safe for use during pregnancy. Every drug should be taken based on the severity of fever and infection as well as consultation with the doctor. It should not be taken casually during pregnancy. Indians tend to self-medicate with paracetamol at the slightest hint of a body ache,” says Prof Sheffali Gulati, faculty in-charge of the child neurology division in the department of paediatrics, AIIMS, New Delhi.

And what is autism?

It is a condition related to brain development of a child that affects their social behaviour, interaction and communication with the people around them. The condition also includes limited and repeated patterns of behaviour.

Can taking the drug during pregnancy be linked to the development of autism?

According to Prof Gulati, there is no science-based evidence or research till date which shows that paracetamol, when taken by pregnant women as advised by the doctor, is a causative factor of autism.

“This is not a simple condition and cannot be attributed to a single factor. It depends on genetic factors (related to genes) or epigenetic factors (environmental influences and behaviour that modify how genes are expressed, a process by which the information encoded in a gene is turned into a body function). These external factors include diet, exercise, early-life experiences, nutrition status, exposure to pesticides and air pollution,” says Prof Gulati. There are several stressors in a child’s environment and each child could react differently to them.

What about existing evidence on Tylenol use and pregnancy?

Dr Gulati says many observational studies have found associations but none of them could establish direct causality. There were far too many confounding factors, which suppressed conversations on the real causes of autism among children. She cites the latest research by Karolinska Institutet, Stockholm, last year which found that paracetamol use during pregnancy was not associated with children’s risk of autism, ADHD (attention deficit hyperactivity disorder) or intellectual disability.

“This study analysed data from 2.48 million children born in Sweden between 1995 and 2019. In initial analyses, which did not account for shared familial factors, researchers found a slight increase in the risk of autism and ADHD among children whose mothers used paracetamol during pregnancy. But in a sibling controlled analysis, which compared siblings, the same association was not found. The mother would have been taking paracetamol in all her pregnancies but all her children weren’t exposed to the risk of developing autism. In other words, the drug cannot be held up as a trigger because clearly other factors are at play,” she explains.

What does current research on autism lack the most?

Dr Gulati believes that any understanding of how genes impact children should begin with adolescent girls in the cohort.

“They will become mothers in the future, so their nutrition status, their vaccine status, their diet, lifestyle, environment and all that shapes them need to be studied to understand what could impact their progeny,” she says.

What is leucovorin, the drug the Trump administration says can cure autism?

Leucovorin is a form of folic acid, a B vitamin. Folate is essential for making DNA and other genetic material. The recommendation to use leucovorin for treating autism seems to stem from studies that show how low levels of folate in the brain can lead to a condition called cerebral folate deficiency.

“Some studies have shown that folic acid up to 2 mg per day can improve social communication but larger studies have to be done to warrant medical use,” says Prof Gulati.

What about Trump’s claim that vaccines should be graded in their use as they are linked to autism?

There have been extensive reviews and large-scale studies that have consistently demonstrated no association between autism and the MMR vaccine or vaccine components like thimerosal.

“There has been a lot of misinformation, referencing discredited research to support claims that undermine scientific consensus. The belief that vaccines might cause autism was traced back to a paper published in The Lancet in 1998, which was deeply flawed and was retracted in 2010. But it set the anti-vaccine narrative,” says Prof Gulati, who led a systematic review for AIIMS.

Her sample comprised 2,013,752 children, from varied geographic and healthcare contexts, including large national birth registries, health maintenance organisations and case–control designs. Subjects spanned North America, Europe and Asia and included both general pediatric cohorts and high-probability groups such as siblings of autistic children. “No definitive link was found,” she adds.

How much paracetamol is safe for use by adults and infants?

Depending on body weight, paracetamol use usually varies between 2 gm and 4 gms per day for adults and one should not exceed the limit. That should be spread across doses every six hours. For newborns and infants, dosage is based on weight, not age.

“The recommended limit is 10–15 mg/kg per dose, given every 6–8 hours. Do not exceed 60 mg/kg in 24 hours in newborns and infants under three months. Always use paediatric formulations (drops/syrup) and consult a doctor before dosing,” advises Dr Vivek Jain, senior director and unit head, Paediatrics, Fortis Hospital, Delhi.