Debunking Trump’s Tylenol-autism link: What science says about pregnancy use of paracetamol

US President Donald Trump on Monday triggered a row when he linked pain reliever Tylenol or paracetamol to autism when he urged pregnant women to “limit its use unless medically necessary”. By doing so, Trump has fueled conspiracy theories that claim paracetamol, the main ingredient in Tylenol, also known in the US as acetaminophen, causes autism, though studies have not settled a connection between autism and Tylenol.

Following Trump’s statement, the US Food and Drug Administration (FDA) also announced that it would issue a warning label on the drug, citing a “possible association” between autism in children and the use of acetaminophen.

What is Tylenol ?

Considered one of the safest over-the-counter options for pain or fever in pregnant women, Tylenol is used by most women without side effects. Without the drug, women face a dangerous choice between suffering through conditions like fever, which could harm the baby, too. Other common pain relief options, like ibuprofen or regular-dose aspirin have serious side effects during pregnancy.

What experts say

The maker of Tylenol in the US, Kenvue, was the first to issue a statement against Trump’s claims. A statement issued by the drug company said, “independent, sound science clearly shows that taking acetaminophen does not cause autism.”

Medical experts were baffled at Trump’s statement, with many tagging it irresponsible. According to New York University bioethicist Art Caplan, Trump’s statement was “the saddest display of a lack of evidence, rumors, recycling old myths, lousy advice, outright lies, and dangerous advice I have ever witnessed by anyone in authority.”

Many scientists believe the research so far does not have anything substantial to link autism and acetaminophen or paracetamol in pregnancy.

Scientists say that the most robust research does not link autism and acetaminophen use in pregnancy. “The better controlled studies are less likely to find even a small risk,”  Helen Tager-Flusberg, a psychologist who studies autism at Boston University, Massachusetts, told Nature. “And even then, what we’re talking about is a minor association. … We do not think that taking acetaminophen is in any way contributing to actually causing autism.”

One study carried out in this regard was held in Sweden between 1995 and 2019 by Viktor Ahlqvist, an epidemiologist at the Karolinska Institute in Stockholm, and co-author of what might be the biggest study1 on the link. He gathered data on nearly 2.5 million children born in Sweden between 1995 and 2019. He accessed data from the country’s  extensive health records — data on acetaminophen prescriptions during pregnancy and on self-reported use collected by midwives.

The study showed that around 1.42% of children exposed to acetaminophen during pregnancy were autistic, compared to 1.33% of children who were not exposed. This was a “very small” difference, according to Ahlqvist.

Ahlqvist’s team also compared pairs of siblings (born to the same mother), one of whom had been exposed to acetaminophen and one who had not, hoping to find any detected difference due to the drug.  However, no association was found between acetaminophen and autism.

The American College of Obstetricians and Gynecologists also rubbished Trump’s claims, adding that suggestions that Tylenol use in pregnancy causes autism are “irresponsible when considering the harmful and confusing message they send to pregnant patients.”

"There is no robust evidence or convincing studies to suggest there is any causal relationship," Monique Botha, a professor in social and developmental psychology at Durham University, told the BBC. She reiterated that Tylenol continues to be the only safe option for pregnant women.