A new study states: acetaminophen in pregnancy is safe and does not cause autism

The researchers examined 43 previous studies that dealt with the possible connection between paracetamol use during pregnancy and autism, ADHD and intellectual disability. These are hundreds of thousands of children who were included in the various analyses, a figure that makes the review one of the most comprehensive ever done in the field.

According to the data, no significant relationship was found between exposure to acetaminophen in utero and a diagnosis of autism, attention deficit disorder or intellectual disability. Some of the included studies even compared siblings born to the same mother, with one exposed to paracetamol during pregnancy and the other not, and there too no difference in neurodevelopmental outcomes was found. The researchers emphasize that this is the most rigorous analysis to date, one that manages to neutralize many intervening factors.

The researchers specifically refer to the claims heard in the political arena in the United States, even if they do not mention Trump by name. They state that claims that acetaminophen causes autism are not evidence-based. According to them, family and genetic factors, including the fact that autism tends to run in families, are a much more likely explanation for the links found in past observational studies, rather than a direct effect of the drug itself.

Meanwhile, the researchers raise another important point. Paracetamol is usually taken for short periods of time, and when it comes to longer use, it is possible that the medical condition for which the woman is taking the drug, such as chronic inflammation or a persistent infection, is the one that affects the development of the fetus’s brain, and not the drug itself. This is a fundamental difference between cause and effect, a difference that early studies were not always able to clarify.

The uproar over the issue erupted after a White House press conference in September, in which Trump said that taking Tylenol during pregnancy was “not good” and urged pregnant women to avoid the drug. The statements provoked sharp criticism from medical, women’s health and scientific organizations around the world, who warned against the spread of incorrect information that could lead women to avoid essential treatment. Health organizations and government officials around the world called on the public to ignore the claims and emphasized that the medical guidelines have not changed.

At the time, Canview, the manufacturer of Tylenol, published an official statement saying: “Acetaminophen is the safest pain reliever for pregnant women throughout pregnancy, when it is used as needed. Without the drug, women are forced to choose between suffering from medical conditions such as fever that may harm them and the fetus, and using other drugs that are dangerous during pregnancy.” The company added that “more than a decade of rigorous research, approved by leading medical professionals and regulators in the world, found that there is no reliable evidence of a link between acetaminophen and autism.”