Tylenol is displayed at a convenience store in downtown Seoul 2025.9.23 / News1

Controversy is brewing over claims that acetaminophen, the active ingredient in Tylenol commonly used by pregnant women for pain and fever relief, may increase the risk of autism. However, regulatory agencies and academic institutions continue to assert that there is currently insufficient evidence to establish a causal relationship.

According to pharmaceutical industry sources on Thursday, U.S. President Donald Trump publicly stated that taking Tylenol during pregnancy increases the risk of autism. This statement has garnered significant attention from relevant agencies and researchers worldwide, sparking a global debate.

The U.S. Food and Drug Administration (FDA) promptly issued a statement acknowledging that some studies have suggested a possible link, but emphasized that there is no evidence to prove a causal relationship. While the FDA has initiated procedures to strengthen the product’s warning labels, they stressed that it is not yet time to alter usage guidelines.

The World Health Organization (WHO) also stated that the evidence is inconsistent and insufficient to establish a causal relationship. The European Medicines Agency (EMA) similarly declared that there is no basis to change current recommendations, reiterating its principle regarding acetaminophen use during pregnancy: the minimum effective dose for the shortest possible duration.

In South Korea, the Ministry of Food and Drug Safety announced that it is reviewing international research and academic trends. The Korean Pharmaceutical Association also noted that scientific evidence remains insufficient.

Tylenol is displayed at pharmacies in Seoul 2025.9.24 / News1

No Definitive Evidence... Fever in Pregnant Women May Pose Greater Risk to Fetus

The controversy largely stems from observational studies that have reported higher rates of autism and attention-deficit/hyperactivity disorder (ADHD) among children whose mothers took acetaminophen during pregnancy.

However, observational studies only demonstrate correlations, not causation. A large-scale cohort study in Sweden initially showed risk signals in general analyses, but these differences disappeared when comparing siblings, suggesting that genetic factors or home environments may have influenced the results.

A recently published review paper, which synthesized dozens of studies, concluded that while results suggesting a correlation exist, causation remains uncertain. Researchers from Mount Sinai in the U.S. reported similar findings.

Pregnant women face practical constraints: fever increases the risk of preterm birth and birth defects, while pain imposes a burden on both mother and fetus. Alternative medications like ibuprofen, which is often suggested, can pose risks to fetal kidneys in late pregnancy, thereby limiting their use.

Acetaminophen has been the most widely used medication for pregnant women for decades, and international guidelines maintain the principle of using the minimum necessary dose for the shortest possible duration when needed.

The Korean Pharmaceutical Association emphasized that fever itself may have a greater negative impact on the fetus than the medication. They maintain that using an appropriate dose of acetaminophen under medical supervision remains the safest option. Both the FDA and WHO have reiterated that there is no definitive evidence to establish a causal link between acetaminophen use and autism.

Controversy is brewing over claims that acetaminophen, the active ingredient in Tylenol co …

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