The Implications of Acetaminophen Use During Pregnancy: A Critical Examination of Public Health Policy

Understanding the Potential Risks of Acetaminophen

The recent news regarding the possible association between the use of Tylenol, the brand name for acetaminophen, and comparable products by pregnant women, with an increased risk of autism and Attention Deficit Hyperactivity Disorder (ADHD) in children, has sparked a significant amount of discourse. This conversation was met with an avalanche of rebuttals and knee-jerk fact-checking from various media outlets. The dialogue, which should have been a serious national discourse on public health risks posed by widely marketed and consumed drugs and food products, devolved into a political theater. The usual cast of television and media reporters almost entirely refuted any associative evidence, even if such evidence existed, without considering the basic scientific data and the weight-of-evidence-based approach utilized by Health and Human Services in making such determinations.

Even a highly respected journal such as Nature sensationalized the FDA policy with a title, “Trump links autism and Tylenol.” Ironically, the same Nature article indicates that the reported association between paracetamol use by pregnant women and autism is exceedingly small, clearly implying that such a link could not be entirely ruled out. Would a pregnant woman accept even a “small risk,” however minimal it might be, when informed of the potential, low-level risk of autism in her expectant child as an acceptable risk?

The Evidence Surrounding Acetaminophen Use

The study did not unequivocally conclude that there is no association whatsoever between the use of Tylenol during pregnancy and autism. The Nature report accurately states that paracetamol, the active analgesic ingredient in Tylenol, has a long history of use by pregnant women with an established safety record. However, very few alternatives to paracetamol exist that are both safe and effective as painkillers for use by pregnant women. Nevertheless, is it prudent from a public health policy standpoint to accept the small potential risk of Tylenol use-associated autism? Is such a public health policy considered sound if it overrides a low-level risk and does not include a label claim that such a risk may exist?

The Harvard School of Public Health published a report in the summer of 2025 on the plausible link between fetuses exposed to acetaminophen—also known by the brand name Tylenol or as paracetamol—by expectant mothers during pregnancy, which may more likely result in neurodevelopmental disorders (NDDs), including autism and ADHD. This conclusion is drawn from a new study published by the dean of the faculty at the Harvard School of Public Health.

The reported study is a summary analysis of 46 previous research investigations worldwide on the potential link between acetaminophen use by pregnant women and pediatric neurodevelopmental disabilities (NDD) in children. A rigorous and comprehensive meta-analysis of published research literature using the Navigation Guide Systematic Review—the most widely accepted analytical framework for the analysis of multiple research publications—indicated an association between acetaminophen (Tylenol) exposure during pregnancy and an increased incidence of NDD.

An earlier prospective cohort study involving 1,011 women who reported taking Tylenol during pregnancy revealed that children exposed to the painkiller in utero scored significantly higher on three of the seven Child Behavior Checklist (CBCL) syndrome scales, reporting withdrawal, sleep problems, and attention deficiency. All scores reported were significantly associated with prenatal stress, with two scores on sleep and attention problems significantly higher among children with maternal exposure to Tylenol during pregnancy.

The Mechanisms Behind Behavioral Disorders

There are other studies as well on prenatal stress and behavioral disorders resulting from pregnant women's use of acetaminophen during pregnancy, which has been shown to lead to behavioral problems among children. Researchers interpret the mechanism of action as the outcome of immune system dysfunction and increased action in the hypothalamic-pituitary-adrenal axis. According to this mechanism of action, pregnant women experiencing stress, such as pain, result in the overactivation of the axis, which, in prolonged or severe cases, could lead to increased cortisol levels and exposure to the fetus. While extreme stress during pregnancy is not widespread, it is not uncommon either, necessitating the use of painkillers or other similar medical countermeasures.

The U.S. Food and Drug Administration initiated the process for a label change for acetaminophen (Tylenol and comparable products) to reflect evidence suggesting that the use of acetaminophen by pregnant women may be associated with an increased risk of neurological conditions such as autism and ADHD in children.

An activist section of the science policy influencers ruled out any associative relationship, rejecting the FDA's notice to modify the label on acetaminophen containers to include a safety note. They argued that such a change would be highly dangerous. The FDA did not ban the use of acetaminophen during pregnancy or impose any restrictions on its use. The new measure requires a notation on the label of the container that such a risk may exist, leaving the decision to take the medicine in the hands of the consumer. Since acetaminophen is an over-the-counter medication requiring no prescription, the informed decision to use the painkiller is appropriately left to the consumer.

The Debate Over Labeling and Public Perception

The counterfactual argument that even a precautionary note on the label may increase “fear in pregnant women at a time when they truly don’t need to” is not supported by published scientific evidence. This interpretation has been widely circulated, yet it lacks a solid foundation in scientific rigor.

I would like to draw a parallel from the Environmental Protection Agency (EPA) under the Superfund program, which aims to reduce or eliminate the risk of cancer and other diseases posed by toxic chemicals from hazardous dump sites. Using a cancer risk extrapolation model, an excess potential cancer risk of one in a million people living close to the dump site and exposed to the cancer-causing chemical serves as the cut-off level. Any projected risk exceeding one in a million cancer incidents necessitates remediation of the site and its restoration to acceptable risk levels.

Now, let us compare this to another policy-setting approach utilized by the U.S. Environmental Protection Agency to assess the threat of exposure to hazardous chemicals from Superfund landfill sites. By employing a hypothetical exposure and statistical extrapolation of cancer incidence, the science-based policy establishes a safe and acceptable level of risk at anything exceeding one in a million cancers. This is irrespective of whether cancer incidence has increased in the community living close to a dump site. EPA policymakers consider an excess of one case in a million as sufficiently protective, without any causal or associative evidence to substantiate it. Hazardous chemicals from a dump site pose serious risks, including the risk of developing cancer. The comparison is merely based on the science-based policy-setting rationale and approach.

Autism Prevalence and Public Health Policy

Let us examine autism. According to the U.S. Health and Human Services, the prevalence of autism has increased in the U.S. to 1 in 31 children and 1 in 45 adults with Autism Spectrum Disorder (ASD). Approximately 1 in 44 children in the U.S. is diagnosed with an autism spectrum disorder annually. Of these 44 children diagnosed, approximately 1 in 27 boys is identified with autism, while 1 in 116 girls is identified with autism (Autism Speaks, 2022). Over the next decade, an estimated 707,000 to 1,116,000 teens (70,700 to 111,600 each year) will enter adulthood and age out of school-based autism services.

Let us pause for a moment. A hypothetical cancer risk based on hypothetical exposure to hazardous chemicals from a waste site resulting in an estimated excess cancer incidence of one in a million is the governing policy of the EPA. Any risk exceeding this estimate requires site remediation and restoration. The one in a million excess lifetime cancer risk, primarily based on hypothetical exposure and risk scenarios for cancer from toxic chemicals from a Superfund site, is deemed the acceptable level, and anything above necessitates remediation. In contrast, a small but notable association of paracetamol (Tylenol) linked to autism—now with an increasing prevalence of cases in the U.S. population—raises questions about the soundness of public health policy under the same premise of science-based policy setting.

Given that there is a notable body of evidence linking the use of acetaminophen during pregnancy to autism in newborn children, and considering the notable surge in the prevalence of autism in recent years—approximately 1 in 31 children exhibiting some form of autism and related developmental disabilities—a public health policy that is protective of children, such as a label change, is a prudent measure. This approach leaves the ultimate decision to take the medicine in the hands of the patient-consumers.

Conclusion: The Need for Rigorous Scientific Discourse

National discourse on topics relating to public health has been greatly aggravated since the COVID-19 pandemic, during which non-scientific biases distorted key facts regarding the pandemic and the necessary public health response. It is imperative that scientific analysis and reporting remain rigorously guarded against external influences, as any compromise to the integrity of this analysis will undermine the very foundation of science-based policymaking frameworks.

The discourse surrounding acetaminophen use during pregnancy and its potential implications for autism and ADHD in children is not merely an academic exercise; it is a matter of public health that requires careful consideration, rigorous scientific inquiry, and a commitment to transparency in communication. The stakes are high, and the need for clarity and precision in our discussions has never been more critical.