ACMT Position Statement: ACMT Responds to the Acetaminophen and Autism Controversy
ACMT Position Statement: ACMT Responds to the Acetaminophen and Autism Controversy
January 2, 2026
Approved November 2025
The position of the American College of Medical Toxicology (ACMT), is as follows:
Acetaminophen is the most commonly used analgesic and anti-pyretic. Approximately 60% of
women use acetaminophen during pregnancy[1]. In September of 2025, the announcement of a
reported association between autism spectrum disorder (ASD) and acetaminophen use during
pregnancy generated a storm of media attention. While numerous studies have investigated a
possible correlation between ASD and acetaminophen, the preponderance of evidence
demonstrates no such association nor a causal link. Therefore, ACMT asserts the safety of
acetaminophen in pregnancy based on the latest clinical evidence and reaffirms its support for
continued research to better understand the causes and treatment of autism spectrum
disorders.
ACMT is a professional group of medical toxicologists, including pediatricians, who specialize in
the management of adverse effects from medications in the setting of both therapeutic use and
overdose. Medical toxicologists provide care for patients of all ages, including those who are
pregnant. Our specialists have expertise in developmental toxicology and pharmacology,
including developmental pharmacology, risk assessment, and decades of experience managing
the complications of acetaminophen use and overdose. Acetaminophen is safe and effective
when taken as intended. Because of its safety profile and absence of teratogenic effects,
acetaminophen has been considered the medication of choice for fever and pain relief during
pregnancy.
Review of Evidence:
Autism Spectrum Disorder (ASD) is a pervasive neurodevelopmental disorder that is still not
fully understood. The development of ASD has been linked to a variety of environmental and
maternal causes including advanced parental age, air pollution and preterm delivery interacting
with polygenic factors[2]. Importantly, multiple studies have failed to show that autism is directly
caused by any single factor under parents’ control. In the case of acetaminophen, the best
available evidence shows no association nor causal relationship in the development of ASD.
Recent statements from government officials point to work done by Prada et al., whose paper
“Evaluation of the evidence on acetaminophen use and neurodevelopmental disorders using the
Navigation Guide methodology” asserted a link between acetaminophen use during pregnancy
and neurodevelopmental disorders[3]. This paper describes no new evidence, and while
ambitious in its attempt to review and understand existing evidence, is limited in several key
ways. First, it relies on Navigation Guide Methodology, a literature review method that depends
on the subjective interpretation of the authors to determine the strength of the evidence
presented[4]. This is in contrast to other better validated methods used to determine quality of
evidence such as GRADE. Further, the paper does not report inter-rater reliability and fails to
reach out to a diverse group of experts on their interpretation and understanding of the
literature. These steps are an essential part of reaching consensus when bringing forth new
guidelines for patient care.
Other studies reporting a small association between prenatal acetaminophen use and ASD
have suffered from several forms of potential bias and confounding factors[5–9]. These include
recall bias and confounding by indication, where the reason for using acetaminophen cannot be
separated from the use of acetaminophen. For instance, maternal fever is associated with ASD,
but also may prompt maternal acetaminophen use. Other potential confounders are maternal
factors including pain during pregnancy, maternal psychiatric illness, chronic pain, and genetic
differences resulting in increased rates of both ASD and acetaminophen use during pregnancy.
Additionally, other studies have illuminated the possibility that, when underlying genetic or
unmeasured environmental variables are taken into account, the association between maternal
acetaminophen use and ASD disappears[10–12]. In 2024, a sophisticated study of over 2
million children utilized sibling pairs and found that when these unmeasured differences were
taken into account that acetaminophen had no impact on the rates of ASD [6]. For unclear
reasons, Prada, et al. rated this sibling cohort as having the highest level of bias, despite its
robust study design and very large sample size.
Association does not prove causation, but it is a precondition for causation. If two factors are
associated, it is possible that one causes the other, that a third factor causes both, or that the
relationship is a coincidence. While an association between maternal acetaminophen use and
autism has not been convincingly demonstrated, a causal link is even less substantiated.
Medical toxicologists and other public health experts use principles introduced by Bradford-Hill
criteria as a blueprint to determine if an association is causative[13]. When applied to the
relationship between maternal acetaminophen use and ASD, more than half of these criteria are
not met, and several have fallen decidedly short or have been directly violated (See Table). As
elusive as a proven association appears to be, a causative relationship is even further away.
Table - Bradford-Hill Principles
| Bradford-Hill Principle | Definition | Present in Evaluation of APAP-Autism Link |
| Strength | Large association more likely to be causal | No, proposed association is small |
| Consistency | Multiple epidemiological studies show consistent association | No, multiple studies do not show association |
| Specificity | Exposure only causes one disease | No |
| Temporality | Exposure precedes the disease | Yes (but not in all cases) |
| Biological gradient | Dose-response relationship | No |
| Plausibility | Relationship is consistent with current body of knowledge | No |
| Coherence | Coherence between epidemiological and laboratory findings | No |
| Experiment | Experimental evidence | No, evidence is observational |
The largest studies reporting an association between acetaminophen and autism have shown a weak association [6,7,9], and the evidence is conflicting [6-9], demonstrating a lack of consistency. A dose-response relationship has not been identified and a very large study suggested negative dose-response [7]. Biological plausibility is threatened by the absence of a causative mechanism, and specificity is not shown, given the numbers of children exposed to acetaminophen without autism, and the number of autistic children who were not exposed to acetaminophen. Specificity of the effect is also lacking as acetaminophen use is postulated to cause ASD, ADHD, and other neurodevelopmental disorders.[3]
Unintended Consequences:
Pregnant patients may be discouraged from treating maternal fever, which has been linked to
significant fetal risks including neural tube defects, birth defects and is itself correlated with ASD
and other neurodevelopmental disorders[14–16]. Pregnant patients may also suffer from
untreated pain, or turn to alternative medications which have known consequences for the fetus
and the mother such as nonsteroidal antiinflammatory drugs (NSAIDS)[17] and opioid
analgesics[18], or untested dietary supplements. Mothers whose children develop ASD may
also experience unfounded guilt or receive blame from their community.
These changes also impact the medical community. Now many medical professionals may
hesitate to prescribe or counsel pregnant patients on the proper use of acetaminophen due to
fears of medicolegal consequences. Proposed acetaminophen label changes by FDA- which
bypassed their usual robust process- will contribute to this hesitation. In addition, Texas has
recently filed a lawsuit against Johnson & Johnson and Kenvue (the manufacturer of Tylenol)
stating that acetaminophen is responsible for harm against young children and unborn children.
The announcement, FDA labeling changes and the Texas lawsuit opens the door to frivolous
litigation against physicians and other healthcare providers who recommend acetaminophen to
pregnant patients and contributes to undue distress of pregnant patients.
Families affected by ASD have long been vulnerable to pseudo-scientific theories surrounding
the causes of and treatments for ASD. ASD is a broad, complex syndrome for which the medical
field has failed to produce a definite cause or treatment. From discredited links of ASD to the
MMR vaccine[19], or to the preservative thimerosal[20], publicized causes of ASD have not
been proven in rigorous well controlled studies. Such fears have resulted in vaccine hesitancy,
and subsequent outbreaks of preventable diseases and associated morbidity and mortality.
Additionally, pseudoscientific theories and fears have led to the popularity of unproven,
dangerous interventions , which medical toxicologists are often called upon to remedy. Popular
treatments without evidence supporting their effectiveness that have harmed these patients
include chelation[21], “miracle mineral solution”[22], and hyperbaric oxygen therapy[23].
Unproven treatments pose real harm and incur significant healthcare costs. Furthermore,
reliance on untested therapies may prevent families from accessing established, effective
treatments. Finally, assigning unfounded blame to acetaminophen as a cause of ASD could
truncate investigation into other more plausible etiologies of the disease.
Recommendations
Premature conclusions about the evidence linking maternal acetaminophen use and ASD are at
odds with our understanding of the current science around acetaminophen and pregnancy. We
stand in agreement with the following professional societies: American College of Obstetrics
and Gynecologists, the Society for Maternal-Fetal Medicine, the American Academy of
Pediatrics, and the Society for Developmental and Behavioral Pediatrics in asserting that we
cannot ascribe any causal relationship between acetaminophen and autism at this time.
Acetaminophen remains the preferred drug for treating fever and pain in pregnancy. ACMT
strongly encourages the scientific community and government agencies to continue to conduct
and support research for these patients, to find definitive conclusions to move beyond
speculation.
Disclaimer
While individual practices may differ, this is the position of the American College of Medical
Toxicology at the time written, after a review of the issue and pertinent literature.
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