No clear link between paracetamol use in pregnancy and autism or ADHD

By Dr. Priyom Bose, Ph.D.Reviewed by Lauren HardakerDec 3 2025

A review finds that family factors, rather than paracetamol itself, likely explain reported links to autism and ADHD, offering much-needed clarity and reassurance for pregnant women navigating conflicting health advice.

Study: Maternal paracetamol (acetaminophen) use during pregnancy and risk of autism spectrum disorder and attention deficit/hyperactivity disorder in offspring: umbrella review of systematic reviews. Image credit: Dragana Gordic/Shutterstock.com

Scientists have conducted a systematic review to evaluate whether maternal paracetamol use during pregnancy influences the risk of autism spectrum disorder and attention deficit/hyperactivity disorder (ADHD) in offspring. This review is available in the BMJ journal.

Pregnant women face confusion amid conflicting safety messages

Paracetamol, also known as acetaminophen, is a common over-the-counter medicine used to relieve moderate aches and pain and reduce fever. This medicine is also commonly used by pregnant women worldwide to relieve these symptoms. In September 2025, the US president warned against Tylenol (acetaminophen) use during pregnancy, citing potential autism risks for children exposed in utero. This announcement sparked significant anxiety among pregnant women and mothers of children with autism.

Amidst the growing uncertainties regarding paracetamol use, healthcare bodies evaluate the existing research to understand the safety of maternal paracetamol use during pregnancy. Global health agencies and expert bodies, including the European Medicines Agency, the UK’s Medicines and Healthcare Products Regulatory Agency, and the Australian Therapeutic Goods Administration, have reviewed safety concerns and confirmed that using paracetamol during pregnancy is safe.

Most systematic reviews that assessed the risk of prenatal exposure to maternal paracetamol use on the incidence of autism spectrum disorder, referred to as autism, and ADHD, showed varying methodological quality, findings, and interpretations. Several studies have not accounted for primary confounders, such as environmental factors, familial genetics, maternal health, and indications for paracetamol use, which could lead to biased findings.

Umbrella review evaluates strength of existing evidence

A recent study conducted an umbrella review of systematic reviews to investigate the overall quality and validity of existing literature to evaluate the robustness of the association between paracetamol use during pregnancy and the risks of autism and ADHD in offspring.

For systematic reviews and meta-analyses, all relevant studies were obtained from the Cochrane Database of Systematic Reviews, PsycINFO, Medline, Embase, and Epistemonikos, from inception to 30 September 2025. Two independent reviewers, JA and JS, assessed the titles and abstracts and then the full texts, and in the event of disagreement, a third reviewer (JZ) was consulted to resolve the issue. A separate pair of reviewers (MNP and HMB) assessed the methodological quality of the included systematic reviews using the AMSTAR 2 tool.

To avoid overlap among the systematic reviews considered, a citation matrix was used to map primary studies. The degree of overlap was categorized as slight (0-5 %), moderate (6-10 %), high (11-15 %), and very high (>15 %). While extracting critical information from the primary research, confounder adjustments, including maternal characteristics, familial genetic and environmental factors, and indications for paracetamol use, were considered.

Furthermore, to determine autism and ADHD outcomes in offspring, their medical records, clinician diagnoses, or completed questionnaires from parents or teachers were considered.

Many reviews show bias and overlapping evidence bases

Out of 663 citations that were obtained from a preliminary search, nine systematic reviews were considered. These reviews reported the findings from 40 primary studies, which include 37 prospective cohorts, two case-control studies, and one ecological study. It also included four meta-analyses. Of the 40 studies, six were on autism and 17 on ADHD.

All reviews were published in the last decades and were focused on the effects of paracetamol intake throughout pregnancy. One study published findings on both antenatal and postnatal use. Interestingly, a few studies used unsuitable research designs to establish the exposure-outcome association.

Only one review comprising two studies, conducted in Sweden and Norway, had adjusted for shared familial factors and unmeasured confounding. These studies had also estimated the effect of dose and duration of paracetamol use on neurological development. Importantly, in these sibling-controlled analyses, the small positive associations observed in general cohort studies were substantially reduced or disappeared, suggesting that shared familial factors, not paracetamol itself, may explain much of the observed risk.

The current review identified significant methodological weaknesses in several key areas. Most reviews did not use a comprehensive literature search, lacked a registered protocol, and did not provide a list of excluded studies with reasons for exclusion. Assessment of risk of bias in primary studies was often missing or only partially addressed.

None of the systematic reviews used the recommended tool to evaluate bias in non-randomised trials. Most studies did not consistently apply appropriate statistical methods or adjusted estimates in their meta-analyses.

Only one review in the meta-analysis adjusted for confounding effects. Just three systematic reviews considered how the risk of bias affected their results. Similarly, only one review properly examined publication bias during quantitative synthesis. Considering these issues, the overall confidence in the results was rated as low or critically low (seven reviews were critically low and two were low) in systematic reviews. The corrected covered area was just 23 %, revealing significant overlap among the nine reviews, which were mostly based on the same primary studies.

Research suggests that avoiding paracetamol for high fever may increase pregnancy risks. A consistent positive association was observed across all reviews between maternal paracetamol use during pregnancy and adverse neurodevelopmental outcomes in children. Despite this, seven out of nine reviews advised caution, warning that the current evidence does not establish a causal relationship with autism or ADHD due to limited data, biases in original studies, and uncontrolled confounding factors.

Meta-analyses reported small increased risks for ADHD and autism, especially with higher or prolonged use and third-trimester exposure. However, confounding factors and shared familial influences were not adequately addressed. The umbrella review emphasized that the strongest available evidence, sibling-controlled studies, does not show a clear association once shared familial factors are accounted for.

The authors also note that there is no well-established biological mechanism or consistent animal evidence supporting a causal link at therapeutic doses, further weakening the argument for harm.

Guidance supports continued paracetamol use when clinically necessary

Although some reviews have found an association between maternal paracetamol use in pregnancy and autism or ADHD in children, the current evidence is weak and insufficient to confirm a causal relationship.

Future research should employ stronger study designs that better control for confounding factors to determine the actual risks of paracetamol exposure during different stages of pregnancy and its impact on child neurodevelopment.

Given the lack of convincing evidence of harm, and the known risks of untreated fever and pain, the authors reiterate current clinical guidance: pregnant women should continue to use paracetamol when needed, at the lowest effective dose for the shortest duration.

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