Acetaminophen, also called Tylenol or Paracetamol, can be described as the best OTC analgesic to use throughout pregnancy when there is discomfort or fever. It is safe and the most widely used pregnancy remedy by more than half of the pregnant women across the globe. However, this is an assumption that is questioned by the emergent research. A 2025 review in Environmental Health applies high levels of scientific scrutiny to consider relations between prenatal exposure to acetaminophen and neurodevelopmental disorders (NDDs) e.g. autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in children via the Navigation Guide methodology.
Both headed by Diddier Prada of Columbia University, the team combed the PubMed database through February 25, 2025. They examined 46 high quality articles, and rated them as far as their bias and quality of the evidence were concerned. This has been serious scientific methodology (adapted to environmental health assessment), in the sense that it is objective and does not use cherry-picked information. Findings? On a pattern indicating that acetaminophen is not as harmless as considered.
Running the Evidence
Among the 46 studies, 27 were positive associations: the children of women using acetaminophen during pregnancy had an increased NDD prevalence. Nine reported that there was no association (null), and four indicated a protectiveness (negative). Studies of higher quality were more likely to find positive relationships which further supports making this claim.
Key highlights:
The matter of dosage and time: Frequent or prolonged use of Doxycycline, specifically during the second/third trimesters, were been associated with risks. In one study 29+ days exposure showed a 20-30 percent increase in ADHD/ASD.
Biological Plausibility: Acetaminophen enters the placenta area, which can cause a disturbance in fetal brain development in terms of showing effects on hormones, inflammation, or oxidative stress. This is evidenced by the use of animal models, reporting changes in behavior of the offspring.
Consistency Across Studies: Cohorts in the US, Europe, and Asia mirrored results. The odds ratios were 1.19-1.45 and 1.13-1.34, respectively, of ASD and ADHD.
The Confounding Factors: The results have been adjusted to maternal health, smoking and genetics, but the correlation still existed.
The review classified evidence as sufficient as an association, which means that there was more evidence of positive results than null/negative findings. But it is not known to be toxic more research to determine causality.
This is Cause of Alarm to Expectant Mothers
DDs impact 1 in 6 children worldwide without being able to relieve the burden on themselves and the respective societies. This is because, although acetaminophen may have a minor role, it may affect millions of people. The prevalence of the drug increases fears even more: People simply use it to get rid of a headache, back pain, or fever without any other option.
Drawing on limitations: Most studies depend on self reported use, which creates a problem of possible recall bias. Few quantified blood levels directly. Determining causality is complicated by confounders such as underlying diseases (why an acetaminophen?) Are you ready to take it? However, the review is powerful in providing disclosure of all the biases and the downgrading of the evidence.
Experts want to alert, not to panic. The American College of Obstetricians and Gynecologists continue to judge acetaminophen to be safe in small doses but recommends that its use be limited. Alternatives? Other pain relievers can include things like rest, fluids, or physical therapy when the pain is mild in nature.
Practical Implications to Public Health and Future Research
This is not an unprecedented alarm they had previously been predictions in meta analyses, but the Navigation Guide brings credence, similar to the EPA toxin ratings. Calls upon:
Improved research: Prospective trials that have biomarkers (such as cord blood acetaminophen levels) and genetic information.
Changes in Policy: Warnings in FDA/EMA labels? Greater provider education.
Harmless alternatives: Find non acetaminophen pain medications that are pregnancy safe.
To society, it highlights the role of environmental health in shaping up the brain. Toxins such as lead or air pollution are already connected to NDDs and now acetaminophen increases the puzzle.
Practical Recommendation: What pregnant Women can do
If pregnant or planning:
Ask your doctor before any medications discuss risks / benefits
Use in Track: Shortest effective dose only.
Find substitutes: Acupuncture, yoga, or compresses to relieve the pain.
Monitor fevers: untreated high fevers are also known to harm fetuses finding the balance.
For everyone: Support research funding for maternal-fetal health. Awareness empowers choices.
This review doesn’t prove causation but builds a compelling case for reevaluation. As Prada notes, “Sufficient evidence warrants action.” Stay informed your choices matter.
Conclusion: The Precautionary and the Loud.
The complexities of medication safety are also brought out by prenatal acetaminophen potential NDD links. Although not conclusive, the evidence calls into question caution. Future research can help to decipher but, in the meanwhile, it is safe that not much be used. Knowledge secures the coming generations
References & Resources
Prada D, Ritz B, Bauer AZ, Baccarelli AA. Evaluation of the evidence on acetaminophen use and neurodevelopmental disorders using the Navigation Guide methodology. Environmental Health. 2025;24:56. doi:10.1186/s12940-025-01208-0
American College of Obstetricians and Gynecologists. Acetaminophen use during pregnancy. [ACOG Statement, 2023].
Liew Z, Ritz B, et al. Prenatal acetaminophen use and child attention and executive function. Epidemiology. 2016.