Research Finds No Clinically Important Increase in Autism, ADHD Following Prenatal Paracetamol Use

A new systematic review and meta-analysis published in The Lancet Obstetrics, Gynaecology, & Women’s Health determined that current evidence does not indicate a clinically important increase in the likelihood of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in offspring when paracetamol—or acetaminophen (Tylenol; Kenvue) in the US—is used as directed among pregnant individuals.¹

FDA Label Update Reflects Supposed Effects of Acetaminophen’s Prenatal Use

This review follows the FDA’s announcement in September 2025 that the label for acetaminophen would be changed to reflect supposed evidence that use by pregnant women may be associated with a heightened risk of neurological conditions, such as ASD and ADHD, in offspring.²

Along with this announcement, the agency also noted that while studies describe an association between acetaminophen and neurological conditions, a causal relationship has not been established. They cautioned that acetaminophen is the only OTC drug approved to treat fevers during pregnancy, which can be very dangerous for the fetus. Ibuprofen and aspirin are generally not recommended until after 20 weeks’ gestation. Overheating—or hyperthermia—during pregnancy, especially for a long duration and during the first trimester, may increase the risk of harm to the fetus.²

Following this announcement, medical societies, including the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine, criticized the actions and called them “highly concerning to clinicians” and “irresponsible when considering the harmful and confusing message they send to pregnant patients.”²

What Did the Systematic Review and Meta-Analysis Find?

Amid concerns of paracetamol and acetaminophen use and its potential associations with neurodevelopmental conditions, the investigators of this new paper searched MEDLINE, Embase, ClinicalTrials.gov, and the Cochrane Library from their inceptions to September 30, 2025—which is shortly after the FDA’s announcement initiating a label change—that reported adjusted estimates of the risk of ASD, ADHD, and intellectual disability. Studies were considered if they utilized validated questionnaires or medical records to define outcomes, reported maternal comorbidities and treatments, and compared pregnancies with and without paracetamol exposure. Unadjusted studies were excluded.¹

The primary outcomes were the associations between prenatal paracetamol exposure and the likelihood of ASD, ADHD, and intellectual disability. Analyses were restricted to sibling-comparison studies with adjusted estimates, and odds ratios (OR) were calculated. Additionally, random-effects meta-analyses used the generic inverse variance method, and subgroup analyses were performed when possible (trimester, duration of use, offspring sex, and follow-up length).¹

A total of 43 studies were included in the systematic review, and 17 studies were included in the meta-analysis. When considering sibling comparison studies, the investigators observed that paracetamol exposure during pregnancy was not associated with the risk of ASD (OR, 0.98 [95% CI 0.93–1.03]; p = .45), ADHD (OR, 0.95 [95% CI 0.86–1.05]; p = .31), or intellectual disability (OR, 0.93 [95% CI 0.69–1.24]; p = .63). Notably, there was also no association between paracetamol intake during pregnancy and these outcomes (ASD: OR, 1.03 [95% CI 0.86–1.23], p = .78; ADHD: OR, 0.97 [95% CI 0.89–1.05], p = .49; intellectual disability: OR, 1.11 [95% CI 0.92–1.34], p = .28) when considering only studies at low risk of bias according to the Quality In Prognosis Studies tool. This absence of association persisted even when considering all studies with adjusted estimates and those with more than 5 years of follow-up.¹

These findings follow and support a November 2025 comprehensive review of 40 studies and 9 systematic reviews, which also found no link between maternal acetaminophen use and ASD or ADHD.³ Both these findings and the recent paper contradict the studies cited by the FDA and the US Department of Health and Human Services, all of which have methodological pitfalls, such as smaller sample sizes, self-reported data, and lack of control for confounding factors, suggesting unreliability.^1,3

“Paracetamol is typically used only intermittently, and its prolonged use raises questions about whether the underlying health condition prompting extended use might be more important in shaping neurodevelopmental outcomes rather than the drug itself,” the authors explained. “Maternal use of paracetamol during pregnancy does not seem to increase the likelihood of ASD, ADHD, or intellectual disability. This finding supports the recommendations made by major medical organizations regarding its use.”¹

REFERENCES

1. D'Antonio F, Flacco ME, Valle LD, et al. Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis. Lancet Obstet Gynaecol Women's Health. 2026. doi:10.1016/S3050-5038(25)00211-0

2. Halpern L. FDA Alleges Association Between Prenatal Acetaminophen Use and Autism in Children. Pharmacy Times. September 23, 2025. January 19, 2026. https://www.pharmacytimes.com/view/fda-alleges-association-between-prenatal-acetaminophen-use-and-autism-in-children

3. Gerlach A. Major Review Finds No Link Between Maternal Tylenol and Autism Spectrum Disorder, ADHD. Pharmacy Times. November 10, 2025. Accessed January 19, 2026. https://www.pharmacytimes.com/view/major-review-finds-no-link-between-maternal-tylenol-and-autism-spectrum-disorder-adhd