Study Links Paracetamol Exposure in Pregnancy to Child Development

Overview of Research Findings

Recent research from Scandinavian scientists has found that children who were exposed to acetaminophen, also known as paracetamol, during pregnancy did not exhibit higher rates of autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), or intellectual disabilities compared to their peers. Published in JAMA earlier this year, the study monitored over two million children born in Sweden from 1995 to 2019. The researchers concluded that there is no causal relationship between this common over-the-counter pain reliever and the aforementioned conditions. Notably, paracetamol is the active ingredient in well-known brands such as Tylenol and Panadol, as well as in cold and flu medications like LemSip and DayQuil.

Further Investigations

An update on this subject from September 22, 2025, reveals that researchers from New York University expanded upon the previous findings. They analyzed medical records of over one million Danish children born between 1998 and 2015, utilizing sibling discordance analysis to determine whether maternal health during pregnancy influenced the likelihood of developing autism. Their investigation revealed that genetics played a significant role, indicating that inherited factors from parents are more determinative of a child’s neurodevelopment than environmental influences.

Previous Concerns and Research

Initial Warnings

Prior studies had suggested a potential connection between paracetamol use during pregnancy and the risk of neurodevelopmental disorders. However, the Swedish researchers argued that it is not the medication itself interfering with brain development, but rather the underlying health conditions of the mothers necessitating the use of paracetamol that may be more influential.

FDA Alert

In 2015, the U.S. Food and Drug Administration issued a drug safety notice regarding potential risks associated with prenatal paracetamol exposure, following growing concerns from the medical community. More than 25 research studies across various regions have since examined the potential adverse effects of paracetamol on neurodevelopment.

A Comprehensive National Study

Research Methodology

The investigators from the Karolinska Institute conducted an extensive review of over 2.4 million medical records spanning 25 years. This comprehensive analysis allowed them to identify 185,909 children exposed to paracetamol in utero, enabling more nuanced comparisons than previous studies. The researchers specifically designed this study to investigate potential links between paracetamol and conditions such as ASD, ADHD, and intellectual disabilities.

Findings on Risk Factors

Initially, a slight increase in diagnoses of neurodevelopmental disorders—specifically a 0.09% increase over ten years—was noted among children whose mothers used paracetamol. However, once other factors such as premature birth and maternal health were considered, this increased risk was no longer significant.

Genetic Considerations

Role of Genetics

The researchers theorized that any perceived association between paracetamol and neurodevelopmental disorders may stem from maternal health conditions or genetic predispositions. They analyzed sibling pairs to determine if those exposed to paracetamol during pregnancy were more likely to develop disorders compared to their siblings who were not exposed. The results indicated no significant differences in the likelihood of developing such disorders among siblings, suggesting that genetics and maternal health are pivotal factors.

Environmental Influences

The study also highlighted that socio-economic status and maternal health are major risk factors for the development of ASD, ADHD, or intellectual disabilities. Recent data collected during the COVID-19 pandemic showed that maternal fever could impact fetal brain development, regardless of medication used.

Conclusions and Implications

Reassurance for Expecting Parents

Expectant parents concerned about the effects of acetaminophen/paracetamol on brain development can take comfort in the study’s findings, as there is little evidence to support a causal link with ADHD, ASD, or intellectual disabilities. The research underscores the importance of maternal health as a key factor in child development outcomes, emphasizing the need for accessible healthcare and social support for pregnant individuals.

References

1. Ahlqvist VH, Sjöqvist H, Dalman C, et al. Acetaminophen Use During Pregnancy and Children’s Risk of Autism, ADHD, and Intellectual Disability. JAMA. 2024;331(14):1205-1214. doi:10.1001/jama.2024.3172
2. Leppert B, Havdahl A, Riglin L, et al. Association of Maternal Neurodevelopmental Risk Alleles With Early-Life Exposures. JAMA Psychiatry. 2019;76(8):834-842. doi:10.1001/jamapsychiatry.2019.0774
3. Drug Safety Communication. Jan 9th 2015. FDA has reviewed possible risks of pain medicine use during pregnancy.
4. Bauer AZ, Swan SH, Kriebel D, et al. Paracetamol use during pregnancy — a call for precautionary action. Nat Rev Endocrinol. 2021;17(12):757-766. doi:10.1038/s41574-021-00553-7
5. Croen LA, Qian Y, Ashwood P, et al. Infection and Fever in Pregnancy and Autism Spectrum Disorders: Findings from the Study to Explore Early Development. Autism Res. 2019;12(10):1551-1561. doi:10.1002/aur.2175
6. Dreier JW, Andersen AMN, Berg-Beckhoff G. Systematic Review and Meta-analyses: Fever in Pregnancy and Health Impacts in the Offspring. Pediatrics. 2014;133(3):e674-e688. doi:10.1542/peds.2013-3205