Paracetamol in pregnancy: myths demystified

Paracetamol (acetaminophen), reduces fever and relieves mild to moderate pain. It is a widely available over-the-counter drug sold under various brand names, including Tylenol and Panadol. 

Because pregnant women often face limits on what medications are considered “safe,” paracetamol is typically recommended as the first-line option when something is needed.

However, over the past years, there has been increasing scientific scrutiny about whether paracetamol might carry risks to the developing fetus, particularly with longer or heavier use. Below we look at the evidence behind paracetamol usage in pregancy.

How does paracetamol work and how may it affect the fetus?

Paracetamol crosses the placenta, meaning that the fetus is exposed after a pregnant person takes it. Its mechanism of action (in adults) involves inhibition of certain pathways for producing prostaglandins, effects on oxidative stress, and possibly effects on the endocannabinoid system. These same pathways can be relevant to fetal development. There is biological plausibility for some risks, especially if exposure is high, repeated or prolonged, however biological plausibility does not mean certainty of harm.

Should I be worried?

Short-term use of paracetamol, for example, occasional or limited duration has not been clearly linked to serious adverse outcomes in many studies. Furthermore, some large cohort studies have not found associations with perinatal outcomes like preterm birth or small-for-gestational-age babies, at least for moderate, usual doses of paracetamol.

There is growing patchy or misinformation around the topic, which can cause two main problems:

1. Unnecessary anxiety for pregnant people, who may fear taking paracetamol even when needed.

2. Potential harm from untreated fever or pain, which can also affect pregnancy outcomes.

This makes clear, accurate communication essential: pregnant women should be empowered with facts, not fear.

Have risks been reported?

Several observational (epidemiological) studies suggest possible associations between prenatal paracetamol exposure and:

• Neurodevelopmental outcomes in children, including increased risks of attention‐deficit/hyperactivity disorder (ADHD), language delays, possibly autism spectrum disorder (ASD).

• Reproductive and urogenital effects, particularly in male offspring (e.g. changes in anogenital distance, cryptorchidism) in some animal experiments; human epidemiological data are less certain.

• Atopic outcomes (allergy, asthma, wheezing) in some studies.

However, many studies are observational, which means they observe associations but cannot prove causation. Confounding factors are a big concern, such as the underlying reason for taking paracetamol (fever, pain, infection) might itself have effects on the fetus, the dose, duration, and timing of paracetamol exposure vary greatly among studies, and there is inconsistency across studies; some see stronger effects, others see little or none.

Why is there all this discussion around paracetamol use in pregnancy?

Because pregnancy is such a sensitive topic, research on medicines often receives widespread media attention. Unfortunately, this can sometimes lead to oversimplified or misleading messages:

• Headlines claiming “paracetamol causes autism” or “paracetamol is unsafe in pregnancy” overstate the science. While some studies report associations, none prove causation, and the overall risk (if any) is likely to be small and influenced by many other factors.

• On social media, posts sometimes circulate that advise pregnant women to avoid paracetamol entirely, which is not what health authorities recommend. Fever itself, if left untreated, can increase risks to the fetus. Therefore avoiding all medicines could be more harmful than carefully using paracetamol.

• Mistrust of medicines can grow when partial findings are taken out of context. For example, preliminary animal studies are sometimes presented as proof of human harm, without noting the differences in biology and exposure levels.

  
  

Health agencies such as the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and Australia’s Therapeutic Goods Administration (TGA) have all stated that current evidence does not support a ban on paracetamol in pregnancy. Instead, they recommend using the lowest effective dose, for the shortest duration, and in consultation with healthcare providers.

What is currently recommended?

Paracetamol is still generally considered one of the safer options for treating fever and mild or moderate pain during pregnancy, when used according to instructions. It is commonly recommended to use the lowest effective dose, for the shortest possible duration. If you need frequent or high-dose use, consult your healthcare provider.

In summary

• The evidence to date does not support alarming headlines such as “paracetamol causes autism” in a simple cause-and-effect way.

• We can’t completely rule out any risk, especially with heavy/prolonged exposure, therefore the safest strategy is moderation.

• Based on current evidence the most appropriate usage is short-term, moderate use (following typical dose instructions) is likely relatively safe.

Pregnant women should not avoid paracetamol out of fear but should use it wisely, and always seek advice from a healthcare professional if frequent use is needed.

References

1. Bauer, A. Z., Swan, S. H., Kriebel, D., Balbus, J., Wise, L. A., & others. (2021). Paracetamol use during pregnancy — A call for precautionary action. Nature Reviews Endocrinology, 17(12), 757–766. https://doi.org/10.1038/s41574-021-00553-7

2. Brandlistuen, R. E., Ystrom, E., Nulman, I., Koren, G., Nordeng, H. (2013). Prenatal paracetamol exposure and child neurodevelopment: A sibling-controlled cohort study. International Journal of Epidemiology, 42(6), 1702–1713. https://doi.org/10.1093/ije/dyt183

3. Skovlund, E., Handal, M., Selmer, R., Brandlistuen, R., Skurtveit, S. (2017). Language competence and communication skills in 3-year-old children after prenatal exposure to acetaminophen. Paediatric and Perinatal Epidemiology, 31(1), 60–67. https://doi.org/10.1111/ppe.12326

4. Liew, Z., Ritz, B., Rebordosa, C., Lee, P.-C., Olsen, J. (2014). Acetaminophen use during pregnancy, behavioral problems, and hyperkinetic disorders. JAMA Pediatrics, 168(4), 313–320. https://doi.org/10.1001/jamapediatrics.2013.4914

5. Thompson, J. M. D., Waldie, K. E., Wall, C. R., Murphy, R., Mitchell, E. A. (2014). Associations between acetaminophen use during pregnancy and ADHD symptoms measured at ages 7 and 11 years. PLoS ONE, 9(9), e108210. https://doi.org/10.1371/journal.pone.0108210

6. Andrade, C. (2021). Paracetamol use during pregnancy and autism spectrum disorder and attention-deficit/hyperactivity disorder risk in offspring: Causation or confounding? Journal of Clinical Psychiatry, 82(5), 21f14121. https://doi.org/10.4088/JCP.21f14121

7. Streissguth, A. P., & Treit, S. (2018). The risks of paracetamol use in pregnancy: An overview of epidemiological evidence and possible biological mechanisms. International Journal of Environmental Research and Public Health, 19(4), 2128. https://doi.org/10.3390/ijerph19042128

8. TGA (Therapeutic Goods Administration, Australia). (2022). Paracetamol use in pregnancy: TGA’s safety review. https://www.tga.gov.au/news/media-releases/paracetamol-use-pregnancy

9. Marfo, N. Y., Raatikainen, K., Rautiainen, R., & others. (2022). Paracetamol use during pregnancy and perinatal outcomes: Findings from the NISAMI cohort. PLOS ONE, 17(4), e0266545. https://doi.org/10.1371/journal.pone.0266545

10. Källén, B., & Reis, M. (2015). Use of paracetamol in pregnancy and risk of adverse pregnancy outcomes. Acta Obstetricia et Gynecologica Scandinavica, 94(8), 904–911. https://doi.org/10.1111/aogs.12692

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