A recent study, the largest of its kind, found no evidence to suggest that using acetaminophen during pregnancy increases the risk of autism, ADHD, or intellectual disability in children. The study gathered data from over 2.4 million children born in Sweden, including siblings who were not exposed to the drug before birth.A study published in the Journal of the American Medical Association (JAMA) conducted by researchers at Drexel’s Dornsife School of Public Health and Karolinska Institutet of Sweden examined a cohort of more than 2.4 million children born in Sweden, including siblings who were not exposed to the drug before birth. The study followed the children for up to 26 years after birth. Acetaminophen, a generic drug found in Tylenol and other medications like Theraflu, Excedrin, and Mucinex, is commonly used as a pain reliever and fever reducer.In the study, there was a slight increase in the risk of autism, ADHD, and intellectual disability in the general population, which aligns with previous studies. However, there was no increased risk of these conditions when comparing full siblings. This is significant because siblings share a similar genetic background and are exposed to many of the same environmental factors during development. By comparing siblings, the study was able to control for these shared factors, which are difficult to measure in other ways.Epidemiological studies show that users of acetaminophen have different characteristics compared to non-users, and standard statistical analyses may not be able to account for all these differences. Co-senior author Brian Lee, PhD, stated that sibling comparisons can help control for familial factors that could impact the relationship between acetaminophen use during pregnancy and the risk of neurodevelopmental conditions. The data used in the study was gathered from Swedish sources.Researchers used data from Denmark’s national health and prescription drug registers to examine medication use during pregnancy from 1995 to 2019. Only 7.5% of the study sample, which included 185,909 children, were exposed to acetaminophen while in utero. Previous studies showed that acetaminophen use during pregnancy varied widely, ranging from 6.2% in Denmark to 10 times higher in the U.S. Other research suggested that pregnant individuals who could benefit from acetaminophen might avoid taking it due to concerns about potential side effects. For example, a 2019 study of 850 pregnant Swedish individuals found this to be the case.ns, where over 60% of people thought that taking medication during the early stages of pregnancy could be “probably harmful” or “harmful.”
Co-senior author Renee M. Gardner, PhD, from Sweden’s Karolinska Institutet, stated, “This study’s findings may bring some relief to pregnant individuals who use acetaminophen for pain or fever management, as there are limited safe alternatives for relief available. We hope that our results offer comfort to expectant parents when they have to decide whether to take these medications during pregnancy while dealing with pain or fever.”
The authors recommend that all patients should adhere to the guidelines for medication use during pregnancy.are ongoing to better understand the potential risks of using acetaminophen during pregnancy. The agency stated that it is important for pregnant women to consult with their healthcare provider for guidance on the safety of using acetaminophen. The study authors emphasized the need for further research to identify the specific factors that may contribute to the increased risk of neurodevelopmental disorders in children exposed to acetaminophen in utero. They pointed out that genetics may play a role in this association and called for additional studies to explore this mechanism. In 2015, the U.S. Food and Drug Administration mentioned that research is ongoing to gain a better understanding of the potential risks of using acetaminophen while pregnant. The agency emphasized the importance of pregnant women seeking advice from their healthcare provider regarding the safety of using acetaminophen.The scope of research on over-the-counter pain medicines is too narrow to provide specific recommendations, but it is important to note that unmanaged and persistent pain during pregnancy can lead to adverse effects such as depression, anxiety, and high blood pressure in the mother. A 2021 consensus statement published in Nature Reviews Endocrinology by a global team of researchers and medical professionals advised that pregnant individuals should minimize their exposure to acetaminophen by using the lowest effective dose for the shortest duration possible. This recommendation is based on studies indicating that prenatal exposure to the drug may elevate the risk of neurodevelopmental and other disorders.Although the study conducted by Drexel and Karolinska used data on prescribed acetaminophen and reports from pregnant individuals to their midwives during prenatal care, it may not account for all over-the-counter use in all patients. However, the findings are based on data from a large representative sample and control various other factors that may be associated with neurodevelopmental disorders.
This research was funded by the National Institute of Neurological Disorders and Stroke 1R01NS107607, with no involvement from the National Institutes of Health in conducting the study or interpreting the results. Lee has received consulting fees for literature reviews beyond the funding.for legal firms but has not provided any expert litigation, and no third parties were involved in the research.
In addition to Gardner and Lee, other authors of the paper include shared lead authors Viktor H. Ahlqvist, PhD, and Hugo Sjöqvist, Christina Dalman, MD, PhD, Håkan Karlsson, PhD, Olof Stephansson, MD, PhD, Stefan Johansson, MD, PhD, and Cecilia Magnusson, MD, PhD, all of whom hold academic positions at the Karolinska Institutet.
