Navigating the Risks of Tylenol in Pregnancy: Understanding the Connection to Autism and ADHD

Naheed Ali, MD, PhD

Pregnant women often take Tylenol, a brand name for the drug acetaminophen, to alleviate common pregnancy discomforts such as headaches, fever, and pain. However, a recent study has shown that taking Tylenol during pregnancy may increase the risk of autism and attention-deficit hyperactivity disorder (ADHD) in children. In this article, we’ll explore the research linking Tylenol use during pregnancy to these developmental disorders and discuss the potential implications for expectant mothers.

Overview of Tylenol

Tylenol is a common over-the-counter pain reliever and fever reducer. It is used for a number of ailments including headaches, aching muscles, cramping during menstruation, and the common cold. It works by blocking the production of certain body chemicals that are responsible for pain and inflammation.

The US Food and Drug Administration (FDA) has set a maximum daily dose of 4,000 milligrams per day for adults and 90 milligrams per kilogram per day for children. The FDA also requires that all OTC products containing acetaminophen have a warning on the label about the potential risk of liver damage from ingesting too much of the medication.

Tylenol under scrutiny

Most of the lawsuits that have been filed against Tylenol are related to the marketing of the product. In 2020, the corporation behind Tylenol, Johnson & Johnson, settled a lawsuit for $6.3 million for false packaging claims that bottles of Infant’s Tylenol were uniquely or specially formulated for infants when in truth, the bottles contained the same concentration as that of Children's Tylenol.

Tylenol has also come under fire for its inclusion of titanium dioxide, among other potentially dangerous food coloring additives. Titanium dioxide, a whitening and opacifying agent, is a type of nanoparticle, meaning that it is extremely small. When consumed, these small particles may be able to penetrate cell membranes and enter the body's organs and tissues. It is also a potential carcinogen, meaning it can cause the materialization of cancerous tumors within the body.

More recently, Johnson & Johnson has fallen under scrutiny for failing to warn against the risks of Tylenol use among pregnant women, especially those who are further along in their pregnancy. Numerous Tylenol cases for autism and ADHD have already been filed in the US, but as of yet, none of them have been amalgamated into a multidistrict litigation or a class action lawsuit.

Results from the Boston Birth Cohort

Long-term research on mothers and their children has been conducted since 1998 as part of the Boston Birth Cohort. Conducted by the Boston University School of Public Health and the Boston Medical Center, the study aims to investigate the environmental and genetic factors that contribute to the development of chronic diseases in children. It enrolls pregnant women during their first prenatal visit and follows them and their children through pregnancy, childbirth, and early childhood. The study collects data on a wide array of factors that may affect child development, including maternal health, prenatal exposures, nutrition, and social and economic status.

The researchers collected blood samples from the umbilical cords of 996 babies at birth and measured the amount of acetaminophen and some of its byproducts in each sample. When the children were around 9 years old, it was found that 25.8% of them had been diagnosed with ADHD, 6.6% with autism, and 4.2% with both ADHD and autism.

The researchers also found that children whose mothers had higher levels of acetaminophen in their blood during pregnancy were more likely to be diagnosed with ADHD and autism. Specifically, the children whose mothers had the highest drug levels in their blood were 2.86 times more likely to have ADHD and 3.62 times more likely to have autism, as compared to the children of the mothers who had the lowest levels.

How does Tylenol increase the risk of autism and ADHD?

The mechanisms by which Tylenol may cause autism and ADHD are not fully understood. The studies that have suggested a link between acetaminophen use during pregnancy and these developmental disorders have demonstrated an association but failed to establish a cause-and-effect relationship.

It’s believed that acetaminophen may affect the development of the brain and the nervous system in the unborn child. Some studies have suggested that acetaminophen may alter the levels of certain neurotransmitters, such as dopamine and serotonin, which play a role in brain development and behavior.

Acetaminophen is also known to have an effect on the body's oxidative stress and inflammation, which may also play a role in the development of autism and ADHD. Some studies have suggested that acetaminophen may affect the development of the cerebellum, a part of the brain widely acknowledged for motor coordination and balance, as well as social and emotional behavior.

Despite the lack of causal evidence, it's important for Tylenol's manufacturer to still warn against any potential risks because pregnant women are a vulnerable population and have unique medical needs. They have a responsibility to bestow accurate and up-to-date information about the safety of their products to protect the health of their consumers.

At this point, you may be wondering how a simple warning could have helped mothers. Had there been warnings about the potential risks associated with Tylenol use during pregnancy, expectant parents would have been able to arrive at informed decisions about whether or not to use the medication before pregnancy. 

Women who want to refrain from using the medication could have consulted with their healthcare providers about alternative pain relief options that may be safer for them during pregnancy. For those who do choose to take the medication, these warnings would have made them aware of the potential risks linked to its usage and the steps they can take to minimize those risks, such as adhering to the recommended dosage and using the medication for only a certain point during their pregnancy.

Toward a safe pregnancy and birth

If you are a pregnant woman who is currently taking Tylenol, it is recommended that you consult with your healthcare provider about Tylenol use going forward. You may also inquire about other pain relief medications or methods that are more suited to your situation. Moreover, if you are a mother of a child who is diagnosed with autism or ADHD, and you believe that this might be due to Tylenol use during your pregnancy, we at Lawsuit Legit may be able to help. Fill up the form on the right side of your screen to get a pro bono evaluation of your case.

About the Author

Dr. Ali is a medical journalist and copywriter at

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10 Cited Research Articles

Our writers follow rigorous sourcing guidelines and cite only trustworthy sources of information, including peer-reviewed journals, court records, academic organizations, highly regarded nonprofit organizations, government reports and interviews with qualified experts.

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