Can Tylenol Cause Autism?

January 3, 2023
Can Tylenol Cause Autism?

Can Tylenol Cause Autism? Acetaminophen Linked to Autism

Tylenol use (or use of generic acetaminophen) by pregnant women has now been the subject of over twenty-six (26) epidemiological studies. All twenty six studies found an association between in utero acetaminophen (commonly sold under the brand name Tylenol) exposure and a diagnosis of autism spectrum disorder or ADHD (attention deficit hyperactivity disorder).

In September of 2021, a consensus statement signed by ninety-one (91) scientists appeared in the medical journal, Nature Reviews Endocrinology called for pregnant women to exercise precaution in acetaminophen use during pregnancy. In this article we will discuss the body of scientific evidence and emerging research linking Tylenol use to autism spectrum disorder. Please note the FDA has not formally reviewed recent studies concerning in utero acetaminophen exposure in several years.

Keep in mind a reported 70% of pregnant women use acetaminophen products during pregnancy for pain relief or fever. Acetaminophen is an active ingredient in over 600 medications including the following: Alka-Seltzer Plus, Actifed, Cepacol, DayQuil, Excedrin, Mucinex, NyQuil, Robitussin, Sudafed and Tylenol.

We now have a body of science that provides compelling evidence this common pain reliever can pose danger to the developing fetus and has commonly been associated with adverse neurodevelopmental conditions.

Medical Studies Linking Tylenol to Autism Spectrum Disorder & ADHD

Consensus Statement Signed by 91 Scientists and Physicians

consensus statement issued in 2021, was essentially a call to action as researchers could no longer ignore the overwhelming scientific evidence indicating acetaminophen use during pregnancy could cause autism spectrum disorder or attention deficit hyperactivity disorder (ADHD).

The authors stated “the combined weight of animal and human scientific evidence is strong enough for pregnant women to be cautioned by health professionals against its indiscriminate use, both as a single ingredient and in combination with other medications.”

The use of acetaminophen during pregnancy is an issue that has not received proper attention despite consistent association demonstrated by study after study. This may have something to do with the anti-vaccine movement and the discredited and debunked science behind the vaccine-autism link. We fear the stigma associated with such has resulted in lack of attention to the danger of regular acetaminophen exposure during pregnancy.

Acetaminophen has long been considered safe to use during pregnancy and is the active ingredient in over 100 medications. In fact, acetaminophen has been shown to be effective in treating minor to moderate pain as well as low grade fever.

However, emerging research across twenty-six epidemiological studies and numerous animal studies demonstrates what many researchers believe to be a causal link between in utero acetaminophen exposure and autism spectrum disorder.

Prenatal Tylenol use Poses a Large Risk

Can Prenatal use of Tylenol Cause Autism?

The authors of the consensus statement on acetaminophen and autism, believe that prenatal and perinatal use or exposure to acetaminophen can negatively impact fetal brain development. In fact, the writers state “consistent with the epidemiological data, studies have demonstrated that the strongest effects of long-term use and exposure occur at a time equivalent to the beginning of the third trimester of pregnancy and the time around birth in humans.”

Finally, the authors state, “We as a society should be able to take protective action when scientific evidence indicates a chemical is of concern, and not wait for unequivocal proof that a chemical is causing harm to our children. Evidence of neurodevelopmental toxicity of any type — epidemiological or toxicological or mechanistic — by itself should constitute a signal sufficient to trigger prioritization and some level of action.”

Again, the main concern of researchers, is the adverse impact of acetaminophen on fetal brain development. A medical body of evidence consisting of a decade's worth of studies linking Tylenol to autism and child development was no longer something to be ignored. Further, new scientific research discussed in this article only increases the confidence of researchers concerning the link between Tylenol and autism.

The scientists who penned this study referenced that the use of acetaminophen may be necessary for pregnant women in specific situations. However, they cautioned that using generic acetaminophen products or Tylenol regularly as opposed to brief instances is what concerned them.

In other words, the stressed that Obstetricians should counsel pregnant women that use of acetaminophen products during pregnancy should be for as brief a period of time as possible at the lowest possible dosage.

European Journal of Epidemiology (2021)

Researchers analyzed data of 73,881 children via six previous birth cohort studies. This study on prenatal and postnatal exposure to acetaminophen appeared in the European Journal of Epidemiology. The analyses of the studies demonstrated that children with prenatal exposure to Tylenol/acetaminophen had a statistically significant increase in the diagnosis for autism spectrum disorder and ADHD.

This study showed a clear link between use of acetaminophen by pregnant women and a child's risk for autism spectrum disorder and/or ADHD diagnosis. This is yet another study finding acetaminophen use during pregnancy associated with autism spectrum disorder. In utero acetaminophen exposure has been shown to be associated with autism spectrum disorder.

An important distinction to be made, is the researchers did not find any association between postnatal generic acetaminophen exposure and autism or ADHD. The findings of an increased rate of autism and ADHD were consistent only for prenatal use of acetaminophen.

Johns Hopkins University Boston Birth Cohort (2019)

2019 study published in the scientific journal, JAMA Psychiatry; found cord biomarkers (umbilical cord blood samples) of fetal acetaminophen exposure was associated with a significantly increased rate of autism spectrum disorder and ADHD in a “dose response fashion.” In other words, the greater the amount of acetaminophen found within umbilical cord blood samples the greater the incidence rate of autism spectrum disorder or ADHD diagnosis. This is known as the Johns Hopkins University Boston Birth Cohort study. This adds greater credence to the claim that regular use of Tylenol while pregnant could present problems.

If nothing else, the Johns Hopkins University Bloomberg School of Public Health study, established in utero exposure to acetaminophen increased a child's risk for autism spectrum disorder and attention deficit hyperactivity disorder as well as other neurodevelopmental disorders.

This was a twenty (20) year study of pregnant women and early life factors of their children. The researchers measured biomarkers for acetaminophen within the umbilical cord blood samples in 996 separate births.

Babies with the highest level of acetaminophen in their umbilical cord blood samples were three times more likely to be diagnosed with autism spectrum disorder or ADHD later on in life as compared to infants with the lowest level of acetaminophen.

Additionally, researchers found a consistent association between acetaminophen found within biomarkers of cord blood samples and autism spectrum disorder and ADHD across a number of confounding factors including preterm birth, substance abuse, smoking, maternal stressors and maternal BMI. The dose response findings support the working theory that Tylenol adversely impacts fetal development.

The lone criticism of this study is researchers had to rely on self-reporting of the mothers which is not always ideal. There are ethical reasons that pose a limitation to scientists performing more than observational studies on a pregnant woman. It would be unethical to purposely subject pregnant women to a known health risk.

Recall bias and no objective measure for tracking in utero exposure to acetaminophen during specific periods of pregnancy are the lone drawbacks to this particular study. In other words, there was no specific method to track exactly how much acetaminophen a pregnant women took during her pregnancy. It is crucial to view these studies in their totality as a cumulative body of science.

Acetaminophen use in Pregnancy and Neurodevelopment (2016)

In a 2016 study published in the International Journal of Epidemiology, researchers analyzed 2644 mother-child pairs. They analyzed children at age one and five to determine whether prenatal exposure to acetaminophen lead to an increased risk for autism spectrum disorder or ADHD. Researchers found a clear connection and increased risk between Tylenol use during pregnancy and autism.

This study was unique for finding an association between Tylenol use and autism dependent on the frequency of exposure to acetaminophen during pregnancy. This finding was repeated with much greater clarity in the aforementioned Johns Hopkins Boston Birth Cohort study which again showed a dose response fashion finding based on the overall use of acetaminophen.

Danish National Birth Cohort Study (2015)

Maternal use of Acetaminophen Analyzed During Pregnancy as a Risk Factor for Autism Spectrum Disorder

Researchers analyzed 64,322 mother-child pairs over 12.7 years to better understand the cause of diseases in children. This study specifically analyzed acetaminophen use during pregnancy to determine whether there was an association with an increased rate of autism spectrum disorder in offspring.

Scientists found in utero exposure to acetaminophen had an adverse effect on fetal development and lead to a significant increase in diagnosis for ADHD and a notable increase in autism spectrum disorder.

JAMA Psychiatry Study (2014)

Another research team analyzed the Danish national birth cohort study that was conducted between 1996 – 2002. Scientists again found an increase in both ADHD and hyperkinetic disorder (abnormal involuntary movements), which is a severe form of ADHD following in utero exposure to Tylenol/acetaminophen exposure

Acetaminophen Exposure and Fetal Brain Development

The Yale University School of Public Health also published the findings echoed by 91 scientists in the aforementioned consensus statement. Zeyan Liew, Ph.D, M.P.H., professor at the Yale University School of Public Health states that Yale's lab was among the first to report a detrimental effect of acetaminophen use during pregnancy and acetaminophen exposure on fetal brain development.

It is worth noting the authors of the previously referenced consensus statement relied on twenty-five (25) years of epidemiological, animal and in vitro studies in arriving at their conclusions. The research team found an increased risk for neurodevelopmental disorders such as autism spectrum disorder, attention deficit hyperactivity disorder, decreased IQ and language delays. It turns out, this common pain reliever is consistently

Acetaminophen has been shown to cross the placental barrier and is theorized to cause alterations to maternal hormones and detrimentally impact fetal development.

2022 Animal Study of Tylenol use and Fetal Brain Development

Does Tylenol Cause Autism?

Consistent with the totality of animal studies, in Paracetamol (Acetaminophen) and its Effect on the Developing Mouse Brain, researchers found that mice exposed to relevant doses of acetaminophen (meant to mimic regular use of Tylenol as opposed to mere occasional use) displayed reduced memory and learning ability and other signs of neurodevelopmental disorders. It appeared to the scientists that Tylenol induces oxidative stress in the hippocampus which likely plays a large role in the manifestation of neurodevelopmental issues.

The question remains; what pain relievers will pregnant women have available in the future. Among all pain relievers, Tylenol has long been thought to be safe for consumptions by pregnant women.

Clearly more research must be conducted in this area for the safety of pregnant women and their children. However, maternal use of acetaminophen products pose a higher risk for neurodevelopmental disorders such as autism. The studies clearly demonstrate children exposed to environmental conditions in utero and perinatal, along with genetics pose as risk factors for the potential to develop autism.

Please note that we are NOT stating that Tylenol causes autism.  Rather, we believe that the regular use of Tylenol by pregnant women throughout large periods of a pregnancy poses an increased risk of a child subsequently being diagnosed with autism spectrum disorder.  We believe it is “a cause” as opposed to “the cause.”

Our Tylenol autism lawyers are currently taking clients with children that have developed health issues related to exposure to acetaminophen while in the womb. Dolman Law Group is a personal injury law firm that provides award-winning legal representation to those harmed by defective medical products. Contact us today for a free consultation to learn how we can help you.

Dolman Law Group's History with the Tylenol Autism Lawsuits

Our law firm began investigating claims relating to the link between using acetaminophen while pregnant and autism spectrum disorder as early as last summer. We were one of the first law firms involved and now represent nearly 1000 clients with claims or lawsuits against the manufacturers of Tylenol (Johnson & Johnson) and generic acetaminophen products. Further, we also a part of the legal team with claims or lawsuits against retailers such as CVS, Walmart, Walgreens, Costco and others for failing to warn pregnant women over the dangers of consuming acetaminophen during pregnancy and the risks it may pose to a developing fetus.

If you have a child diagnosed with autism spectrum disorder or ADHD and you used acetaminophen products during your pregnancy, please call us immediately. Our attorneys offer a free consultation and case review to determine whether you are qualified. The Dolman Law Group actively represented injured consumers in product liability lawsuits and mass tort cases. We will continue playing a role in the national Tylenol lawsuit and you can check this site as well for updates:  

Matthew Dolman

Clearwater Personal Injury and Insurance Attorney

This article was written and reviewed by Matthew Dolman. Matt has been a practicing civil trial, personal injury, products liability, and mass tort lawyer since 2004. He has represented over 11,000 injury victims and has served as lead counsel in over 1000 lawsuits. Matt is a lifetime member of the Million Dollar Advocates Forum and Multi-Million Dollar Advocates Forum for resolving individual cases in excess or $1 million and $2 million, respectively. He has also been selected by his colleagues as a Florida Superlawyer and as a member of Florida’s Legal Elite on multiple occasions. Further, Matt has been quoted in the media numerous times and is a sought-after speaker on a variety of legal issues and topics.

Learn More