photo of worried pregnant woman

Tylenol Autism Lawsuits Claim Prenatal Use Increases Risk

December 18, 2023 Update

On December 18, 2023, Judge Cote issued an opinion and order that precludes the testimony of plaintiffs’ general causation experts. The court stated, “With these rulings, the plaintiffs do not have admissible evidence to demonstrate that prenatal exposure to acetaminophen causes either ASD or ADHD in offspring.” This ruling effectively ends these cases and any chance at putting forth evidence at trial. At this time, it is unclear if plaintiffs will appeal this ruling.

Tylenol® (acetaminophen, paracetamol) is an iconic medical brand and drug considered safe and effective for various ailments, like fever, headaches, and body aches.

Millions of Tylenol doses are taken daily, with some estimates that almost 25% of U.S. adults use an acetaminophen-based drug weekly.

For decades, doctors told pregnant women that Tylenol and other acetaminophen-based products were safe to use. Acetaminophen-based products have long been marketed to expectant mothers as the only safe prenatal pain reliever and fever reducer.

Tylenol’s marketing was effective as studies show that at least 50% of pregnant women in the U.S. use acetaminophen-based medications during pregnancy.

Tylenol Autism Lawsuits

Based on a growing body of scientific research, parents of autistic children have started filing product defect lawsuits against the manufacturers of Tylenol and other acetaminophen-based medicines.

These injury lawsuits claim that manufacturers and distributors of acetaminophen-based drugs knew, or should have known, of the link between prenatal acetaminophen use and the increased risk of neurological disorders such as autism but instead continued marketing the drugs without warning pregnant women of the risks.

The defendants named in the Tylenol autism lawsuits include the primary manufacturers of acetaminophen-based products and major drug retailers like Walgreens, CVS, Walmart, Rite Aid, Target, and Costco, most of whom sell and market their own branded acetaminophen-based products.

Tylenol Autism Lawsuit Injuries

The primary injuries alleged in the Tylenol autism lawsuits are neurodevelopmental disabilities associated with the prenatal use of Tylenol and acetaminophen.

Autism Spectrum Disorder (ASD) and Attention Deficit / Hyperactivity Disorder (ADHD) are the neurodevelopmental disorders most commonly linked to prenatal Tylenol use. However, studies have indicated several other adverse health consequences may also be related to Tylenol use in pregnant women.

Some common neurodevelopmental disorders alleged in the Tylenol austims lawsuits include:

  • Autism / Autism Spectrum Disorder (ASD)
  • Attention Deficit / Hyperactivity Disorder (ADHD)
  • Asperger’s Syndrome (a form of autism)
  • Lower IQ levels
  • Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS), including “Atypical Autism”
  • Cerebral palsy (CP)
  • Oppositional defiant disorder (ODD)
  • Neurodevelopmental problems like language delays
  • Fertility issues in males

Several studies have found that acetaminophen use during pregnancy increases the risk that an unborn child will have various other neurodevelopmental problems, including decreased IQ, cerebral palsy, language delays, and oppositional defiant disorder.

Currently, our firm accepts only autism spectrum disorder cases, including Asperger’s Syndrome and PDD-NOS.

We believe the medical literature on the link between prenatal Tylenol or acetaminophen use and autism is more developed and has fewer methodological limitations than studies regarding other potential acetaminophen-linked neurodevelopmental injuries.

Our autism injury requirement may change as evidence is uncovered in the lawsuits, and additional scientific studies are published.

Acetaminophen-Based Drugs in the Tylenol Autism Lawsuits

Although often called the “Tylenol lawsuits,” the growing litigation includes most over-the-counter medications containing acetaminophen or paracetamol. Here is a list of some of these acetaminophen-based medications:

  • Tylenol® / acetaminophen
  • Nyquil®
  • Dayquil®
  • Alka-Seltzer Plus®
  • Excedrin®
  • Midol®
  • Mucinex®
  • Coricidin HBP®
  • Robitussin Maximum Strength®
  • Sinex®
  • Sudafed®
  • Theraflu®
  • Store-branded acetaminophen products such as Walmart’s Equate® products

The above list is not exhaustive, as dozens of other acetaminophen and paracetamol-based medications exist.

Status of the Tylenol Autism Lawsuits

On October 5, 2022, the federal Judicial Panel on Multidistrict Litigation (JPML) consolidated all Tylenol lawsuits in the U.S. District Court for the Southern District of New York. The cases, now titled In Re: Acetaminophen-ASD/ADHD Products Liability Litig. (MDL No. 3403) was assigned to the Honorable Denise L. Cote.

As of January 17, 2023, over 100 individual lawsuits have been filed or transferred into MDL 3403. Hundreds of additional cases are expected to be filed in the next six months.

Consolidation in mass tort injury lawsuits like this is essential. Instead of having dozens, if not hundreds, of courts overseeing the same general discovery matters and ruling on the same pre-trial motions, the cases will be assigned to one judge to oversee the pre-trial phase. This conserves judicial resources, prevents inconsistent court rulings, and lets plaintiffs share the cost of litigation.

Judge Cote has extensive experience overseeing mass tort consolidations like the Tylenol autism lawsuits and has entered several necessary pre-trial orders that have rapidly moved the litigation forward.

The court has entered a direct filing order and approved a short-form complaint to let cases be directly filed into the Tylenol autism lawsuit MDL.

Judge Cotes also denied a significant motion to dismiss by Walmart, requesting the court dismiss all cases naming Walmart as a defendant on preemption grounds. The court’s swift action in directing all parties to brief this critical legal issue and issuing an order denying Walmart’s motion was impressive. It reflected the court’s intent to move this complex litigation forward quickly.

On December 18, 2023, Judge Cote issued an opinion and order that precludes the testimony of plaintiffs’ general causation experts. The court stated, “With these rulings, the plaintiffs do not have admissible evidence to demonstrate that prenatal exposure to acetaminophen causes either ASD or ADHD in offspring.” This ruling effectively ends these cases and any chance at putting forth evidence at trial. At this time, it is unclear if plaintiffs will appeal this ruling.

Studies Linking Tylenol Use During Pregnancy to Autism Risk

In the past few years, however, several scientific articles have been published linking prenatal acetaminophen exposure to neurodevelopmental problems, including autism and attention-deficit / hyperactivity disorder.

Since 2000, the number of U.S. children diagnosed with autism spectrum disorder has increased exponentially.

In 2000, the CDC reported that the prevalence of autism was 6.7 cases out of every 1,000 children or 1 in 150 children. By 2010, the reported prevalence had more than doubled to 1 in 68 children.

By 2018, it had grown to 1 in 44 children. A similar increase in the incidence of ADHD has been seen.

The increasing incidence of autism and ADHD in U.S. children has led to significant scientific research into the potential cause.

Johns Hopkins Boston Birth Cohort Study

In October 2019, the results of a Johns Hopkins study funded by the National Institutes of Health were published in JAMA Psychiatry. The study suggested acetaminophen use during pregnancy is linked to higher rates of autism spectrum disorder and ADHD.

The study involved the collection of umbilical cord blood from 996 patients and measured the amount of acetaminophen in each sample. At an average age of 8.9 years, 25.8% of the children had been diagnosed with ADHD only, 6.6% with autism, and 4.2% with autism and ADHD.

The study also identified a dose-response association where the increased use of acetaminophen over a longer period of pregnancy results in an increased risk of autism and ADHD.

The researchers classified the amount of acetaminophen and its byproducts in the samples into thirds, from lowest to highest. Compared to the lowest third, the middle third of exposure was associated with about 2.26 times the risk for ADHD.

The highest third of exposure was associated with 2.86 times the risk. Similarly, the autism risk was higher for those in the middle third (2.14 times) and highest third (3.62 times).

2018 Systematic Review of Cohort Studies

In August 2018, the results of a Systematic Review, Meta-Analysis, and Meta-Regression Analysis of Cohort Studies appeared in the American Journal of Epidemiology.

The study was to evaluate the risk of autism and ADHD in the children of women who used acetaminophen prenatally. The review analyzed seven retrospective cohort studies and found that acetaminophen use during pregnancy is “significantly associated with an increased risk for ASD [autism] and emotional problems” and the development of hyperactivity symptoms such as ADHD.

Specifically, the review found that acetaminophen use during pregnancy resulted in a 20% increased risk of autism and a 30% increased risk of ADHD.

Other Studies Linking Prenatal Acetaminophen Use to Autism

Several other studies have also identified a link between acetaminophen use during pregnancy and the risk of autism. The results of a Spanish birth cohort study of over 2,600 mother-child pairs appeared in the December 2016 edition of the International Journal of Epidemiology.

The study results, appearing in a journal article titled “Acetaminophen use in pregnancy and neurodevelopment: attention function and autism spectrum symptoms,” found an independent association between prenatal acetaminophen use and autism spectrum symptomatology in exposed children. The study also found that this association was more significant in male than female children.

The results of a massive cohort study of over 60,000 children and mothers enrolled in the Danish National Birth Cohort were reported in the December 2015 edition of Autism Research. The results were published in an article titled “Maternal use of acetaminophen during pregnancy and risk of autism spectrum disorders in childhood: A Danish national birth cohort study.” The Danish study found that prenatal use of acetaminophen was associated with autism and that a longer duration of acetaminophen use increased the risk almost twofold.

The article “Prenatal paracetamol exposure and child neurodevelopment: a sibling -controlled cohort study” was published in the October 2013 edition of the International Journal of Epidemiology. The article published the results of a study that found children exposed to long-term use of paracetamol during pregnancy “had substantially adverse developmental outcomes at three years of age.”

91 Scientists and Health Professionals Demand Action

A Call to Action on Acetaminophen Use During Pregnancy

A call to action about the relationship between prenatal acetaminophen use and autism spectrum disorder appeared in the September 2021 edition of Nature Reviews Endocrinology.

The Consensus Statement by 91 scientists, clinicians, and health professionals discussed the long list of scientific research on the link between acetaminophen use during pregnancy and autism and made several strong recommendations.

The Consensus Statement notes that a growing body of scientific research finds:

Prenatal exposure to paracetamol (APAP or acetaminophen) might alter fetal development, which could, in turn, increase the risks of certain neurodevelopmental, reproductive, and urogenital disorders. Here we summarize this evidence and call for precautionary action through a focused research effort and by increasing awareness among health professionals and pregnant women.

…We recommend that pregnant women should be cautioned at the beginning of pregnancy to: forego APAP [acetaminophen] unless its use is medically indicated; consult with a physician or pharmacist if they are uncertain whether use is indicated and before using on a long-term basis; and minimize exposure by using the lowest effective dose for the shortest possible time. (emphasis added)

These experts also made the following recommendations about Tylenol and acetaminophen use before and during pregnancy:

  1. Pregnant women should be counseled before or during pregnancy to avoid Tylenol or acetaminophen use unless medically necessary and to reduce their risk by using the lowest effective acetaminophen dosage for the shortest possible time.
  2. All acetaminophen-based medications, despite the country, should have warnings regarding use during pregnancy.
  3. The U.S. Food and Drug Administration and European Medicines Agency “should review the most recent research and issue an updated Drug Safety Communication” on acetaminophen use during pregnancy.

Tylenol Autism Lawsuit FAQ

Does Tylenol’s autism risk increase with use?

The risk of autism appears to be “dose related.” The increased risk of a child developing autism seems correlated to the timing, amount, and length of Tylenol or acetaminophen use. The more Tylenol or acetaminophen ingested during pregnancy, the higher the risk of the child developing autism.

Researchers know that acetaminophen from a mother’s blood can enter the baby’s bloodstream via the placenta and cross the blood-brain barrier, a barrier of brain cells designed to prevent specific solutes in the bloodstream from crossing over into the central nervous system.

Despite this knowledge, the mechanism of acetaminophen’s impact on fetal brain development is not fully understood. Some studies have found acetaminophen to be an “endocrine disruptor” that inhibits the proper distribution of hormones and other chemicals critical to prenatal development. Inhibiting these essential hormones and chemicals may cause neurodevelopmental problems in fetal brains.

Animal studies have shown that acetaminophen use has direct neurotoxic effects in cortical neurons and inhibits fetal testosterone production in mice, both vital for neurologic development.

A fetus’s developing brain is vulnerable to neurodevelopmental problems caused by chemicals. This makes it critically important that medications ingested during pregnancy be proven safe for the developing fetus.

The primary legal claims in the Tylenol autism lawsuits are those often seen in other drug and pharmaceutical product liability lawsuits. Complaints in the Tylenol lawsuits include claims for strict liability failure to warn and design defects, negligent failure to warn and design defects, breach of express and implied warranties, misrepresentation, concealment of material facts, and violations of state consumer protection laws.

How long do I have to file a Tylenol autism lawsuit?

How much time a person has to file a legal claim depends on the statute of limitations that applies to the allegations and specific facts of each case. Most states generally have a two or three-year statute of limitations, and several legal doctrines may toll or extend the statute of limitations in some instances.

For example, when the injured party is a child, the statute of limitations is usually tolled until the child reaches the age of majority (usually 18 or 19 years old in most states). Under this doctrine, the statute of limitations starts to run once the child reaches the age of majority.

Other legal doctrines, like the discovery rule, can also extend the statute of limitations. So, even if your child or family member was diagnosed with autism many years ago, a civil claim for damages may still exist.