Court Holds Daubert Hearing in Tylenol Autism Multidistrict Litigation 

Court Holds Daubert Hearing in Tylenol Autism Multidistrict Litigation 

Parties in the ongoing Tylenol product liability litigation are slated to participate in oral arguments before the Southern District of New York to determine the admissibility of expert testimony. The December 7 hearing will resolve extensive disputes between the defense and prosecution over the reliability and relevance of the medical evidence submitted to the court. 

At the center of the Tylenol lawsuits is the hotly contested claim that prenatal acetaminophen exposure can increase a child’s likelihood of developing autism and ADHD. Although plaintiffs have submitted compelling medical literature, Johnson and Johnson and other defendants have vociferously objected to the credibility of the research. 

Upon the conclusion of the Daubert hearing, the court will likely prepare for the selection of bellwether trials, which could have a profound impact on pretrial settlement negotiations.

Johnson and Johnson Attempts to Exclude Expert Testimony  

The chief defendant in the Tylenol lawsuits is Johnson and Johnson, the manufacturer of the staple pain reliever. In recent months, the company and other defendants have routinely sought to dismiss or derail the legal proceedings in the active multidistrict litigation. 

The latest effort targeted the plaintiffs’ experts in a September Rule 702 motion, which requested that the court exclude 5 of the prosecution’s scientific authorities on the grounds that they presented unreliable evidence or were themselves unreliable individuals. A subsequent court filing moved to establish nearly ninety hours of “direct, cross, redirect, and/or recross examination” of all parties’ experts. 

The plaintiffs’ counsel responded with a critical court filing in which they alleged that the costs and time associated with such proceedings were unnecessary and excessive. The presiding judge, Denise L. Cote, issued a brief hearing order on November 7 which established an early December Daubert hearing. 

What Are Daubert Hearings? 

In the pivotal case Daubert v. Merrell Dow Pharmaceuticals, Inc., the Supreme Court promulgated criteria governing the admissibility of scientific research and expert testimony in litigation. The decision requires that expert testimony be rooted in “scientific knowledge” and enshrines a “standard of evidentiary reliability”. 

In effect, parties must guarantee that their experts are qualified, reliable, and helpful in substantiating important medical or scientific allegations. Moreover, Daubert holds that experts cannot rely on personal speculation or suspicion but must cite or qualify authoritative literature. 

Daubert hearings are the procedural mechanism by which courts determine whether parties and their experts abide by the standards of the Supreme Court’s ruling. In resolving disputes, presiding judges act as the arbitrators and final authorities on the admissibility of scientific evidence. 

As Judge Cote determines the clinical literature investigating the link between prenatal Tylenol use and autism or ADHD, she will consider several fundamental questions, including:

  • Has the theory been tested? 
  • Has the tested theory been subject to peer review? 
  • What is the actual or possible rate of error? 
  • Does the relevant scientific community accept the theory or its methodology? 

Bellwether Trials in Tylenol Autism Litigation 

Upon the conclusion of the Daubert hearing in the Tylenol autism lawsuits, the court will likely direct parties to prepare for bellwether trial selection. In multidistrict litigation, bellwether trials signal to parties the receptiveness of juries to the proposed claims and the potential compensation courts may award to successful plaintiffs. Consequently, they have a direct impact on pretrial settlement negotiations. 

In sweeping MDLs, courts select a series of representative cases whose circumstances are similar to other plaintiffs participating in the litigation. Some courts rely upon randomized computer-generated picks and others permit the parties to make selections that the court approves or rejects. Judge Cote has not signaled how she intends to structure the bellwether selection process. 

Scientific Evidence Linking Prenatal Tylenol Exposure to Autism, ADHD

Although defendants have extensively criticized the scientific basis of plaintiffs’ claims, a growing body of clinical research has definitively linked prenatal Tylenol exposure to serious conditions including autism spectrum disorder and attention-deficit/hyperactivity disorder. 

Some of the most common studies plaintiffs cite to substantiate their claims include: 

2015 Study from Danish Epidemiology Science Centre

Researchers from the Danish Epidemiology Science Centre relied upon an expansive birth cohort database to investigate the link between prenatal acetaminophen exposure and ASD. Following 64,322 children and mothers, the 2015 study discovered that gestational acetaminophen use could result in an “increased risk of ASD accompanied by hyperkinetic symptoms”. 

In addition, the study noticed a stronger correlation between APAP (acetaminophen) and ASD in children who had sustained higher levels of exposure during gestation. 

2017 Survey of Norwegian Patient Registry Data

Another scientific dispute between plaintiffs and defendants pertains to the genetic predisposition of ASD in children whose mothers consumed Tylenol during pregnancy. Although confounding variables are difficult to isolate entirely, a 2017 survey concluded that long-term gestational acetaminophen use was “substantially associated with ADHD” in spite of “potential confounders”. 

The study relied upon accessible information from the Norwegian Patient Registry and ultimately included 112,973 offspring. After adjusting for “indications of use” and “familial risk of ADHD”, researchers identified a negative association between short-term Tylenol use and ADHD but a heightened risk for children who sustained long-term exposure. 

2019 Johns Hopkins University Birth Cohort Study 

Johns Hopkins researchers further confirmed earlier suspicions about the Tylenol-autism link in a 2019 study that followed the neurodevelopment of 996 mother-child dyads over twenty years. Relying upon self-reporting data, the study concluded that children whose umbilical cords displayed higher levels of acetaminophen at birth were at a “significantly increased risk of childhood ADHD and ASD”. The most important revelation of the study was the dose-dependent relationship between prenatal Tylenol exposure and neurodevelopmental complications. 

2021 Analysis from the European Journal of Epidemiology 

An additional birth cohort study from the European Journal of Epidemiology analyzed data from 6 cohorts and 73,881 mother-child pairs. Researchers accounted for maternal indications of acetaminophen and child characteristics. 

Ultimately, the analysis concluded that children who sustained prenatal acetaminophen exposure were 19% more likely to develop borderline or clinical Autism Spectrum Conditions (ASC) and 21% more likely to develop ADHD symptoms. Researchers further suggested that pregnant women be fully informed of these risks, indicating the growing alarm in the medical community in the lead-up to Tylenol-acetaminophen litigation. 

2021 Consensus Statement from Yale Researchers

In 2021, thirteen researchers published a consensus statement warning of the risks of prenatal Tylenol exposure. The statement asserts that extant medical literature strongly indicates a potential link between acetaminophen and neurodevelopmental and urogenital disorders. 

Ninety-one researchers signed the statement, which encourages greater education of expecting mothers on the risks of gestational acetaminophen use and has since spurred additional investigations. 

Federal Panel Consolidates Tylenol Autism Lawsuits 

In the aftermath of alarming acetaminophen studies, Johnson and Johnson and other manufacturers were listed in a series of product liability lawsuits that targeted their failure to warn pregnant women of the risks of Tylenol use. Several plaintiffs ultimately filed a petition with the U.S. Judicial Panel on Multidistrict Litigation (JPML), which determines whether or not to consolidate similar cases for pretrial proceedings in federal court. 

The JPML granted plaintiffs’ request and established a Tylenol autism multidistrict litigation, which it transferred to the U.S. District Court for the Southern District of New York. The recent disputes over expert testimony come at the conclusion of the crucial discovery process, during which parties collect evidence substantiating their claims. 

As of December 2023, nearly 450 Tylenol autism lawsuits have enrolled in the MDL, and the number is expected to grow in the aftermath of the Daubert hearing. 

Common Damages in Tylenol Autism Lawsuits 

The manufacturers of name-brand and generic acetaminophen had a responsibility to inform consumers of the risks their products posed. Instead, they either ignored or discounted authoritative medical evidence and failed to warn users of the various complications associated with prenatal acetaminophen exposure. 

As a result, families across the country have had to contend with avoidable neurodevelopmental complications in their children. Fortunately, plaintiffs in Tylenol autism lawsuits reserve the right to seek compensation for their losses in the form of economic and non-economic damages addressing:

  • Medical costs — past, present, and future 
  • Out-of-pocket expenses 
  • Lost wages or income 
  • Pain and suffering 
  • Decreased quality of life 
  • Mental anguish 

Although numerous online services claim to provide immediate and accurate compensation estimates, they fail to account for the unique circumstances of an individual’s claim or offer holistic assessments. The best way by to determine case value for your Tylenol autism claim is to speak with an experienced product liability lawyer today. 

Contact an Experienced Tylenol Autism Lawyer Today

Acetaminophen manufacturers’ failure to warn pregnant women of the risks inherent in prenatal APAP exposure represents a gross betrayal of public trust. Whenever massive pharmaceutical companies abjure their responsibility to consumers, we are on standby to pursue justice and accountability.

In a free consultation, our qualified Tylenol autism lawyers can explain the eligibility of your claim, calculate the compensation to which you and your family may be entitled, and assist you in making the important decision to file suit. With over 120 combined years of personal injury law experience and extensive familiarity with the complex process of enrolling and participating in MDLs, we have a proven track record of success and a steadfast commitment to defending our clients’ rights as they tend to their families’ needs.

For more information, contact us today. 


Matthew Dolman

Personal Injury Lawyer

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 of $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.

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