Acetaminophen is one of the world’s most widely used over-the-counter pain relievers and fever reducers. Historically, scientists and doctors have considered it relatively safe for all ages, including pregnant women and infants. They mainly only cautioned about its overuse, causing potential liver damage. However, many medical studies conducted in the last few years have linked prenatal and postnatal use of acetaminophen to autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) in children. This blog post will delve into the growing body of evidence which explores these connections and discuss the potential legal implications for parents of affected children.

Acetaminophen and Its Increased Use

The prevalence of acetaminophen use increased dramatically in the 1980s after the Centers for Disease Control and Prevention (CDC) suggested consumers stop prenatal and pediatric aspirin use because of its association with a rare yet serious condition known as Reye’s syndrome. This shift in recommendations led to a surge in acetaminophen use by women during pregnancy and by parents giving it to infants.

Acetaminophen Use During Pregnancy and the Risk of Autism and ADHD

Prenatal exposure to acetaminophen has been a subject of extensive research, with multiple studies pointing towards an association between its use during pregnancy and an increased risk of autism and ADHD in children. A 2014 study by the University of California, based on data from over 64,000 mothers and children in the Danish National Birth Cohort, found that maternal acetaminophen use during pregnancy increased the risk of hyperkinetic (hyperactive) disorder, ADHD medication treatment, and ADHD-like behaviors in children by the age of 7. The risk was even higher for children whose mothers used acetaminophen for over 20 weeks during pregnancy.

A study published in the American Journal of Epidemiology in 2018 found that prolonged acetaminophen use during pregnancy was associated with a 20% greater risk of autism and a 30% greater risk of ADHD. Similarly, a study conducted by the University of Barcelona and published in the European Journal of Epidemiology in 2021 found that children exposed to acetaminophen in utero were 19% more likely to develop autism and 21% more likely to exhibit signs of ADHD.

A study conducted by Johns Hopkins University and published in 2019 in JAMA Psychiatry proclaimed that children with the most significant levels of acetaminophen in their umbilical cord blood were over 3.5 times more likely to be diagnosed with ASD and almost three times more likely to be diagnosed with ADHD. These findings and other studies have prompted concerns about the safety of acetaminophen use during pregnancy and have led scientists and healthcare professionals to issue statements.

The Role of Acetaminophen in Postnatal Developmental Disorders

While the focus has primarily been on the prenatal use of acetaminophen, studies have also explored the potential impact of postnatal exposure on neurodevelopmental disorders. Stephen T. Schultz and several colleagues published one of the first studies to suggest a link between acetaminophen and autism in 2008. The study surveyed parents of children with and without autism about their children’s use of acetaminophen or ibuprofen after receiving the measles-mumps-rubella (MMR) vaccination. The results indicated that acetaminophen use, but not ibuprofen use, was associated with an increased risk of autism.

A study published in the Journal of Internal Medical Research in 2017 suggests that acetaminophen may induce brain injuries associated with autism. The researchers emphasized the need to investigate the long-term effects of acetaminophen use in infants and the possibility that it may contribute to infantile autism.

Understanding the Mechanisms and Risks

While autism and ADHD are distinct conditions, they share many similarities, including their classification as neurodevelopmental disorders and their impact on the central nervous system. Autism primarily affects behavioral, social, and language skills and intellectual capabilities, while ADHD affects concentration, impulsivity, and the ability to sit still. Some children may be diagnosed with both conditions simultaneously.

The exact way acetaminophen may contribute to the development of autism and ADHD is not yet fully known. However, researchers have proposed several theories. One such theory suggests that acetaminophen may interfere with maternal hormones or cause neurotoxicity, affecting fetal brain development. Another theory points to the potential impact of acetaminophen on the body’s ability to process medications during early development. These theories underscore the need for further research to explain the specific risks and mechanisms involved.

Industry Response and Legal Implications

The potential link between acetaminophen and neurodevelopmental disorders has raised concerns about the actions of pharmaceutical companies and regulatory bodies. Critics argue that manufacturers of acetaminophen-containing products have failed to adequately warn pregnant women and parents of young children about the potential risks associated with its use. Lawsuits have been filed against major companies, alleging they neglected to provide proper warnings and disregarded the mounting evidence linking prenatal and postnatal acetaminophen use to autism and ADHD.

If your child has been diagnosed with autism or ADHD and was exposed to acetaminophen before or shortly after birth, you may be entitled to compensation. Contact Brock & Stout’s experienced team of personal injury lawyers for a free consultation to discuss your situation and potential legal options.