ABOUT ACETAMINOPHEN & AUTISM

Acetaminophen, often known as paracetamol, is a mild pain reliever that can be found in over-the-counter pain relievers like Tylenol®. It is usually thought to be safe to take while pregnant. In fact, acetaminophen is the most often used medication during pregnancy, with up to 65 percent of women in the United States and 50 percent of women in Europe using it during their pregnancies. During pregnancy, acetaminophen has been shown to cross into the placenta. This means if a pregnant woman takes acetaminophen, some of the medication enters the baby's system.

Some common over-the-counter brand name medicines containing acetaminophen are:

The widespread use of acetaminophen during pregnancy is due to the lack of evidence linking the medication to birth defects. However, increasing evidence suggests that taking acetaminophen during pregnancy may raise the child's risk of asthma, affect their immune system, have endocrine-disrupting effects, and cause behavioral and cognitive problems in these children. According to new research, mothers who took acetaminophen such as Tylenol® throughout their pregnancy were much more likely to have a kid with attention deficit hyperactivity disorder (ADHD) or autism.

In May 2021, a study conducted by researchers in Spain suggested using acetaminophen during pregnancy might increase the risk of having a child with autism spectrum disorder (ASD). The authors analyzed medical records involving more than 73,000 mother-child pairs across Europe, finding that kids exposed to acetaminophen in-utero were 19% more likely to be diagnosed with ASD than those who weren’t. While the findings are not definitive proof of a causal relationship between Tylenol® and autism, the authors called for more study of the issue. They also recommended that acetaminophen be used in pregnancy “only when necessary.”

Unfortunately, this isn’t the first study to associate the use of acetaminophen in pregnancy with an increased risk of Autism Spectrum Disorder (ASD). In 2018, researchers did a meta-analysis of seven studies involving 132,738 pairs of mothers and children. The analysis revealed a 20% higher risk of autism for children who had prolonged exposure to acetaminophen in the womb. In 2019, Johns Hopkins Bloomberg School of Public Health found that children whose cord blood samples contained the highest levels of acetaminophen were roughly three times more likely to be diagnosed with autism spectrum disorder later in childhood, compared to children with the lowest levels of acetaminophen in their cord blood.