Acetaminophen, the ingredient in Tylenol, is considered one of the safest drugs in the pharmacy. As a result, neither doctors nor patients worry about people taking acetaminophen during pregnancy. That may help explain why it is also one of the drugs pregnant people take most often. In fact, experts estimate that as many as half of pregnant women globally take this medication (also known as paracetamol outside the US). But is it as safe as people think?
Acetaminophen During Pregnancy Linked to Problems for Offspring:
A prospective cohort study, the First Baby Study, suggests that this pain reliever may not be entirely innocuous, however (PLOS One, Sept. 28, 2022). Researchers in Pennsylvania recruited 2,423 mother-child pairs to the cohort. Of them, 1,011 women had used acetaminophen for pain relief during their pregnancies.
When the children were three years old, investigators tested them. They used a validated 99-item Child Behavior Check List. Youngsters whose mothers had taken acetaminophen during pregnancy were more likely to have sleep problems and attention difficulties. Because the researchers had also collected information on psychosocial stress during pregnancy, they were able to make sure that did not account for the differences in children’s behavior. After they adjusted for stress and other possible confounders, the scientists found a statistically significant difference.
The researchers conclude:
“The present study found that in utero exposure to acetaminophen predicted sleep and attention problems in offspring at 3 years of age, both of which indicate problems with child self-regulation.”
In addition, they observe:
“these results are of public health concern and suggest caution in the use of medications containing acetaminophen during pregnancy.”
Previous Research on Behavioral Problems and Acetaminophen:
This study is not the first to find a connection between in utero exposure to acetaminophen and subsequent behavioral problems. A Danish study published in 2014 found that seven-year-olds whose mothers had taken acetaminophen during pregnancy were more likely to be diagnosed with attention-deficit hyperactivity disorder (JAMA Pediatrics, April 2014). Moreover, they were about 30 percent more likely to be taking prescribed medication for ADHD. This suggests that obstetricians and their patients may need to be more cautious about this common pain reliever.