Study Links Acetaminophen In Pregnancy To ADHD, But Experts Question Results

Acetaminophen has long been the pain reliever of choice for pregnant woman in the United States. For fever and pain during pregnancy, doctors often recommend acetaminophen. It is believed that 65% to 70% of pregnant women in the US use acetaminophen. However, a new study points out that long-term use of acetaminophen during pregnancy is not healthy. According to the study published in the journal Pediatrics, long-term use of acetaminophen during pregnancy is associated with twice the risk of attention-deficit hyperactivity disorder in children. Let’s get to the details.

What Is Acetaminophen?

Also known as paracetamol, acetaminophen is the active ingredient in Tylenol and hundreds of over-the-counter and prescription medicines. It is often used to treat pain and fever. It is also combined with other active ingredients in medicines that treat allergy, cough, colds, and flu.


Use Of Acetaminophen And ADHD

The data for the research was drawn from the Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Health. The cohort includes 114744 children born between 1999 and 2009, 95242 mothers, and 75217 fathers from all over Norway. Pregnant women were invited to participate after routine ultrasound examinations around week 18 of their pregnancies. Questionnaires that asked about their medication use were given to them during the pregnancy period at multiple points.

Among the women who participated in the study, nearly 47% used acetaminophen during their pregnancies. Almost 27% used it in one trimester, 16% in two trimesters and less than 4% in all three. And the findings concluded that using acetaminophen for a long-term during pregnancy gave a 220% increase in risk for ADHD in the child. Wondering what constitutes long term? As per the study, long-term refers to 29 days or more. Offsprings prenatally exposed to acetaminophen had an increased unadjusted hazard rate of ADHD of 17%, 39%, and 46% after 1, 2, and 3 trimesters of exposure, respectively.


Children with ADHD, which is a neurodevelopmental disorder, may have trouble paying attention or controlling impulsive behaviors. Sometimes they will be overly active.

The short-term use of acetaminophen is not found to be harmful. Even the researchers suggest that pregnant women who need treatment for fever and pain should not hesitate from acetaminophen use for a short-term. The use of acetaminophen by pregnant women for less than seven days was associated with a decreased risk of ADHD in kids. However, they don’t encourage long-term use. The best option is to consult their doctor.


What Happen If Fathers Take Acetaminophen

The study also considered the cases where fathers took acetaminophen before conception. And the study concluded that it increases the risk of ADHD in the offsprings. But, there is a lack of clarity here. The risk might be because of change in sperm that happened with the use of the drug. Or it might be because of the underlying condition that forced the dad-to-be to take the medicine. However, the researchers pointed out the lack of data to make any recommendations for fathers.

Limitations Of The Study

The research could not establish a cause-effect relationship between the drug and ADHD. But, researchers believe further study on the topic would reveal more. However, a few experts point the flaws in the research. They disagree the way in which a diagnosis of ADHD is assessed. Moreover, they point out the failure in measuring the amount of acetaminophen. The patients self-reported the number of days they used acetaminophen in the survey.


Experts also point out that acetaminophen is usually taken for a short-term. If someone has to take it for a long-term, then she may have some underlying medical condition. And chances are high that this medical condition may be associated with ADHD in the children.