Tylenol use during pregnancy is linked to ADHD and behavior problems.

A study published in the journal Pediatrics finds that Tylenol (acetaminophen) taken by women during their pregnancy may raise the risk of ADHD (Attention Deficit Hyperactive Disorder) and similar disorders in their children up to 40%—and the risk is higher as use increases. The more acetaminophen the mother takes, the higher the risk in her child.

The study’s authors say it is plausible that the drug may interrupt fetal brain development by interfering with maternal hormones or through neurotoxicity. 

This isn’t the first study to note the connection between a mother’s Tylenol use and her child’s reaction to the toxic drug. Last year a troubling study showed that women taking acetaminophen during pregnancy increased the risk of their children having serious behavior problems at age 3 by an overwhelming 70%.

It is simply not worth the risk, to use acetaminophen. Every year, 78,000 people go to the emergency room from intentional or accidental acetaminophen overdose; 33,000 are hospitalized, and about 450 die.