Women who take common pain killer acetaminophen (paracetamol) in pregnancy are at a greater risk of having a child with attention deficit hyperactivity disorder (ADHD), one of the most common neurobehavioral disorders of childhood, researchers reveal.
Children experiencing ADHD will have problems in paying attention, difficulty in controlling impulsive behaviors (acting without thinking about the consequences), and be prone to hyper activity. An early identification and treatment of the disorder is important, as it can have a negative impact on learning and academic development.
In a study published in JAMA Pediatrics, acetaminophen use in pregnancy was associated with 13 to 37 percent increased risk of ADHD or hyperkinetic disorder (a severe type of ADHD) in children.
For the study, researchers from UCLA in the US and University of Aarhus in Denmark selected 64,322 children and their mothers. All the participants were part of the Danish National Birth Cohort, between 1996 and 2002.
Researchers recorded maternal acetaminophen use during and after pregnancy. When the children turned seven, researchers interviewed parents about their children's hyperactivity, peer relationship, behavioural problems and emotional symptoms. At age 11, researchers analysed prevalence of hyperkinetic disorder among the children.
A significant number of mothers revealed using the fever-reducing drug after conceiving their child. Results showed a direct link between the drug use and the disorder. Prolonged use that lasted into the last stages of pregnancy showed stronger associations. Regular intake of the pain killer for more than 20 weeks nearly doubled the risk of ADHD in children.
Many studies in the past have shown the role of acetaminophen in disrupting hormones. Researchers said that the drug is powerful enough to cross placenta and thus influence foetal brain development.
Concerned with the findings, the authors urged women who are pregnant or planning pregnancy to totally avoid the medication. "We need further research to verify these findings, but if these results reflect causal associations, then acetaminophen should no longer be considered a 'safe' drug for use in pregnancy," senior author Dr. Jorn Olsen, from the University of Aarhus said in a news release.