Prenatal acetaminophen exposure increases asthma risk in children

A secondary analysis of data also found a link between asthma development and ibuprofen use during pregnancy.

By Stephen Feller

OSLO, Norway, Feb. 10 (UPI) -- The drug paracetamol, commonly known as acetaminophen and sold as Tylenol, is associated the development of asthma in children if their mothers used it during pregnancy.

While researchers at the University of Oslo and University of Bristol said the study provides evidence of the link, they do not suggest changes to safety guidelines for paracetamol use among pregnant women.


A secondary analysis of data in the study also linked ibuprofen use by pregnant women to the development of asthma, researchers reported

Previous studies have shown that most pregnant women use acetaminophen for pain and fever, though it has been linked to lower testosterone in boys and attention deficit hyperactivity disorder.

"Uncovering potential adverse effects is of public health importance, as paracetamol is the most commonly used painkiller among pregnant women and infants," Maria Magnus, a researchers at the Norwegian Institute of Public Health, said in a press release.

For the study, published in the International Journal of Epidemiology, researchers analyzed data collected as part of the Norwegian Mother and Child Cohort Study on 53,169 children who had asthma by age 3, 25,394 who had it at 7 years old, and 45,607 children who received asthma medications at age 7 based on records from the Norwegian Prescription Database.


The data linked 5.7 percent of children who had asthma at age 3 and 5.1 percent who had it at age 7 with their mother's use of paracetamol during pregnancy, with the strongest associations if the mother used the drug more than once. Most commonly, the drug was used for some type of pain or fever, or influenza.

A secondary analysis also revealed a link between ibuprofen and asthma development by age 3, though not age 7.

The researchers said more work needs to be done to understand the link because it does not prove cause and effect.

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