Prenatal Exposure To Acetaminophen Linked To Asthma Risk

A new study conducted by the Norwegian Institute of Public Health has confirmed a link between prenatal exposure to acetaminophen and an increased risk of developing asthma in early childhood. The researchers also found that the link was not associated with the reason for taking the drug.

Acetaminophen – also known as paracetamol – is widely used to treat a myriad of symptoms including fever, headache, back pain, arthritis pain and sciatica. The drug is most commonly sold under the trade name, Tylenol.

“Uncovering potential adverse effects is of public health importance, as paracetamol is the most commonly used painkiller among pregnant women and infants,” said Dr. Maria Magnus, primary author on the study. The research was published in the International Journal of Epidemiology.

While previous research demonstrated the link between acetaminophen consumption during pregnancy and infant asthma development, the current study was the first to show that the risk was independent of the reason the medication was taken. In order to demonstrate this finding, Magnus and her team analyzed data collected from 114,500 children and their mothers who were participating in the Norwegian Mother and Child Cohort Study.

The researchers studied women – some of which took acetaminophen – with several common conditions during pregnancy, and recorded whether their resulting children developed asthma between the ages of three and seven years old. The study investigators also set out to determine whether the link could be attributed to a specific reason for taking the drug – the most common of which are pain, influenza and fever.

At age three, Magnus and her colleagues found that 5.7 percent of the children had asthma; at age seven, that number was slightly lower at 5.1 percent. The results showed an independent link between asthma development at three and seven years of age, and prenatal or infant exposure to acetaminophen.

The most compelling link between asthma and acetaminophen exposure was identified when the expectant mother was taking the drug for more than one reason. This confirms the results of previous studies that have found no link between acetaminophen use outside of pregnancy, and shows that the increase in asthma risk is not due to other health factors aside from taking acetaminophen.

Despite the findings, the researchers stress that the results should not have any impact on the recommendations regarding acetaminophen use during pregnancy. The US Food and Drug Administration (FDA) recently reviewed the safety of pain medication use during pregnancy – which included acetaminophen – and maintained their advice that expectant mothers “should always consult with their health care professional before taking any prescription or over-the-counter (OTC) medicine.”