A new study published in the International Journal of Epidemiology claims that paracetamol (acetaminophen) use during pregnancy could correspond with children born with autism spectrum disorders, hyperactivity, or other attention-related symptoms.
This was the first study to report this seeming correlation between paracetamol and autism spectrum symptoms in children and it was also the first study to show different effects based on gender. While there was a 30 per cent rise in risk of attention-related symptoms to either gender, boys had an additional increase of 2 clinical symptoms of autism spectrum disorder specifically.
Scientists in Spain recruited just under 3,000 pregnant mothers and reevaluated them when their children were 1 and 5 years old. They found that at age 5, children who were exposed to paracetamol at some point during the first 32 weeks of pregnancy showed poor performance in tests of inattention, impulsivity and visual speed processing. Boys separately showed more autism specific symptoms when persistently exposed to paracetamol.
The researchers believe that as paracetamol acts as a cannabinoid receptor in the brain it helps receptors determine how neurons mature and connect with one another. When these receptors are affected in the developing fetus’s brain the paracetamol could alter neuron development processes, be directly toxic to the fetus’s brain, and/or also affect the immune system.
Researcher Claudia Avella-Garcia believes that the possible androgenic endocrine disruption caused by paracetamol in male brains could explain why boys are more likely to develop autism symptoms.
The conclusion is, as the nature of science goes, that further studies need to be conducted with more precise dosage measurements of the paracetamol and that further investigations need to look into the risks versus benefits of paracetamol use during pregnancy and early life. Just to be safe, it may be best to switch out that tylenol with a good massage during pregnancy until we have conclusive research on these hypotheses.