A scientific study is reigniting the debate over the safety of using paracetamol (also known as Tylenol) during pregnancy, particularly regarding claims linking it to autism spectrum disorder in children.
A large study that lasted nearly two decades in Hong Kong concluded that there is no evidence that taking paracetamol during pregnancy increases the risk of children developing autism spectrum disorder or attention deficit hyperactivity disorder.
In this study, researchers analyzed data from over 708,020 mother-child pairs, using a statistical method known as "sibling matching." This method compares children from the same family, one of whom was exposed to the drug during pregnancy while the other was not. This allows for more precise isolation of the drug's effects while minimizing the influence of shared genetic and environmental factors.
The results showed that the use of paracetamol during pregnancy was not associated with an increased risk of developing either disorder, either in terms of dose or timing of use during pregnancy, as no differences were recorded between use in the early or late stages of pregnancy.
This research comes at a time when the debate surrounding the drug has resurfaced, following claims linking it to an increased risk of autism. These claims are based on previous observational studies that suggested a possible association but did not establish a clear causal relationship.
International health authorities, including the World Health Organization and regulatory bodies in the United Kingdom, confirm that paracetamol remains a safe option during pregnancy when used according to medical guidelines.
In contrast, previous studies indicate that some of the associations that appeared in traditional research disappear when more precise analytical methods are used, such as comparing siblings, suggesting that family or genetic factors may be behind these results rather than the drug itself.
In this study, the researchers also monitored the use of the drug through official medical records that spanned many years, in some cases up to 23 years, while tracking the children's diagnoses later.
The team also conducted a further analysis involving mothers who used paracetamol before pregnancy or after childbirth, and found similar results in terms of a slight increase in risk, reinforcing the hypothesis that shared family factors are the most likely factor behind these associations.
The researchers conclude their study by emphasizing that paracetamol remains an important treatment option for relieving pain and fever during pregnancy, while warning that avoiding its use unnecessarily may lead to leaving fever untreated or resorting to alternatives that may be more dangerous for the fetus, such as some anti-inflammatories or opioids.
The results were published in the journal JAMA Internal Medicine.
