An epidemiological study has found a relationship between the symptoms of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD) detected among more than 70,000 boys and girls from six European cohorts and the paracetamol (acetaminophen) that their mothers indicated having taken during pregnancy.
The study, published in the European Journal of Epidemiology, was led by the Barcelona Institute for Global Health (ISGlobal), a center promoted by the ”la Caixa” Foundation. In total, 73,881 girls and boys were analyzed for whom data were available on prenatal and / or postnatal paracetamol exposure and at least one outcome on symptoms of ASD or ADHD, and main covariates.
Depending on the cohort, between 14% and 56% of the mothers of these children reported that they had taken paracetamol while they were pregnant. The results reveal that boys and girls who had been exposed to paracetamol before birth were more likely to subsequently develop symptoms of autism spectrum disorders and attention deficit disorders than those not exposed (19% and 21% more, respectively). “Our data is consistent with what previous work indicated. Likewise, we see that prenatal exposure to paracetamol affects boys and girls in a similar way, since we practically did not observe differences ”, explains Sílvia Alemany, researcher at ISGlobal and first author of the study.
For his part, Jordi Sunyer, ISGlobal researcher and last author of the study, highlights: “Our results address part of the weaknesses of the previous meta-analyzes. Taking into account all the evidence on the use of paracetamol and neurological development, we agree with the recommendations that indicate that, although paracetamol should not be suppressed in pregnant women or in childhood, it should be used only when necessary ”.
It is estimated that between 46% and 56% of pregnant women in developed countries resort to paracetamol at some point in pregnancy, which is considered the safest analgesic / antipyretic in this period and in childhood.
However, some studies have begun to link prenatal exposure to acetaminophen with poorer cognitive performance, more behavioral problems, ASD, and ADHD symptoms. These are studies criticized for their heterogeneity, so that on this occasion “an effort has been made to harmonize the way in which ADHD and ASD symptoms have been assessed or defined, as well as what it means to be exposed to paracetamol”, in Alemany’s words. “The sample is large”, he continues, “and jointly analyzes cohorts from different European countries (United Kingdom, Denmark, Netherlands, Italy, Greece and Spain).
In all the cohorts studied, the criterion has been the same, so that we have reduced the heterogeneity of criteria from which previous studies suffered ”. The study also analyzed postnatal infantile exposure to paracetamol, in this case no association was observed between paracetamol taken in childhood and symptoms of ASD. Despite this, the scientific team recommends continuing to investigate, given the heterogeneity of exposure in the various cohorts studied, which ranged between 6% and 92.8%.