A new study, published in the International Journal of Epidemiology, has revealed that acetaminophen exposure may increase autism in and hyperactivity symptoms based upon prenatal exposure.
Approximately 2644 mother-child pairs were recruited in a birth cohort study during pregnancy; 88 per cent were evaluated when the child was one year old, and 79.9 per cent were evaluated when they were five years old. Mothers were asked about their use of paracetamol during pregnancy and the frequency of use was classified as never, sporadic, or persistent.
The study has determined an increase of 30% in the risk of attention function disorders and an increase of two clinical symptoms of autism spectrum symptoms in boys, compared to non-exposed children. The number of children exposed to any paracetamol at some point during the first 32 weeks of pregnancy were 43 per cent of children evaluated at age one and 41 per cent assessed at age five. Children exposed repeatedly revealed poorer performance on a computerized test measuring inattention, impulsivity and visual speed processing.
“Although we measured symptoms and not diagnoses, an increase in the number of symptoms that a child has, can affect him or her, even if they are not severe enough to warrant a clinical diagnosis of a neurodevelopmental disorder,” said lead author Claudia Avella-Garcia, researcher at CREAL. “The male brain may be more vulnerable to harmful influences during early life,” said Claudia Avella-Garcia. “Our differing gender results suggest that androgenic endocrine disruption, to which male brains could be more sensitive, may explain the association.”
“Paracetamol could be harmful to neurodevelopment for several reasons. First of all, it relieves pain by acting on cannabinoid receptors in the brain. Since these receptors normally help determine how neurons mature and connect with one another, paracetamol could alter these important processes”, said co-author Dr. Jordi Júlvez, also a researcher at CREAL. “It can also affect the development of the immune system, or be directly toxic to some fetuses that may not have the same capacity as an adult to metabolize this drug, or by creating oxidative stress.”
Claudia B. Avella-Garcia, Jordi Julvez, Joan Fortuny, Cristina Rebordosa, Raquel García-Esteban, Isolina Riaño Galán, Adonina Tardónf, Clara L. Rodríguez-Bernal, Carmen Iñiguez, Ainara Andiarena, Loreto Santa-Marina, Jordi Sunyer. Acetaminophen Use in Pregnancy and Neurodevelopment: Attention Function and Autism Spectrum Symptoms. International Journal of Epidemiology, 2016 DOI: 10.1093/ije/dyv