High doses of paracetamol during pregnancy have been linked to reduced vocabulary in children
A study by US researchers found that taking more paracetamol in the second and third trimesters was associated with a reduction in vocabulary and rate of speech between 26.5 and 28.5 months of age, and the association was stronger in boys. However, the study has methodological limitations: the researchers do not report the statistical significance of the associations found, nor do they separate the effects of paracetamol from those of infection, for which it may have been used. The work is published in the journal Pediatric Research.
Most clinical guidelines prescribe that pregnant women should take paracetamol as first-line treatment for pain and fever. Various studies show that 50-65 percent of pregnant women in North America and Europe reported taking paracetamol at least once during pregnancy. However, not much data exists on the safety of paracetamol during pregnancy, with the drug known to penetrate the placenta.
Epidemiological studies show that prenatal exposure to paracetamol is associated with developmental delays in motor, attention, and behavioral problems. However, there are virtually no studies examining the effects of paracetamol ingestion during pregnancy on speech development in children.
Megan L. Woodbury and colleagues at Northeastern University conducted a study of 532 mother-child pairs. 298 children aged 26.5-28.5 months were tested for speech development, and 254 children were tested at 36-38 months of age. The mothers recorded the amount of paracetamol taken throughout the pregnancy - about every six weeks.
It was found that increased paracetamol intake during pregnancy was associated with reduced vocabulary size, reduced fluency and reduced ability to pronounce complex words. This association was particularly pronounced with more frequent intake of the drug in the second and third trimesters of pregnancy. Meanwhile, boys whose mothers took a lot of paracetamol in the third trimester of pregnancy showed a decline in verbal fluency scores below the 25th percentile.
Researchers also observed similar associations in children at 36-38 months of age. Increased paracetamol consumption in the second and third trimesters was associated with reduced speech development test scores. Boys were also more severely affected at this age.
Although this study shows some association between paracetamol intake and impaired speech development in children at 2-3 years of age, its methodology does not allow this result to be considered relevant. First, the researchers do not cite the amount of paracetamol taken by mothers that could be associated with specific speech impairments. Second, the researchers do not cite the statistical significance of these associations. In addition, a common problem with such studies is the difficulty of separating the effect of paracetamol from the effect of the infection for which it was used.
A wide variety of factors can affect the neuropsychiatric development of children. For example, Japanese scientists have shown that children who were between three and five years old during the covida pandemic lagged behind in neuropsychiatric development by almost five months compared with their peers who were growing up in normal times.