Introduction –
Acetaminophen, commonly known as paracetamol, has long been perceived as the safest over-the-counter pain relief for consumption during pregnancy. However, recent research by the University of Illinois Urbana-Champaign (as part of the Illinois Kids Development Study) has questioned this assumption and shed light on concerns surrounding its potentially adverse neurodevelopmental effects on children.
While previous studies have produced similar findings, they have often been limited by measurement methods. By assessing acetaminophen use over several distinct periods, the recent study found that an increased consumption of acetaminophen during pregnancy may be associated with language development delays in children.
The Study –
Within the study, which spanned 7 years, women between 8 and 14 weeks pregnant, aged 18-40 years and residing close to the University of Illinois were recruited to take part. The women recorded the number of times they consumed acetaminophen during pregnancy and provided lifestyle-related, medication and pregnancy data through interviews.
About 70% of participants reported that they had used medications containing acetaminophen at least once while pregnant, with few reporting to have used other analgesics. Acetaminophen consumption was most common during the first trimester, and this was most often used for pain relief.
A total of 298 2-year-old children who had been followed prenatally and 254 who returned for further study at age 3 were subject to the following language-related tests:
- At 26.5-28.5 months (2 years old), parents of each child completed the MacArthur-Bates Communicative Development Inventories (CDI). The CDI measured expressive vocabulary, language complexity levels and the average length of the child’s longest three utterances, known as M3L. The vocabulary element asked parents to select words their child had used from a list of 680.
- At 36-38 months (3 years old), parents completed the Speech and Language Assessment Scale (SLAS). The SLAS was a short questionnaire that sought to assess assertiveness, articulation and responsiveness in children in comparison to their peers.
Conclusions Drawn –
Both the CDI and SLAS tests demonstrated that females had more advanced language in comparison to males, with the SLAS analysis not showing statistical significance in this regard.
The 26.5-28.5-month data suggested that higher acetaminophen consumption (particularly during second and third trimesters) was linked to reduced vocabulary size and M3L in children at that age, with each increase in consumption correlating to a decreased vocabulary size of almost two words in the 2-year-olds. Use of acetaminophen also showed a slight shortening of ‘mean length of utterances’.
The 36–38-month data suggested that higher levels of acetaminophen use during pregnancy within the second and third trimesters in particular could be linked with lower SLAS scores. This was consistent across both genders, but males showed significantly lower SLAS scores with heightened third-trimester exposure.
Conclusion –
This study is the first of its kind to use language development as a measure of the neurodevelopmental impact of acetaminophen exposure during pregnancy on children, and in several ways can be considered significant due to the comprehensive use of language development measurements and large cohort of participants.
Despite this, the study can be said to be limited in several ways. While the evidence certainly draws correlations between an increase in acetaminophen intake and poor language development, further research is needed to fully evidence and understand the correlation and to establish causality. Further to this, the possibility of self-reporting errors, lack of dosage information, potential inaccuracies and similarity of cohort are all limitations that should be considered in future studies.
