Paracetamol (acetaminophen) is the most commonly used medicine in pregnancy, yet there are very few studies that have investigated the possible long-term consequences for the child. A new study from the Norwegian Institute of Public Health suggests that long-term use of paracetamol during pregnancy may increase the risk of adverse effects on child development.
The study uses data from the Norwegian Mother and Child Cohort Study to investigate the effect of paracetamol during pregnancy on psychomotor development, behaviour and temperament at 3 years of age. Almost 3000 sibling pairs were included in the study.
The study is a collaboration between the University of Oslo, the Norwegian Institute of Public Health and the Hospital for Sick Children in Toronto, Canada, and was published in the International Journal of Epidemiology 25th October 2013.
By comparing children who were exposed to paracetamol during pregnancy with unexposed siblings of the same sex, researchers could control for a variety of genetic and environmental factors, in addition to other important factors such as infections, fever, use of other medications, alcohol intake and smoking.
The study shows that children who had been exposed to paracetamol for more than 28 days of pregnancy had poorer gross motor skills, poor communication skills and more behavioural problems compared with unexposed siblings.
The same trend was seen with paracetamol taken for less than 28 days, but this was weaker.
To investigate whether the underlying illness could be the cause of the effect on the children, and not paracetamol itself, the researchers examined a different type of analgesic with another type of mechanism of action (ibuprofen). The researchers did not find any similar long-term effects after use of ibuprofen.
Need for more research