Paracetamol (acetaminophen) is the most commonly used medicine in pregnancy but few studies have examined the effects of neurodevelopmental on the child.
In a new study from the Norwegian Institute of Public Health used data from the Norwegian Mother and Child Cohort Study;(all pregnant Norwegian women were eligible for recruitment into the prospective Norwegian Mother and Child Cohort Study) the effect of paracetamol during pregnancy on psychomotor development, behavior and temperament at 3 years of age.
The mothers were asked to report on their use of paracetamol at gestational weeks 17 and 30 and at 6 months postpartum.
The data used was on 48,631 children whose mothers returned the 3-year follow-up questionnaire by May 2011. Within this sample were 2,919 same-sex sibling pairs who were used to adjust for familial and genetic factors.
Researchers compared children who were exposed to paracetamol during pregnancy with unexposed siblings of the same sex and adjusting for a number of factors, including febrile illness, infections and co-medication use during pregnancy.
The sibling-control analysis revealed that children exposed to prenatal paracetamol for more than 28 days had poorer gross motor development, externalizing and internalizing behaviors (behaviors are both ways in which children and sometimes adults react to experiencing stress) and higher activity levels.
Children exposed prenatally to short-term use of paracetamol (1–27 days) also had poorer gross motor outcomes, but the effects were smaller than with long-term use.
Ibuprofen exposure was not associated with neurodevelopmental outcomes.
In their conclusion the researchers write “Children exposed to long-term use of paracetamol during pregnancy had substantially adverse developmental outcomes at 3 years of age.”
Professor Hedvig Nordeng, PhD, professor at the School of Pharmacy, University of Oslo, and is also affiliated as a researcher at the Division of Mental Health, Norwegian Institute of Public Health commented about the study “The results strengthen our concern that long-term use of paracetamol during pregnancy may have an adverse effect on child development, but that occasional use for short periods is probably not harmful to the fetus. Importantly, we cannot assume that there is a causal relationship between maternal use of paracetamol during pregnancy and adverse effects in children from an epidemiological study. Since this is the only study to show this, there is a need for further research to confirm or refute these results.”
“The findings support the advice of medical authorities; the first choice for pain is paracetamol, but one should be restrictive with all medicine use in pregnancy,” said Professor Nordeng.
This study is collaboration between the University of Oslo, the Norwegian Institute of Public Health and the Hospital for Sick Children in Toronto, Canada