The consumption of medications during pregnancy can affect the development of the fetus and have serious consequences on the long-term health of the child. Paracetamol – also known as acetaminophen – is an analgesic and antipyretic, whose use by pregnant women has been questioned due to its possible risks, and a study published in 2021 in Nature Reviews Endocrinology indicated that taking this drug during pregnancy could increase the risk of autism, ADHD and intellectual disability.
Now, however, a new study by researchers at Drexel’s Dornsife School of Public Health and Sweden’s Karolinska Institute that is considered the largest to date on the topic has found no evidence to support a causal link between the use of paracetamol during pregnancy and an increased risk of autism, ADHD and intellectual disability in children.
Scientists analyzed data from more than 2.4 million children born in Sweden between 1995. During the study’s follow-up of up to 26 years they detected a slight increase in the risk of autism, ADHD and intellectual disability in the general population. However, when siblings exposed and not exposed to acetaminophen in utero were compared, the researchers found no differences.
Since siblings share much of their genetic background as well as similar exposures to many of the same environmental factors during development, comparing siblings helps control for these shared factors that would otherwise be difficult to measure in epidemiological studies. noted the authors, who have published their findings in the Journal of the American Medical Association (JAMA).
“Paracetamol users differ from non-users in several ways and standard statistical analyzes without sibling control cannot control for all differences,” said co-senior author Brian Lee, associate professor at the Dornsife School of Public Health in New York. Drexel, a member of the AJ Drexel Autism Institute, and a research affiliate at the Karolinska Institute. “Sibling comparisons allow us to control for family characteristics that could explain an apparent relationship between acetaminophen use during pregnancy and the risk of neurodevelopmental diseases.”
Factors that influence neurodevelopmental disorders
Using data from Sweden’s national health and drug prescription registries, researchers collected data on medication use during pregnancy for births from 1995 to 2019. Only about 7.5% of the study sample – 185,909 children – were exposed to paracetamol during pregnancy. In previous studies, acetaminophen use during pregnancy varied considerably depending on the study setting; a study in Denmark reported 6.2% use, while a study in the US reported 10 times higher use.
Previous studies suggested that many pregnant women who could benefit from acetaminophen do not take it for fear of side effects, such as a 2019 study that surveyed 850 Swedish pregnant women, in which more than 60% considered using the medication during early pregnancy as “probably harmful” or “harmful.”
They recommend that all pregnant women follow their doctor’s advice on whether paracetamol is safe for them and their future children.
“The findings of this study may be welcome news for pregnant women who use acetaminophen as an option to control pain or fever, as there are few safe alternatives for relief available,” said co-senior author Renee M. Gardner of the Karolinska Institute in Sweden. “We hope our results provide peace of mind to expectant mothers when faced with the sometimes complicated decision of whether to take these medications during pregnancy when they experience pain or fever.”
The study authors say the statistically increased risk of neurodevelopmental disorders in children exposed to acetaminophen in utero is likely due to other factors, but they recommend that all pregnant women follow their doctor’s guidance about whether acetaminophen is safe for them. and their future children. “Our study and others suggest that there are many different health and family factors that are associated with both acetaminophen use and neurodevelopmental disorders,” Lee said. “Genetics probably plays a role, but more work is crucial to elucidate this mechanism.”
In 2015, the U.S. Food and Drug Administration said that studies on over-the-counter pain medications “are too limited to make any recommendations,” but noted that “severe, persistent pain that is not effectively treated during pregnancy can result in depression, anxiety and high blood pressure in the mother.”
Although Drexel and Karolinska’s study used data on paracetamol prescribed by doctors and pregnant women’s reports to their midwives during prenatal care and may not include all over-the-counter use in all patients, the findings represent data from a large representative sample. and control many other factors that may be linked to neurodevelopmental disorders.
“Paracetamol use during pregnancy was not associated with the risk of autism, ADHD or intellectual disability in children in the sibling control analysis. This suggests that the associations observed in other models may have been attributable to familial confounding factors,” the authors conclude in their article.
