A comprehensive study involving over two million individuals has found no significant link between the use of opioid painkillers during pregnancy and the prevalence of autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD). Conducted by researchers at Indiana University Bloomington, the study challenges earlier research that suggested a connection between prenatal opioid use and these neurodevelopmental disorders.
The research focused on the health records of more than 1.2 million children born in Sweden between 2007 and 2018. It examined the dose and duration of opioid use by mothers during pregnancy and assessed the children’s risk of later being diagnosed with ASD or ADHD. Among the findings, 2% of children born to mothers who did not use opioids received an autism diagnosis by the age of 10, compared to 2.9% in children exposed to low doses of prescribed painkillers. Among those exposed to higher doses, the autism rate increased to 3.9%.
For ADHD, a similar pattern emerged. While the study did not specifically analyze the effects of extremely high doses or prolonged use of pain medications, it indicated that prenatal exposure to opioids does not significantly heighten the risk of autism or ADHD. The researchers emphasized that a number of genetic and environmental factors are more likely to influence these conditions than opioid use during pregnancy.
Insights from the Research Team
“We aimed to provide more information for pregnant individuals and their healthcare providers on managing pain during pregnancy,” said Emma N. Cleary, a researcher at Indiana University Bloomington. She noted that decisions surrounding pain management are particularly challenging due to insufficient data on the safety of opioid medications during pregnancy.
While Cleary acknowledged that this study could not completely exclude small increased risks associated with high exposure levels, the results suggest no causal relationship between prescribed opioid analgesics and these two common neurodevelopmental disorders.
Earlier studies had suggested a connection between prenatal opioid use and an increased risk of ADHD. A 2019 study indicated that mothers prescribed opioid painkillers were 2.43 times more likely to have children diagnosed with autism. However, the researchers cautioned that these findings did not establish a direct link, as the increased risk could be influenced by various factors associated with both opioid prescriptions and ASD.
Broader Implications and Future Research
“While we adjusted for several known factors related to ASD risk and opioid prescriptions, such as maternal age, smoking, and psychiatric conditions, our estimates may still be biased due to unmeasured confounders,” the authors explained.
The study also noted that over-the-counter (OTC) pain medications like acetaminophen have been scrutinized for potential links to autism and ADHD, although comprehensive studies have often found no credible associations.
The findings underscore the importance of addressing the factors leading to opioid use rather than the exposure itself. “Our results highlight the need for pregnant individuals experiencing pain to receive psychosocial support and evidence-based pain management strategies,” said co-author Ayesha C. Sujan.
As research continues, it is clear that neither autism nor ADHD can be attributed to a single cause. Both conditions demonstrate a high heritability rate, with studies suggesting a genetic basis of between 60% and 93%. Social and environmental influences also remain poorly understood.
“Pregnant individuals and their healthcare providers must balance the need to manage pain with concerns about potential consequences of opioid exposure on neurodevelopment,” Cleary added.
This pivotal research is published in the journal PLOS Medicine and provides valuable insights for both medical professionals and expectant mothers navigating complex decisions during pregnancy.
