A comprehensive study involving more than two million individuals has found no significant connection between the use of opioid painkillers during pregnancy and the subsequent diagnosis of autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD) in children. Conducted by researchers from Indiana University Bloomington, this research challenges earlier studies that suggested a potential link.
The researchers analyzed health records of over 1.2 million children born in Sweden between 2007 and 2018. They focused on the relationship between the dose and duration of opioid use during pregnancy and the risk of children being diagnosed with ASD or ADHD later in life. In addition, an additional cohort of 900,000 children born between 2007 and 2015 contributed data on ADHD diagnoses.
Among the findings, they observed that 2% of children born to mothers who did not use opioids received an autism diagnosis by age ten. In comparison, the rate increased slightly to 2.9% among those exposed to low doses of prescribed opioids in utero. For children exposed to higher doses, the rate was 3.9%. Similar trends were noted for ADHD diagnoses, although the study did not explore the effects of very high doses or prolonged use of pain medications.
The researchers highlighted that the overall evidence indicates minimal risk associated with opioid exposure during pregnancy concerning autism and ADHD. The study emphasizes the influence of various genetic and environmental factors that are more likely to contribute to these neurodevelopmental conditions than the use of painkillers.
“We wanted to conduct this study to help provide more information for pregnant individuals and their physicians who are trying to make complex decisions about how to best manage pain during pregnancy,” said Emma N. Cleary, a researcher at Indiana University Bloomington. Cleary pointed out that decisions regarding pain management are complicated by the lack of comprehensive data on the safety of opioids during pregnancy.
While the study could not completely rule out the possibility of small increased risks with high doses of exposure, the results suggest that prescribed opioid analgesics do not have a causal relationship with the risk of these common neurodevelopmental disorders. Cleary added, “These concerns include potential impacts on child neurodevelopment.”
Earlier studies had indicated a correlation between prenatal opioid use and elevated ADHD risk in children. For instance, a 2019 study noted that mothers prescribed opioid painkillers were 2.43 times more likely to have children diagnosed with autism. However, the researchers acknowledged that these findings were not definitive proof of causality.
The current study has led to a reassessment of prior conclusions. “While our analyses adjusted for several factors known to be associated with both ASD risk and opioid prescription, such as maternal age, smoking, and maternal psychiatric conditions, our estimates could be biased due to unmeasured confounders,” the researchers noted.
Additionally, over-the-counter (OTC) pain medication such as acetaminophen has also come under scrutiny for its potential association with autism and ADHD. Yet, comprehensive studies have often found no credible link between OTC medications and these neurodevelopmental issues.
Co-author Ayesha C. Sujan stated, “Our findings suggest that the observed associations between prenatal exposure to opioid analgesics and two major neurodevelopmental disorders are largely driven by factors leading up to opioid analgesic use rather than the opioid exposure itself.” Sujan urged the importance of providing pregnant individuals experiencing pain with psychosocial support and evidence-based pain management strategies.
The study concludes that neither autism nor ADHD can be attributed to a single cause. Instead, both conditions are recognized for their hereditary nature, with research suggesting a genetic basis ranging from 60% to 93%. Social and environmental influences are also critical, though they remain poorly understood.
The findings were published in the journal PLOS Medicine, contributing valuable insights to the ongoing discussion about pain management during pregnancy and its implications for child development.
