Prenatal prescription opioid exposure not linked to ASD

Children of mothers who take prescribed opiate painkillers during pregnancy may not have an increased likelihood of developing autism spectrum disorders (ASD) or attention-deficit/hyperactivity disorder (ADHD), according to a study by researchers in Sweden, the United Kingdom, and the United States.

Emma Cleary and colleagues analyzed rates of ASD in more than 1.2 million children born in Sweden between 2007 and 2018, as well as rates of ADHD in more than 900,000 children born between 2007 and 2015. They also determined maternal levels of exposure to opioid pain medications during pregnancy.

They report, “At the population level, we replicated previous findings showing that risk of neurodevelopmental disorders increases as the dose, duration, and number of prescriptions increases.” Two percent of the unexposed children had ASD by age 10, compared to 2.9% of children exposed to a low dose of opioids and 3.6% of children exposed to a high dose, with rates of ADHD following a similar pattern. However, they say, these associations “were substantially weakened or no longer present” when they controlled for a wide range of personal and familial factors, including genetic and environmental factors shared by siblings, and compared children whose mothers took prescribed opiates during pregnancy to children whose mothers took them before but not during pregnancy.

The researchers caution that their study population did not include mothers taking extremely high doses of opioids, or those taking the drugs for lengthy periods. However, Cleary says, “While this study is not able to rule out small increased risks with high amounts of exposure, the results suggest that there is not a causal effect of prescribed opioid analgesics on risk for two common neurodevelopmental disorders, providing more data to support decision-making.”

Citations

“Prescribed opioid analgesic use in pregnancy and risk of neurodevelopmental disorders in children: A retrospective study in Sweden,” Emma N. Cleary, Ayesha C. Sujan, Martin E. Rickert, Franziska Fischer, Tyra Lagerberg, Zheng Chang, Paul Lichtenstein, Patrick D. Quinn, Anna Sara Öberg, and Brian M. D’Onofrio, PLOS Medicine, September 16, 2025 (free online). Address: Emma Cleary, Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana 47405, [email protected].

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“Prescribed opioid pain medications during pregnancy likely aren’t associated with increased risk of autism, ADHD,” news release, PLOS, September 16, 2025.