Children exposed to opioids before birth face a higher risk of vision problems, attention difficulties and learning delays once they reach school age. That is the finding of a major systematic review published in the journal Addiction. The review was led by Dr Louise Marryat of the University of Glasgow. It brings together the clearest picture yet of what happens to children affected by prenatal opioid exposure once they move beyond infancy and into the classroom.

Speaking on the Addiction Audio podcast, Marryat explained that most existing evidence had focused on the earliest years of life. This left a gap in understanding what happens as these children grow older. Her team set out to examine any outcome in childhood. They covered health, education and social wellbeing rather than restricting the search to a single domain.

How Researchers Investigated Prenatal Opioid Exposure in School Age Children

The researchers screened almost 12,000 studies published between January 2015 and October 2025. They eventually narrowed the field down to 27 high quality articles covering 16 separate studies. Between them, these papers included more than 31,000 children who had been exposed to illicit opioids or medication for opioid use disorder in the womb. Researchers also compared this group against over five million children without that exposure. The included studies spanned ten high income countries. The largest clusters of research came from Norway, the United States and Australia.

Marryat noted that opioid exposure in pregnancy is often assumed to be rare. Yet data from Scotland suggests around one per cent of children each year are affected. She compared this figure to the prevalence of autism in the wider population.

Vision Problems Are the Clearest Sign of Prenatal Opioid Exposure

Of all the outcomes examined, poor vision emerged as the most consistent and robust finding linked to prenatal opioid exposure. Every one of the four studies that measured visual outcomes found a positive association. Exposed children showed markedly higher rates of squint, the involuntary eye movement known as nystagmus, and reduced visual acuity compared with their peers. One study found nystagmus in up to twenty per cent of exposed children, against fewer than two per cent among unexposed controls.

The review also found that children exposed to methadone tended to show worse visual outcomes than those exposed to buprenorphine. This pattern had already appeared at younger ages. Marryat pointed to Australia’s introduction of a twelve month vision check for children with a history of opioid exposure. She called it a practical response to the evidence, noting that many of these conditions improve if caught early.

Attention, Hyperactivity and Cognitive Delays

Beyond vision, the review found strong support for a link between early opioid exposure and difficulties with hyperactivity and inattention. This included a greater likelihood of a formal diagnosis of attention deficit hyperactivity disorder. Marryat cautioned that this relationship is complex. Hyperactivity has a strong genetic component and is itself linked to substance use, which makes it difficult to separate inherited risk from the direct effects of exposure in the womb.

A majority of the included studies, seven out of ten, also reported poorer cognitive outcomes among exposed children. These spanned verbal IQ, memory and rates of diagnosed developmental delay. This marks a notable shift from research into the preschool years, where cognitive differences were far less apparent. It suggests some effects of opioid exposure in pregnancy only become visible as children grow older.

Where the Evidence on Opioid Exposure in Pregnancy Runs Out

Despite the scale of the review, several major gaps remain. Almost none of the included research extended beyond the age of twelve, leaving adolescence almost entirely unexamined. No studies looked at outcomes such as a child’s own later substance use. Internalising difficulties such as anxiety or low mood were rarely measured at all. Findings on physical health, brain structure and brain function were also inconclusive, often drawn from very small samples.

Marryat attributed much of this gap to the recent development of the large linked datasets needed to follow children over long periods. Many cohorts simply have not yet aged into adolescence.

Why Early Identification Matters

The review’s authors stress that most children exposed to opioids before birth go on to do well. Even so, the consistent findings around vision and attention point to a clear opportunity for earlier support. The authors argue for extending routine developmental checks into school age rather than concentrating support solely around birth. They also call for better information for health visitors, teachers and families about what to look out for.

The findings reinforce a familiar message for anyone working in prevention. The consequences of opioid use during pregnancy do not end at birth. The earlier that vision, attention and learning difficulties linked to prenatal opioid exposure are identified, the better the chances of limiting their impact on a child’s life.

Source: dbrecoveryresources