Children born very prematurely are at risk for cognitive and behavioral problems linked to excess screen time, a Stanford Medicine-led study shows.
Research has linked excessive screen time to cognitive and behavioral problems in the general population of children, leading the American Academy of Pediatrics to recommend that parents limit their children's daily screen exposure to no more than two hours per day. But the connection between screen time and cognitive or behavioral challenges had not been previously studied in very premature kids.
In the study, which appeared recently in JAMA Pediatrics, more than two hours of daily screen time was correlated with lower IQ and a variety of behavioral issues in 6- and 7-year-old children who were born 12 to 16 weeks early, or around the fifth or sixth month of pregnancy. These children may be especially vulnerable to detrimental effects of excess screen time because of the neurological risks due to premature births, the research team said.
The finding is part of an effort to understand how to help high-risk preemies thrive years after they've left the hospital.
"It's clear that the environment of preemies' lives after they leave the neonatal intensive care unit is so critically important," said the study's senior author, neonatologist Susan Hintz, MD, who directs the Fetal and Pregnancy Health Program at Lucile Packard Children's Hospital Stanford. "We need to move our work into a different zone and ask how can we support these children and families as they transition home, and then help them in the years to come."
Following preemies as they grow up
For more than a decade, Hintz and her colleagues closely followed a group of hundreds of children who were born at least 12 weeks early, meaning they are "extremely preterm," and considered to be the highest-risk category. (Any birth more than three weeks before the due date is considered premature.) The study began as a way to evaluate how best to support preemies' breathing from the time of delivery, but has expanded to many other areas of their growth and development.
The newest work focused on links between the children's screen time and various cognitive and behavior outcomes, including measures of intelligence such as IQ and verbal comprehension; the children's ability to regulate behaviors and problem-solve, also known as executive function; social communication; and signs of attention deficit/hyperactivity disorder, including inattention, impulsivity and hyperactivity.
At the school-age follow up visit, when children in the study were 6 or 7 years old, families answered questions about the amount of time the children spent using screens, including watching TV and playing video games. (The data was collected before the global pandemic, meaning the effects of online learning were not part of the study.)
The children also had a battery of standardized assessments and exams at the visit. The researchers compared 238 children who spent more than two hours per day using a screen with 176 children who had less than two hours of daily screen time.
After adjusting for possible confounding factors, researchers saw that children in the high screen time group had IQ scores that were about 4 points lower. They also had worse scores on assessments of executive function and tests of inhibition (impulse control) and inattention.
Children with a TV or computer in their bedroom also had worse inhibition scores, as well as hyperactivity and impulsivity scores.
What matters to families?
While the findings suggest that parents of preemies may want to limit screen time as their kids grow up, the researchers said that there is more to learn about the relationship between the amount of time spent using a screen and how children fare. For one thing, the results can only point to an association between high screen time and some cognitive, executive function and behavioral challenges. They cannot say whether excess screen time causes these difficulties.
Because the data was collected before the pandemic, the study also could not evaluate the many new ways screens are now being used. For instance, said Hintz, video chats that help children engage with extended family, friends, and educational activities may have different associations with cognitive outcomes than watching TV.
"What we, as experts, need to focus on now is supporting these families in their goals for their children," Hintz said. "Families are not only focused on cognitive test scores; they care about everyday skills, such as children's relationships with family members and other kids. We tend to look narrowly through our little telescope of neurodevelopmental outcomes, and we need to start thinking more broadly with families about what they consider to be important."
Photo by Pat Charles