THURSDAY, Oct. 28 (HealthDay News) -- Two-thirds of preschoolers in the United States are exposed to more than the maximum two hours per day of screen time from television, computers, video games and DVDs recommended by the American Academy of Pediatrics, a new study has found.

Researchers from Seattle Children's Research Institute and the University of Washington looked at the daily screen time of nearly 9,000 preschool-age children included in the national Early Childhood Longitudinal Study-Birth Cohort, an observational study of more than 10,000 children born in 2001.

On average, preschoolers were exposed to four hours of screen time each weekday, with 3.6 hours of exposure occurring at home. Those in home-based child care had a combined average of 5.6 hours of screen time at home and while at child care, with 87 percent exceeding the recommended two-hour limit, the investigators found.

Children who went to child care centers had an average of 3.2 hours each weekday at home and while at child care. The average for children who didn't go to child care was 4.4 hours per day.

Children in Head Start, a program for economically disadvantaged kids, had an average of 4.2 hours of screen time per weekday. But 98 percent of those 4.2 hours occurred at home, the study authors pointed out.

The study is scheduled for publication in an upcoming issue of the Journal of Pediatrics.

"A majority of children under the age of 5 years in the United States spend almost 40 hours a week with caregivers other than their parents, and it's important to understand what kind of screen-time exposure children are getting with these other caregivers," study author Dr. Pooja Tandon said in a news release from the journal's publisher.

Few states regulate the amount of screen time in licensed day-care settings, even though such rules would be helpful, she suggested.

"Parents can also play an important role by making sure all of their child's caregivers are aware of the AAP's advice regarding screen time," Tandon said.

More information

The American Academy of Pediatrics has more about children and media.