For 1-year-olds, spending two or more hours a day in front of screens - for television, video, mobile phones or other digital devices - may increase their chances of experiencing developmental delays in subsequent years, according to research published in the journal JAMA Pediatrics.
Based on data on 7,097 children, the study found that as screen time increased, so did the likelihood of developmental delays, primarily in communication and problem-solving skills.
For instance, children with up to two hours a day of screen time at age 1 were 61 percent more likely to have delayed development of communication skills by age 2 than were those who logged less than an hour a day of screen time. Risk was nearly five times greater for those with four or more hours a day of screen time.
Delays linked to the infants' amount of screen time also were found in their development of personal and social skills, as well as motor skills (arm, body, leg, hand and finger movement).
Children's health experts generally take a less-is-better stance on children's screen time, instead encouraging physical activity and personal, face-to-face interactions. Guidelines from the World Health Organization say "sedentary screen time" - such as watching TV or videos - is not recommended for infants and should be limited to no more than an hour a day for 2-year-olds.
In JAMA Pediatrics, the researchers noted that the data for their study did not differentiate between educational and other types of screen time.
"Because it is difficult to limit screen time in general in today's world of electronic devices," they wrote, "it may be beneficial to identify and limit the screen time aspects that are associated with developmental delays while taking advantage of the educational aspects."