(HealthDay)—Screen time is significantly associated with autism spectrum disorder among boys at age 3 years, according to a study published online Jan. 31 in JAMA Pediatrics.

Megumi Kushima, from the University of Yamanashi in Chuo, Japan, and colleagues examined the association between in infancy and development of at age 3 years using data from 84,030 mother-child dyads in a large birth cohort in Japan. Screen time was measured at age 1 year.

The researchers found that at age 3 years, the prevalence of children with disorder was 392 per 100,000 (0.4 percent) and boys were three times more likely than girls to be diagnosed with autism spectrum disorder. Compared with no screen time, among boys, the adjusted odds ratios were 1.38 (95 percent confidence interval [CI], 0.71 to 2.69; P = 0.35) for less than one hour; 2.16 (95 percent CI, 1.13 to 4.14; P = 0.02) for one hour to less than two hours; 3.48 (95 percent CI, 1.83 to 6.65; P < 0.001) for two hours to less than four hours; and 3.02 (95 percent CI, 1.44 to 6.34; P = 0.04) for more than four hours. No association was seen between autism spectrum disorder and screen time among girls.

"The main finding of this study was that, among boys, a statistically significant association was found between longer screen at 1 year of age and autism spectrum disorder at 3 years of age, irrespective of potential maternal maltreatment or predisposition to autism spectrum disorder at 1 year of age," the authors write.