Seventy percent of children with autism who have a history of severe language delays are speaking by the time they are 8 years old, according to a study being published Monday in Pediatrics, the journal of the American Academy of Pediatrics. The study, by researchers at the Kennedy Krieger Institute’s Center for Autism and Related Disorders, shows that far more children with autism than previously thought are making significant gains in speech and language after they enter elementary school.

“This hits that it is in fact a delay, it’s not a deficiency,” said Ericka L. Wodka, the lead author of the study and a neuropsychologist at Kennedy Krieger in Baltimore. “It’s not something that’s not achievable for these children, it’s just a delay.”

This is the first study of this size to look specifically at children with severe language delays and how a child’s intellectual and social abilities affected acquisition of language, Wodka said.

The Kennedy Krieger study looked at 535 children ages 8 or older who had not put words together in meaningful phrases by the time they were 4 years old. Of the 535 participants, 119 children had mastered speaking in phrases by their eighth birthday, and 253 were speaking fluently. One hundred sixty-three children never gained phrase or fluent speech.

The study showed that children with typical nonverbal intelligence scores and those who were interested in engaging in social interactions were most likely to make significant gains in language. To determine a child’s level of interest in social interaction, Wodka said researchers asked parents if their child pointed to objects of interest, offered to share things and used facial expressions.

“When you’re thinking about treatment, you really need to be working on the social aspects of communication,” Wodka said. “That’s really key to the language deficits we see in kids with autism. It’s not a pure speech impairment. It’s an impairment in social communication.”

Wodka said parents should be encouraged that with intensive and appropriate speech and language therapy, children with autism who have average intelligence can make great gains through the first few years of elementary school.

“If you think about traditional brain development and language, you have a critical period in toddlerhood when the brain is so ready to develop language,” Wodka said. “As you get out of toddlerhood and into the school-age years, there’s still continued room for development. It’s not the same brain plasticity that you had in toddlerhood, but the door’s not shut.”