Health and Human Services Secretary Robert F. Kennedy Jr. is expected to address a new Centers for Disease Control and Prevention report that found that 1 in 31 children born in 2014 were diagnosed with autism spectrum disorder.

Kennedy is scheduled to address the report Wednesday morning.

A previous CDC report indicated that among children born in 2012, 1 out of 36 had been identified with autism spectrum disorder by the time they turned 8 years old. Among children born in 1992, that proportion was 1 in 150, according to the Centers for Disease Control and Prevention.

Kennedy has said he wants answers as to why autism rates have gone up.

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“We've launched a massive testing and research effort that’s going to involve hundreds of scientists from around the world. By September, we will know what has caused the autism epidemic and we’ll be able to eliminate those exposures,” Kennedy said during a meeting of President Donald Trump's cabinet last week.

No one knows why autism rates have spiked in the past 25 years, but scientists think much of it is due to a broader definition of the disorder and better detection. They also say genetics and exposure to chemicals may play a role.

The CDC's report notes concern by the variability of autism detection rates. Officials believe there needs to be more uniformity in identifying autism spectrum disorder in order to provide proper treatment.

"Increased identification of autism, particularly among very young children and previously underidentified groups, underscores the increased demand and ongoing need for enhanced planning to provide equitable diagnostic, treatment, and support services for all children with ASD," the CDC's report says. "The substantial variability in ASD identification across sites suggests opportunities to identify and implement successful strategies and practices in communities to ensure all children with ASD reach their potential."

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