For the second time in less than a month, researchers are reporting a potential breakthrough in their ability to spot autism signs in children who are less than a year old.

A study published Monday suggests that by examining differences in the amount of cerebrospinal fluid around babies’ brains, it’s possible to predict with nearly 70 percent accuracy which children will develop autism.

“The (cerebrospinal fluid) is easy to see on standard MRIs and points to a potential biomarker of autism before symptoms appear years later,” said Joseph Piven, director of the Carolina Institute for Developmental Disabilities and an author of the study published in the journal Biological Psychiatry.

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Magnetic resonance imaging, or MRIs, conducted on 343 infants at ages 6, 12 and 24 months were examined for the study. Of the children, 221 were considered to be at higher risk for autism because they had older siblings with the developmental disorder while the others had no family history.

Children who were later diagnosed with autism had a “significantly greater” volume of cerebrospinal fluid at 6 months as compared to those who were typically developing, the study found. Moreover, the amount of cerebrospinal fluid also served as an indicator of the severity of a child’s autism with more fluid associated with weaker gross motor skills.

“Normally, autism is diagnosed when the child is 2 or 3 years old and beginning to show behavioral symptoms; there are currently no early biological markers,” said David Amaral, director of research at the University of California, Davis MIND Institute and an author on the paper. “That there’s an alteration in the distribution of cerebrospinal fluid that we can see on MRIs as early as 6 months, is a major finding.”

The research is a follow-up on a smaller study four years ago with similar findings. While further examination is still needed, those behind the work said that cerebrospinal fluid may one day be used to assess a child’s risk for autism and other neurological issues.

“Prior to our 2013 study, radiologists would often call this ‘benign extra-axial fluid,’ meaning it had no clinical significance,” Amaral said. “This finding may alert radiologists and neurologists to the possible negative consequences of increased subarachnoid (cerebrospinal fluid).”

The latest findings come just weeks after another paper was published also pointing to a method to predict autism in babies by looking at MRIs. In that study, researchers observed far more rapid growth of the brain’s surface area in children with autism.