One the most difficult aspects of autism is the fact many parents aren't aware their child has the disorder until they get a little older. New research suggests warnings signs can be spotted before a child hits 12 months.

Among the more common "red flags" cited in the study is an unusually high rate of repetitive behaviors, such as flapping their hands or arms, rocking back and forth, or focusing obsessively on one toy.

The study, conducted by University of North Carolina at Chapel Hill, included 184 children at high risk of autism as well as 59 children that were considered to be at average risk of the disorder. When the children were 12 months and 24 months old, their parents completed a standard questionnaire on repetitive behaviors.

What the study found was that, overall, 42 of the high-risk children were diagnosed with autism by the age of 2, and that those children had shown many more repetitive behaviors at the age of 12 months, citing an average of four to eight different types of repetitive behavior patterns. The researchers pointed out that one or two different types of repetitive behavior patterns were present for the kids without an autism disorder.

However, what may make the findings confusing for many parents is the fact that researchers did conclude that some amount of repetitive behavior is normal for babies.

While that is true, "in typically developing children, that usually peaks around the age of 6 months," explained lead researcher Jason Wolff, an assistant professor of psychiatry at the University of North Carolina at Chapel Hill. "In children who go on to develop autism, repetitive behavior is still highly prevalent, or even increasing, at the age of 12 months."

While those in the field of studying autism are encouraged by the study's findings, they all agree the results should be considered preliminary.

Autism rates continue to rise in the United States. A recent survey conducted by the Centers for Disease Control and Prevention claims one in 68 U.S. children has an autism spectrum disorder, a 30 percent increase from a similar survey two years ago.