New research indicates that autism can be reliably diagnosed in children months before pediatricians conduct routine screening for the developmental disorder.

A study looking at over 1,200 kids finds that an autism diagnosis made by a trained professional is accurate starting shortly after a child’s first birthday.

“Our findings suggest that an ASD diagnosis becomes stable starting at 14 months, and overall is more stable than other diagnoses, such as language or developmental delay,” said Karen Pierce of the University of California, San Diego who led the study.

The research published this week in the journal JAMA Pediatrics showed that the stability of an autism diagnosis was weakest when children were evaluated at ages 12 to 13 months. Among kids diagnosed at that age, only 50 percent were still on the spectrum when they were re-evaluated a few years later.

However, the autism label stuck in 79 percent of kids diagnosed at 14 months and 83 percent of those flagged at 16 months, the study found.

Currently, the American Academy of Pediatrics recommends that all children be screened for autism at 18 and 24 months.

The study included 1,269 children who were evaluated by a licensed psychologist between 12 and 36 months of age and who had at least one additional evaluation at a later date.

Overall, 84 percent of the children who were diagnosed with autism at their first psychologist visit retained the label when they were rechecked later.

Of those who were not still considered to be on the spectrum at a subsequent evaluation, only 2 percent were deemed typically developing. The rest had other developmental issues and were most commonly given the diagnosis of “ASD features,” a label used for young children who have signs of autism that are too weak to warrant an official diagnosis.

The Centers for Disease Control and Prevention estimates that 1 in 59 children have autism. Less than half of kids with the developmental disorder are diagnosed by age 4, according to the government agency.

“Once a toddler is identified as (having) ASD, there is an extremely low chance that he or she will test within typical levels at age three or four, so it’s imperative that we use every effective tool as early as we can to begin treating diagnosed children to the benefit of them and their families over the long-term,” Pierce said.