An influential U.S. health panel said on Monday it needs more evidence to support universal screening for autism in young children who show no developmental problems, in a departure from recommendations issued by other medical groups.

The proposed guideline, from the U.S. Preventive Services Task Force, an independent, government-backed panel that recommends whether to adopt screening tests for various conditions, applies to children aged 18 to 30 months who show no signs of an autism spectrum disorder (ASD).

It represents the first time the task force has looked at autism screening, and comes as ASD diagnoses rise in the United States. About one in 68 U.S. children has an autism spectrum disorder, which can create difficulties with social interaction, communication and other aspects of everyday life, according to the Centers for Disease Control and Prevention.

Other organizations promote some level of ASD screening during early childhood, including the American Academy of Pediatrics (AAP), which recommends ongoing surveillance and screening at 18 and 24 months regardless of whether a child show signs of the disorder.

"We want to make sure this recommendation is not misunderstood," Dr. David Grossman, vice chairman of the task force, said in an interview. "Children who are exhibiting signs and symptoms should be referred and tested."

The task force review, which began in 2013, found significant research gaps regarding the benefits and harms of screening all children for ASD, said Grossman, who is also a pediatrician in Seattle.

“We need more evidence and we think that evidence is achievable," Grossman said.

The task force said, for example, it needs more research on the outcomes of children who are diagnosed through screening even though they do not have signs or symptoms of ASD.

The task force did find evidence to support the accuracy of the tools used to screen children, notably the Modified Checklist for Autism in Toddlers (M-CHAT).

Parents answer a series of questions about their children such as communication skills, attention and movements in the M-CHAT. Based on those results, a closer examination may be required to diagnose ASD.

Under the AAP recommendation, healthcare providers would regularly watch for signs of ASD, and screen a child with a tool such as M-CHAT at ages 18 and 24 months.

“That combination approach has been shown to be effective at identifying kids early,” said Dr. Susan Levy, chair of the AAP's autism subcommittee. Levy was not involved in crafting the proposed guideline.

Levy, who is a developmental and behavioral pediatrician at the Children’s Hospitals of Philadelphia, said her concern is that the task force’s statement will lead people to question the benefit of screening.

Early identification allows for early intervention, which is known to result in better outcomes for children, she said.

Parents of toddlers should tell their pediatricians about poor eye contact, problems with social connections, responsiveness and interest in peers.

“Just having the family say 'I’m concerned about my child’s development' is enough,” she said.

The public can comment on the task force's proposal until Aug. 31 on its website: bit.ly/1N4Ea5j