CHICAGO — The nation’s largest pediatricians group is relaxing its stance against swimming lessons for children younger than 4.

In the past, the American Academy of Pediatrics has said swim classes might give toddlers and parents a false sense of security. Now the group says it’s fine to enroll children as young as 1.

A few small studies suggest toddlers may be less likely to drown if they’ve had swim lessons. The doctors aren’t recommending lessons for every young child. Some parents may feel their little ones aren’t ready and that’s OK.

Parents should choose classes that emphasize water safety and require a parent or other adult to be in the water with the child, said Connie Harvey, who heads aquatics development for the American Red Cross and wasn’t involved in the doctors’ policy update.

Classes should have at least one instructor for every 10 students, she said.

The updated policy, released online today by the journal Pediatrics, also recommends fences around all pools, even popular inflatable ones. Kids can drown by leaning over the soft sides and falling in.

And the group warns that children can drown when their hair or hands get sucked into the drains of pools or spas without drain covers or proper filter-pump equipment.

The rate of childhood drowning deaths has declined in recent years. About 1,100 children drowned in the U.S. in 2006.

Parents know they should be vigilant while children swim, but trouble can occur in an instant of inattention, said Dr. Jeffrey Weiss of Phoenix Children’s Hospital and lead author of the policy.

“It’s not a lack of supervision, it’s a lapse of supervision,” Weiss said.