Sleep problems "definitely start early, and (the researchers) showed that sleep problems persist over the early years," said Lisa Meltzer, a pediatric sleep specialist at National Jewish Health in Colorado, who was not involved in the study.

A team from Cincinnati Children's Hospital Medical Center in Ohio surveyed more than 250 mothers about their children's sleep behaviors when the kids were six, 12, 24 and 36 months old.

They found that one in 10 kids under age three has a sleep problem like nightmares, wakings, trouble falling asleep or an inability to sleep in the child's own bed.

This falls within the range of findings from other studies, which estimate that two to 33 percent of children experience sleep problems.

The research group found that the types of sleep problems shifted as the kids got older.

When the children were under two years old, the most common issues reported by moms who said their child had a sleep problem included troubles falling and staying asleep and not sleeping for long periods.

At three years old, the children more frequently had nightmares and restlessness.

If the children started out with no sleep problems, chances were good that none would develop, the study found.

Only six to eight out of every 100 children without any sleep issues developed a sleep problem between one survey period and the next.

However, 21 to 35 out of every 100 kids with a sleep problem continued to have issues later on.

"Oftentimes the message is, 'don't worry about Susie, this is typical and it will get better,'" said lead author Kelly Byars, a pediatric psychologist.

"Children don't outgrow sleep problems, and their data show this quite clearly," said Meltzer.

The study looked only at sleep complaints from the parents, and did not include children who have a sleep disorder diagnosed by a physician.

However, 12 to 20 percent of the kids snored multiple nights per week.

Byars's team found that parents typically didn't view snoring as a sleep concern, even though it is one of the main symptoms of a sleep disorder called obstructive sleep apnea.

"As a result, snoring could be completely overlooked during well-child visits, despite its known risk for" other health problems, Byars's team writes in its report, published in the journal Pediatrics.

Previous research shows that up to half of pediatricians don't ask about sleep problems, the researchers note, and parents may not know what is normal when it comes to babies' sleep, so they may not raise the issue.

While formal sleep disorders are considered more medically serious, Byars said sleep problems can have an effect on children's mood, attention and learning -- as well as on the sleep of parents.

Meltzer added that sleep is essential for kids' development.

"Sleep needs to be a priority for the entire family," Meltzer told Reuters Health. "Parents need to have consistent bedtimes, wake times, and consistent bedtime routines. Research has shown all those things are very important."

SOURCE: bit.ly/zLJs54 Pediatrics, online January 4, 2012.

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