By KRISTA CONGER

It's 10:00 p.m. Do you know where your children are? If you tucked them in an hour ago, you might assume they're asleep. But, as the song goes, it ain't necessarily so. And if they're asleep now it doesn't mean they'll slumber until morning.

A poll released yesterday by the National Sleep Foundation indicates that children of all ages get less sleep than they should, and more than two out of three exhibit significant problems. The poll is the first-ever formal nationwide survey of children's sleep habits conducted by the National Sleep Foundation.

"Your children might be sleeping less than you think they are," said Lucile Packard Children's Hospital pediatric sleep specialist Rafael Pelayo, MD. "Just because they're in the bedroom doesn't mean they are asleep. Parents have to ask themselves ‘does my child wake up refreshed?' Do you wake up your children in the morning or do they wake you up?"

About 30 percent of school-age children have trouble waking up in the morning, according to the poll -- a good indication that they are not getting enough sleep. In every age group, from infants to grade-schoolers, the average amount of sleep was less than the recommended minimum. Despite these findings, most of the parents in the poll felt their children were getting approximately the right amount of sleep.

Rafael Pelayo is one of a handful of pediatric sleep researchers in the country. He and his colleagues conducted a nationwide survey that uncovered an alarming trend of bad sleep habits among U.S. children, from infancy onward. Photo: Grant Delin

Televisions in the bedroom and caffeinated drinks are at least partly to blame for the typical child's lack of z's. According to the poll, over one-quarter of children age 3 and older slurp at least one caffeinated beverage a day, shaving about 3.5 hours of badly needed sleep from their weekly total; and four out of every 10 school-age kids can thank a television in their bedroom for two fewer hours of snoozing per week. Lack of sleep can sometimes show up as poor performance at school, Pelayo noted.

"Kids who don't sleep well have trouble focusing in the daytime," said Pelayo, who is also an assistant professor of psychiatry and behavioral sciences at Stanford's medical school. Just because a child doesn't learn well doesn't automatically mean they have a learning disability. They could be sleep deprived."

Not surprisingly, the poll points out that the parents of poor sleepers are paying the price. Many lose significant chunks of shut-eye themselves while tending to their child at night. On average, parents of children sleep less than other adults; parents of infants suffer the most: the poll estimates they lose more than 200 hours of sleep during their child's first year.

Nearly three-quarters of these hapless parents would like to change something about their child's sleep habits, most often the time their children go to bed. Earlier bedtimes may pose difficulties for working parents, however, as they struggle to pick up children from daycare, race home to prepare dinner and maintain an appropriate bedtime routine that may include quiet playtime, a warm bath or reading aloud.

"Parents in general are getting home later, and since the adults are going to bed later, the children are too. This gets to be a real family issue," said Pelayo.

The earliest average bedtime for children in the poll was 8:25 p.m. for older toddlers (18 to 23 months old), with the youngest infants (0 to 2 months) clocking the latest average time at nearly 10 p.m. School-age children in the poll had an average bedtime of around 9 p.m.

Finally, more than half of those polled reported that their pediatrician had never asked them about their child's sleep even though some signs of potentially serious problems, such as consistent snoring, are easy to detect and most sleep problems are relatively easy to address.

So, what does it all mean? Although few of the children in the poll probably suffer from outright sleep disorders (such as apnea or restless leg syndrome), many exhibited other sleep problems, including night waking, difficulty falling asleep and reluctance to go to bed, and more than one-quarter of all the children seemed sleepy during the day. While some parents may write off these facts as the normal travails of childhood, again, it ain't necessarily so. Sleep difficulties can echo throughout a person's life.

"We don't think of these problems as disorders," says Pelayo, "but as something children will eventually outgrow. But now we're starting to see teens and adults with similar problems."

Tips for putting kids to bed

• Talk to your children about sleep just like you talk to them about nutrition and health. And, like nutrition, set a good example by making your own sleep a priority.

• Don't use sleep as a punishment by rewarding a child with a later bedtime or enforcing separate bedtimes for siblings. Choose a bedtime that allows your child to wake up refreshed each morning.

• Remove televisions from the bedroom and eliminate caffeine from your child's diet. Calculate the caffeine content of common beverages and foods at http://www.sleepfoundation.org/caffeine.cfm.

• Combat a fear of the dark by helping your child learn to sleep without a nightlight.

• If your child is a consistent snorer, or continues to have difficulty waking or remaining alert during the day, talk to your pediatrician. Although awareness about childhood sleep disorders is growing, some doctors neglect to look for sleep disorders in patients.

• Use learning tools like the National Institutes of Health Star Sleeper Web site (http://www.nhlbi.nih.gov/health/public/sleep/starslp) to emphasize the benefits of healthy sleep.

Stats to keep you up at night

• Nearly 70 percent of all children polled experience one or more sleep problems -- difficulty falling asleep or resisting bedtime, night wakenings, snoring or other breathing problems -- at least twice a week.

• Nearly half of all school-age children have a television in their bedroom, and 26 percent of children age 3 to 10 drink at least one caffeinated beverage daily.

• Children in all age groups averaged less sleep than the recommended minimum for their age.

• Thirty percent of all children awaken and need attention at least once a night. On average, parents are awakened twice a week and lose about 30 minutes of sleep each time.

• Parents of infants lose more than 200 hours of sleep during their child's first year.

• More than 25 percent of younger children (infant to age 5) seem sleepy during the day.

• Many parents don't know how much sleep their child needs nor how much they're actually getting.