Sleep deprivation is normally thought of as an older person's problem, but a new study suggests even infants aren't getting enough Z's.

A study by the U.S.-based National Sleep Foundation has found almost 70 per cent of children in the households surveyed experienced sleep problems at least a few nights per week.

"Our new poll finds that many children are not sleeping enough and many experience sleep problems," Richard L. Gelula, the foundation chief executive officer, said in a statement.

"What is troublesome is that the problems start in infancy."

Those difficulties include trouble falling asleep, sleepwalking, snoring and breathing difficulties.

Caffeine is thought to be one of the reasons for sleep disruptions. The poll found that 26 per cent of children aged 3 or older drink at least one caffeinated beverage a day, including colas, chocolate drinks or iced tea. Those children slept a half-hour less each night than those who did not drink caffeine.

As well, children with televisions in their rooms went to sleep 20 minutes later than children without TVs, and slept on average 9.2 hours a night, compared to 9.6 hours a night -- "a loss of more than two hours of sleep a week", the foundation said. 

Here's how much sleep children should get in their age group, with the actual average from the survey in graphics:

• Infants: 14-15 (12.7)
• Toddlers: 12-14 (11.7)
• Pre-school: 11-13 (10.4)
• School-aged: 10-11 (9.5)

A bedtime routine is key, the experts say, and it should exclude television and include a bedtime story.

About 75 per cent of parents polled said they would change their children's sleep habits if they could -- they would be motivated by self-interest.

Parents and caregivers also reported getting less than optimal amounts of sleep, with the foundation reporting they lost an average of 200 hours of sleep per year and getting woken up four times per week due to their children's sleep problems.

The average reported by respondents was 6.8 hours, down from 7.0 in 2002. Most parents said they needed eight to nine hours of sleep to feel fully rested.

The survey contacted 1,473 adults who were either the primary caregiver or shared equally in the parenting of a child aged 10 or younger.

However, the sleep history of the children was based only on the memory of those polled.

Statistically, the survey's margin of error was 2.6 percentage points, although the foundation cautioned it could go as high as 6.8 percentage points for some categories, responses or totals.