A survey released shows what millions of groggy parents already know: Many babies and toddlers do not get enough sleep.

Twenty-six percent of parents of children up to four years old said in a recent survey that their child gets less than enough sleep. The survey was commissioned by Pampers and conducted with the nonprofit National Sleep Foundation (NSF).

The older the child, the less likely he or she is to sleep 12 hours to 15 hours per day, the recommended minimum from the NSF and pediatric sleep experts, Pampers said.

Forty percent of parents and caregivers said that their child has a problem each or almost every day or night, including having a hard time falling asleep, waking up in the middle of the night or getting up too early in the morning.

The child's sleep patterns, of course, may lead to less sleep for parents. Of those surveyed, 71 percent said they get less sleep than they feel they need.

The results come from telephone interviews with a random sample of 1,003 parents or primary caregivers of children under four years old. The margin of error on the survey, conducted in September and October, is plus or minus 3.1 percent.

Details of the survey and tips for parents are will be released at an event in New York on Wednesday.

Pampers, the diaper and baby care brand, is part of Cincinnati-based Procter & Gamble Co.