Sleep: Ferber Speaks

Sleep schedules refer to the pattern of when people fall asleep, how long they sleep and the time they wake up. Each of us has an internal "clock" that determines how much sleep we need, as well as our disposition toward being an early riser or night owl. Aside from these individual differences, however, most people follow the same basic sleep patterns at each developmental stage.

Sometimes, a child needs to have her sleep schedule adjusted for her own sake or that of her family. Depending on the child's age, her schedule can be "coaxed" -by reducing stimulation at night, reducing or eliminating naps, or setting an earlier or later bedtime. To make a successful schedule shift, however, parents need to understand typical sleep patterns at various developmental stages.

• Babies - "Babies basically have no schedule," says Dr. Richard Ferber, a world-renowned sleep expert and director of the Center for Pediatric Sleep Disorders at Boston's Children's Hospital. "Variable periods of sleep and times of eating are randomly distributed throughout the 24-hour day."

Although a newborn's biological clock exists and functions, frequent disturbances-such as hunger, discomfort or external stimulation-interfere with this clock and, therefore, with establishing any sleep patterns this early in their development. Babies do gradually establish a schedule as they mature.

"At this stage, parents should avoid setting a rigid schedule of feeding and sleep for an infant," says Ferber. "Instead, establish some regularity and get feedback from the child as to what works and then reinforce that." For example, parents can set a naptime, but if the child never falls asleep until an hour later, delay naptime an hour and see if the child falls asleep more readily.

Although babies vary greatly, the sleep pattern settles considerably for most at about 3 months of age. To the relief of many parents, the majority of sleep is now generally at night. Daytime becomes more predictable with increasingly longer periods of wakefulness; naptime and eating begin following a schedule, too. This stabilization reflects brain maturation, and the baby's patterns of sleep are now similar to those that will remain for the rest of his life.

"While some infants may be sleeping through the night by 3 months, parents should neither expect nor push for it," Ferber cautions. Longer periods of sleep at night gradually increase as the baby matures. At 3 months, most babies are capable of sleeping at least five to six hours straight.