0 to 5 Months
Newborns slip between the waking and sleeping states with little regard for day or night, typically feeding every two to four hours. Not until about 6 to 8 weeks does a more regular cycle begin to emerge, in which the baby sleeps more at night and stays awake more during the day. Making sure that your infant is exposed to sunlight during the day and kept in a darkened room at night establishes this pattern.
By 3 or 4 months, babies' sleep cycles begin to vaguely resemble those of adults, passing through cycles of active sleep (REM, or rapid eye movement) and deep sleep. Both stages are critical to development. "We know that the human growth hormone is released during deep sleep, so children require this stage of sleep to grow," notes Paul Saskin, clinical director of the Regional Center for Sleep Disorders at Sunrise Hospital, in Las Vegas. "And it is thought that REM is needed for learning and memory. Like a computer backing up its hard drive, the brain is organizing its filing system."
Newborns sleep about 16 to 17 hours a day. By 4 months, total sleep decreases to about 15 hours, the longest sleep period (which, with luck, occurs at night) stretches from about four to nine hours, and midmorning and midafternoon naps develop. At this point, parents can start reinforcing their child's biological rhythms by anticipating their baby's natural sleepiness, soothing him and putting him down to sleep before he gets overtired, says Dr. Weissbluth. "Helping your child fall asleep is like surfing: You want to catch the wave of drowsiness as it's rising, before your baby crashes into an overtired state," he explains. A good rule of thumb is to put your baby down to sleep every two hours.
As their baby approaches 6 months of age, "parents often ask, 'Why is my child still waking up three and four times a night?' " says Mark D. Widome, M.D., a professor of pediatrics at Pennsylvania State University College of Medicine, in Hershey. "Instead, they should be asking, 'Why does my child need my help to get back to sleep when he wakes up?'"
Indeed, researchers at McGill University, in Montreal, videotaped a group of infants and found that all woke up an average of four times a night. Many, however, did not call out but managed to soothe themselves back to sleep (the so-called good sleepers). Those described as problem sleepers tended to cry out and make their awakenings known.
"By 5 or 6 months, if a healthy child is waking up at night for feedings, it's a learned behavior," says Dr. Widome. "Don't be so quick to take her out of bed and feed her. If you do, you're not giving her ample opportunity to try to get back to sleep herself." Keep in mind, too, that the more often you put your baby to bed when she's still awake, the more practice she'll get soothing herself to sleep.