Sleep in Infants and Young Children: Part One: Normal Sleep

Katherine Finn Davis RN, MSN, CPNP; Kathy P. Parker PhD, RN, FAAN; Gary L. Montgomery MD


J Pediatr Health Care. 2004;18(2) 

In This Article

Measurement of Sleep and Sleep in the Newborn

The standards for the measurement of sleep differ according to age. The gold standards for scoring sleep stages in the newborn includes sleep behaviors, respiratory rates, eye movements, EEG, and muscle tone (Anders et al., 1995). In the older infant and children, polysomnography can be utilized and is similar to recordings in adults. Polysomnography is the concurrent and continuous recording of physiologic variables during the sleep period. Sleep stage scoring is based on three basic measurements: the EEG, electrooculogram (EOG), and electromyogram (EMG). During polysomnography, the heart rate, respiratory movements, airflow, and oxygen saturation are monitored, and limb movements are recorded (Carskadon & Rechtschaffen, 2000). Most overnight studies are performed in a sleep laboratory.

The circadian and ultradian rhythms of the newborn are different than those of an older infant or child. At birth, the circadian rhythm is not fully established; therefore, sleep can occur as easily during the daytime hours as during the night. The normal, full-term newborn sleeps approximately 16 to 18 hours per day (Roffwarg, Muzio, & Dement, 1966). The longest continuous sleep period is 2.5 to 4 hours and the pattern of sleep and wakefulness is irregular. Often, the pattern of sleep is coordinated by feeding times (Adair & Bauchner, 1993).

There are three types of sleep recognized in the newborn: quiet sleep (analogous to NREM sleep), active sleep (REM equivalent), and indeterminate sleep. Quiet sleep is characterized by minimal large or small muscle movements and rhythmic breathing cycles. During active sleep, sucking motions, twitches, smiles, frowns, irregular breathing, and gross limb movements (converse to the typical REM sleep paralysis seen at later ages) are seen. Indeterminate sleep is the period of sleep that cannot be defined by polysomnogram as either active or quiet sleep by predetermined criteria (Sheldon, 2002). As the normal newborn matures, indeterminate sleep evolves into well-defined REM and NREM sleep (Anders et al., 1995).

Compared with older infants and children, newborn sleep architecture differs slightly. In the first few weeks of life, a sleep cycle consists of both active and quiet sleep periods in equal proportion. The sleep cycle lasts 50 to 60 minutes and sleep onset occurs through active (REM) sleep (Anders et al., 1995). Each sleep period lasts only one or two sleep cycles. Thus, sleep periods are shorter and more frequent than in an older child. The newborn has a less efficient sleep cycle than found in older children, resulting in easily interrupted sleep. This lack of efficiency may be a result of the absence of distinct organization into NREM and REM sleep states (Adair & Bauchner, 1993).


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