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

Sleep at Age 1 to 12 Months

Between the ages of 1 to 12 months, circadian and ultradian processes begin to develop into more mature patterns. Around 2 to 3 months, the circadian rhythm emerges (Sheldon, 2002). Infants are increasingly responsive to environmental cues such as the light-dark cycle to synchronize their sleep/wake state organization. Social cues such as timing of feedings and nighttime routines also begin to influence sleep/wake patterns (Anders et al., 1995).

As the infant matures, consolidation of sleep duration and timing is seen during the nighttime hours (Sheldon, 2002). Infants begin to have longer awake periods during the day and forfeit a portion of their REM sleep periods; consequently, the proportion of REM sleep begins to decrease to approximately 30% to 40% of total daily sleep (Roffwarg et al., 1966). However, REM sleep at this age is very efficient and approaches adult quality (Adair & Bauchner, 1993). Around 3 months of age, REM sleep begins to become concentrated in the later sleep cycles of the sleep period and NREM sleep is dominant in the earlier cycles. The NREM sleep organizes and the characteristics of sleep stages 1 through 4 are evident and can be scored. The periodicity of the REM/NREM sleep cycles remains at 50 to 60 minutes (Anders et al., 1995). Sleep onset begins to occur through NREM periods rather than REM periods by 6 months of age, and the propensity for movement during REM sleep is replaced by the typical muscle paralysis (Anders et al., 1995).

As the infant grows, sleep requirements decrease and sleep/wake state organization improves. Nighttime sleep is consolidated and daytime sleep organizes into discrete naps. By 6 months of age, the longest continuous sleep period is usually 6 hours in length (Anders et al., 1995). Generally, two long sleep periods constitute the nighttime sleep period and are typically divided by one nighttime feeding. By the first birthday, children typically sleep 14 to 15 hours per day, with the majority occurring during the night, and the remainder obtained during 1 to 2 daytime naps (Anders et al., 1995).


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