Newborn Sleep Patterns
Your infant's sleep patterns are nothing like yours. First, his sleep includes a higher percentage of REM; at 3 months, your newborn spends 50 to 80 percent of sleep time in REM, compared with your 20 percent. Second, his sleep cycles run approximately 50 minutes; yours 90.
All of this means that your newborn will wake up easily, sleep for shorter periods -- no more than three to four hours, and maintain his light, disordered "pattern" around the clock.
Of course, if your baby's awake, so are you, which means you're on call throughout the night to feed and comfort him. This type of sleep deprivation, typical of parents of newborns -- where over the course of eight hours you're up two or three times for 20 minutes (or longer) -- is even more grueling than getting just five hours of straight sleep. Why does the number of awakenings matter more than total hours? For one, sleep fragmentation causes a significant decrease in your deep sleep. That's because each time you get up and then go back to bed, you have to start the sleep cycle all over again, entering the light stages before you return to deep sleep. The result: exhaustion.