Newborns spend about an equal amount of time in light sleep and deep sleep, in about 50 to 60 minute cycles. Initially, newborns may wake with each cycle, or every one or two hours. Sleep patterns change as babies get older.

Why is my newborn a heavy sleeper?

Newborns have small stomachs, so they get full quickly. Whether you're breast-feeding or formula-feeding, being held close and comfortably enhances their sleepiness. This can cause them to fall asleep before they're full. As a result, they might wake up often to eat.

How do I know if my newborn is sleeping too much?

Chronic sleepiness, though, can sometimes be a cause for concern. If your newborn is regularly sleeping for more than 17 hours a day and is interfering with her ability to eat at least eight times per day, you should let your pediatrician know. Frequently missing meals could hurt her weight gain and growth.