Typical sleep patterns for newborns. Newborns sleep a lot – typically up to 16 to 17 hours a day. But most babies don't stay asleep for more than two to four hours at a time, day or night, during the first few weeks of life.ome infants sleep for a long stretch at night as early as 6 weeks, but many babies don't reach that milestone until they're 5 or 6 months old and some continue to wake up at night into toddlerhood.