How long do four to six month old babies sleep?

Sleep routine. Many babies will start to waken more often at this age as sleep needs decline. A predictable sleep routine will help as will spending naps and nights in their own bed. Almost all will wake in the night and go back to sleep if we let them. Babies over 10 pounds don't need a middle of the night feeding, yet they will learn to wake up and expect a feeding if one is given every night.