When do babies sleep through the night?
Many babies, especially newborns, sleep only a few hours at a stretch because they need to waken to be cuddled or fed. Some may start sleeping longer at 4 or 5 months; others may not until after the first year. To help fix this problem, many books tell you to let your baby cry it out beginning in his first few weeks. But by enforcing these sleep-changing programs, you encourage less contact with, and feeding by, your baby.
The safest and most loving way to handle the sleep issue is to feed and cuddle your baby whenever he wakes up and to continue doing so for as long as it works for your family. In other words, make your own rulebook.