By the end of their third month, most babies can sleep up to 10 hours at night without waking to be fed. However, they may need a little sleep training to get to that point.
Feeding your baby when he’s hungry helps regulate his day, setting the stage for him to be alert and happy during playtime and sufficiently tired when it’s time to sleep. For the first few months, it’s normal for your baby to feed every two to four hours (alas, even at night) and sleep most of the rest of the time. With each passing month, his daytime alertness increases and, hopefully, his nighttime sleep hours do, too.
By the end of their third month, most babies can sleep up to 10 hours at night without waking to be fed. However, they may need a little sleep training to get to that point. It helps to establish a bedtime routine, making the feeding that naturally falls between 7 P.M. and 9 P.M. (a good bedtime for later in life) a special one. For instance, give him a bath and a gentle massage with moisturizer, put him in pajamas, turn out the lights, and then feed him and put him to bed. Think of it as the three b’s: bath, breast or bottle, and bed. Because he is eating and sleeping every two to four hours around the clock, this routine helps him begin to make a distinction between day and night—and, hopefully, will allow him to sleep for longer stretches.
While your baby still needs nighttime feedings, it helps to make them different from daytime feedings. When you feed your baby in the late night hours, after he’s already been asleep, keep stimulation to a minimum. Don’t turn on bright lights; use a nightlight instead. Keep talking to a minimum and use a low, calm voice.
It’s a myth that giving your baby cereal before he’s 6 months old will help him sleep better at night, and it is important to note that this practice is not recommended. Your baby’s body isn’t yet ready to take in or process solids.
—Scott Cohen, MD, pediatrician and author of Eat, Sleep, Poop: A Common Sense Guide to Your Baby’s First Year