By four months, most babies begin to show some preferences for longer sleep at night. By six months, many babies can go for five to six hours or more without the need to feed and will begin to "sleep through the night."
As newborns get older, they'll nurse less often and have longer stretches between feedings. Newborn babies who are getting formula will likely take about 2–3 ounces every 2–4 hours. Newborns should not go more than about 4–5 hours without feeding.
Newborn: every 2 to 3 hours. At 2 months: every 3 to 4 hours. At 4 to 6 months: every 4 to 5 hours. At 6+ months: every 4 to 5 hours.
As a guide, many babies sleep 14-20 hours a day in the first weeks. By 3 months many are settled into a pattern of longer sleep times – perhaps 4 to 5 hours at night. When a baby sleeps about 5 hours straight, this is considered 'sleeping through the night'.
This can be a sign of illness, infection, or low blood sugar. Infants dehydrate easily and not eating can quickly turn into a medical issue. Generally, they shouldn't go without feeding for longer than five hours for their first 12 weeks.
For the first few days you may need to wake them to feed if they are still sleeping by 3 hours from the last day feeding and 4 hours at night. If baby still won't eat, allow baby to sleep another hour and try again to wake and feed them.
Don't worry, baby will ask to be fed as usual as soon as his stomach feels empty again. Your baby may be constipated and appear less hungry than usual, however once this passes everything will go back to normal. Or it may just be that your baby was enjoying the sleep and took longer to wake up.
Newborns don't have an established circadian rhythm or body clock. Being able to establish a pattern of day and night depends on neurological development. This means your baby could take up to twelve weeks before he settles into a more predictable pattern of longer sleeps at night and waking during the day.
Generally, newborns sleep a total of about 8 to 9 hours in the daytime and a total of about 8 hours at night. But because they have a small stomach, they must wake every few hours to eat. Most babies don't start sleeping through the night (6 to 8 hours) until at least 3 months of age.
From a developmental perspective, babies are able to sleep through the night — defined as a six- to eight-hour stretch — without eating when they're between 4 and 6 months old. In this age range, most babies reach the 12- to 13-pound mark, the weight where they no longer metabolically need nighttime feedings.
Generally, newborns sleep about 8 to 9 hours in the daytime and about 8 hours at night. But they may not sleep more than 1 to 2 hours at a time. Most babies don't start sleeping through the night (6 to 8 hours) without waking until they are about 3 months old, or until they weigh 12 to 13 pounds.
Most newborns need eight to 12 feedings a day — about one feeding every two to three hours. While waking up a sleeping baby might seem like a bad idea, frequent feedings early on are important for a couple of reasons: Crying is a late sign of hunger.
In the first few weeks of life, breastfeeding should be "on demand" (when your baby is hungry), which is about every 1-1/2 to 3 hours. As newborns get older, they'll nurse less often, and may have a more predictable schedule. Some might feed every 90 minutes, whereas others might go 2–3 hours between feedings.
Newborns usually sleep in short bursts of 2-3 hours each. Some newborns sleep for up to four hours at a time. Newborns wake frequently to feed because they have tiny tummies. Your newborn might go straight back to sleep after feeding or they might stay awake long enough for a short play.
In general, you can expect your baby to sleep an hour per week old they are, starting about 5 weeks old. So, a 5-week-old may be able to go 5 hours, a 6-week-old may be able to go 6 hours, and so on.
Your baby is sleeping longer at night—as many as four to six hours at once, if you're lucky—and you're having longer awake and alert phases during the day. Your baby might prefer to sleep for a few hours after eating and then wake up to play for an hour or two before getting hungry again.
“Babies can still breastfeed on demand—usually they will want to breastfeed every 2-4 hours at this stage,” she notes. “But sometimes they will want to feed every hour and other times will not eat for 5 hours.” All of this is common, she says.
Newborns who sleep for longer stretches should be awakened to feed. Wake your baby every 3–4 hours to eat until he or she shows good weight gain, which usually happens within the first couple of weeks. After that, it's OK to let your baby sleep for longer periods of time at night.
Although newborns generally sleep 16-18 hours each day, unusual sleepiness may be an indication that your baby is underfed.
Babies around two weeks old can usually sleep for longer stretches in 24 hours. So I like to recommend waking your baby during the day to feed.
Your baby needs to gain weight
Not getting enough to eat can slow down newborn weight gain. Newborns typically lose between 5 and 10 percent of their body weight, depending on delivery method, in the days after birth. They need to spend the first few weeks gaining it back.
The amount of sleep an infant gets at any one stretch of time is mostly ruled by hunger. Newborns will wake up and want to be fed about every three to four hours at first. Do not let your newborn sleep longer than five hours at a time in the first five to six weeks.
At first, babies need to eat about every 2 to 4 hours to help them get enough nutrition and to grow. This means you may need to wake your baby to feed. You can try patting, stroking, undressing, or changing the diaper to help wake your baby.
Newborns and young babies should be fed whenever they seem hungry. This is called on-demand feeding. After the first few days of life, most healthy formula-fed newborns feed about every 2–3 hours. As they get bigger and their tummies can hold more milk, they usually eat about every 3–4 hours.