Normal newborn sleep: what’s going on in the 4th trimester
What does normal newborn sleep really mean?
“Sleep when the baby sleeps.”
“You’ll never sleep again!”
“Newborns sleep a lot.”
“Is baby a good sleeper?”
Are these comments familiar? So many people like to share comments about normal newborn sleep, but it rarely comes with realistic, practical information to help parents understand normal sleep in these intense early months. However, understanding sleep in the early months through a developmental and evolutionary lens can dramatically change your perspective on your baby’s sleep. When your perspective shifts, you can support sleep in a way that works with your baby’s biology and leads to more sleep for the whole family.
Biological background: how humans were meant to sleep
Sleep is both biological and cultural. Sleep is a biological bodily function, not something that needs to be taught or learned. At the same time, our culture influences our beliefs about normal sleep – where you should sleep, with whom, when, and how. As very young babies, our children sleep the way that evolution has hard wired them to sleep, and as they grow, their sleep is also shaped by our cultural expectations, daily patterns, and environments.
Humans are primates, and primates are carry mammals. Our babies are hardwired to need continuous close contact in the early months gradually shifting to more independence as children grow. Unlike human babies, primate babies can ensure this proximity by clinging to their mom shortly after birth. Human babies are born less mature than other primates, and they require us to keep them close in the early months through holding or wearing them.
This pattern of care is reinforced by the composition of human milk. Breastmilk is high in lactose and low in protein and fat. It is designed to support rapid brain growth in the early months. Because human milk is quickly digested, babies need frequent feeds day and night.
The need for babies to stay close includes sleep. It is an adaptive, hardwired need that can extend over years. Humans are social sleepers and sleeping near others is normal. Closeness is protective for young babies. It supports frequent feeds and regulates body systems such as temperature, breathing, heartrate, and even stress levels.
One problem is that most western sleep advice treats babies like cash mammals, easily set down in a safe place between feeds. This mismatch between cultural expectations and biology causes a lot of stress.
So what is normal newborn sleep?
Here are some things to keep in mind when you’re not sure if your newborn is “sleeping well.”
Babies usually have a few alert hours after birth followed by a longer period of sleep
Many babies are sleepy over the first 24 hours or so.
The second night after birth many babies are very wakeful and want very frequent feeding. The second or third night is a known tricky time, and things will not always be so intense. This is a great time for an extra pair of arms around to share the baby snuggles.
Sleep is spread across 24 hours in the early weeks meaning that newborns sleep roughly as much during the day as they do at night. Planning to sleep, or at least rest, during the day is important.
Babies sleep in irregular, unpredictable chunks of time.
You will notice more of a difference between day and night sleep as baby approaches 2-3 months.
Baby does not have an established circadian rhythm, so they don’t know the difference between day and night. This emerges around 3-months.
Between newborn to 3-months, babies generally sleep between 14-17 hours across a 24-hour period.
Babies are typically not able to stay awake for long periods, and awake times of 30-90 minutes are common.
Sleep cycles are short, with half of a newborn’s sleep cycle spent in REM sleep. This is protective for young babies.
Baby needs frequent cue-based feeding day and night.
The fourth trimester
The first few months are known as the 4th trimester. Thinking of these months as a time when baby is still gestating but, on the outside, will help put you in the right mindset. Baby thrives when the womb-like environment is replicated. Think about how dramatic the contrast between their uterine environment is with the outside world. Suddenly, they have to wear clothes, regulate their body temperature and breathing, eat, digest, be separate from their parent.
Even if you only hold your baby half the day, that’s a 50% reduction in the amount of closeness they are used to in utero. Baby does not want to be put down, and supporting this contact has many benefits. It is normal for baby to fuss, cry, or immediately wake up when set down. Baby usually sleeps best in arms or worn in a baby carrier. Many families find safe bedsharing or baby on a separate surface but right next to the adult bed to be good nighttime options.
Witching hour
Many babies have a period of increased fussiness, cluster feeding, and generally being out of sorts in the late afternoon or evening. This can start a few weeks after birth, peak between 6-8 weeks, and generally eases off by 3 months. This is often known as the witching hour.
Ways to support sleep in the fourth trimester:
You can use social cues to help differentiate day and night by keeping daytime light and with normal sound while nighttime is dark and quiet.
Get outside every day. Let lots of natural sunlight into your home.
Sleep is irregular and trying to force a sleep schedule is likely to cause stress. Learning and following your baby’s cues is important.
Nursing to sleep is normal, healthy, and a great tool.
Drowsy but awake does not work for most babies and is not something to stress over. Use the soothing tools that work for you now. You can always change them later if you need or want to do so. You can read more about this sleep myth here.
What’s happening to your baby’s sleep by three months
Baby may be sleeping 9-10 hours at night with several wake ups.
Baby may have 4-5 hours of daytime sleep spread over 4 or more naps
Baby may be able to stay awake for 1-2 hours at a time.
According to a large study the majority of 3-month-old babies wake on average 2.2 times a night. Only 16.5% of babies slept through the night (Paavonen et al., 2020)
Circadian rhythm (body clock) starts to emerge.
Regular night waking and feeding is normal and healthy, although longer sleep stretches of 4-6 hours at night are common.
Longer sleep stretches at this age does not mean that your baby will always be able to sleep that long.
Short naps, contact naps, motion naps, and nursing to sleep are all normal.
Sleep is dynamic in the first year, so however your baby is sleeping at 3- months, expect it to change!
If you’d like more specific information and suggestions individualized to your family, I offer a 1-hour sleep consult for young babies. Or, if you’d like to talk first about my approach before scheduling a session, you can schedule a free intro call .