Things I Wish I Knew About Baby Sleep

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Whether you're expecting or deep in the newborn trenches, there are a few things about baby sleep that can really catch you off guard. Here are the baby sleep facts we wish someone had told us from the start.
Genevieve Titov, Sleep Angel
6 min read |
26 July, 2023

Why newborns confuse day and night

Here's a fun baby sleep fact: newborns can't tell the difference between day and night.
Your baby has just arrived from a cozy home inside the womb, where there were more pressing things to focus on. The internal mechanisms that help your baby tell day from night don't really kick in until around 2 months of age. In those first few weeks, your newborn's main concerns are sleeping and eating. The time of day has very little influence on their sleep cycles or body clock, so don't be alarmed if you find yourself reaching for breakfast at 4am.

The American Academy of Pediatrics recommends keeping night feeds calm and quiet with low lighting to help your baby start recognizing the difference between day and night as their circadian rhythm develops.

How Newborn Sleep Cycles Work

Newborn sleep cycles are around 40 minutes long, compared to about 90 minutes for adults. Where adults move through 4 phases of sleep, babies only have 2. Your baby transitions from light sleep (REM) to deep sleep (NREM) roughly every 40 minutes. It's during the light sleep phase that babies tend to wake up and may need help resettling, until they learn to connect their sleep cycles on their own.

Learn More about Sleep Cycles

Dreamer Tip:

Watch and learn the signs of your baby entering a deep sleep. If you were holding them, a deep sleep can be a more successful time to transfer them to their crib or bassinet.

Babies learn and grow while they sleep

There is so much information for your baby to absorb from the moment they arrive. When babies sleep, their brain isn't just resting. It's growing and consolidating everything they've learned so far. It can be quite a profound moment when your baby seems to have "grown up" while they were sleeping. During light sleep (REM), blood flow to the brain increases and the body ramps up production of nerve proteins that support brain development. This is why sleep isn't just rest for babies. It's actually one of their most important "activities."

How baby sleep develops by age

The good news? Baby sleep matures with time, especially with the help of a consistent bedtime routine. At around 3 months, your baby's sleep cycle phases extend from 2 to 3, resulting in (hopefully) longer stretches of sleep. By 6 months, most babies are capable of joining their brief sleep cycles together for even longer stretches.

If you're in those early weeks and wondering when it gets easier, know that every baby develops at their own pace, but things do improve. A gentle, consistent routine and a safe sleep environment (the AAP recommends room-sharing for at least the first 6 months) can make a real difference as your little one's sleep matures.

How to spot when your baby is ready for sleep

One thing that surprised many of us? Babies have much shorter wake windows than you'd expect, and keeping them up too long can actually make sleep harder, not easier. An overtired baby produces extra stress hormones like cortisol, which makes it tougher for them to settle.

In the early weeks, most newborns can only handle around 45 minutes to an hour of awake time before they need to sleep again. By 3 months, that stretches to about 1.5 to 2 hours, and it gradually increases from there.

Watch for your baby's tired cues:

  • Yawning
  • Turning away from stimulation
  • Jerky movements
  • Rubbing their eyes

Catching these signs early is one of the simplest things you can do to support better sleep. Want to know more? Our guide to overtired signs breaks it all down.

Getting ahead of the game

It may seem obvious, but a little preparation can go a long way. Before your baby arrives (or during a calmer stretch), stock the freezer with easy meals, accept every offer of help, and line up someone you trust who can hold the baby while you nap.

There will be tough nights. Knowing that in advance, and having a plan for when they hit, makes them easier to ride out. The disruptions always pass.

How to build a baby bedtime routine

Bedtime routines give your little one helpful sleep cues so they start to understand what comes next. It takes some time to establish a routine, but it's the repetition and regularity that helps your baby connect the dots. For example, bath, feed, swaddle, sleep are all regular steps before sleep and over time, this creates a daily rhythm for your whole household. Bedtime routines also help reinforce your baby's circadian rhythms, can reduce the impact of sleep regressions, and reduce the need for introducing new sleep aids over time.

Not sure where to start? Our step-by-step guide to building a bedtime routine walks you through it.

Dreamer Tip:

Some days, the routine will go completely out the window. That's normal and it won't set you back. Sometimes you just have to go with your baby's flow.

What is a sleep regression (and why it's actually normal)

Just when you've found a pattern that works, something changes. Sleep regressions can feel frustrating, but they're often called "sleep progressions" because they're usually linked to developmental milestones like rolling. They can also be triggered by illness, a change in routine, or travel.

Common signs of a sleep regression:

  • More frequent night waking
  • Extra fussiness at bedtime
  • Resisting naps or taking longer to fall asleep

Understanding that regressions are a normal part of development helps take the pressure off. You're not doing anything wrong. The best thing you can do is stick with your bedtime routine (or start one if you haven't yet).

Within the first year, most babies experience sleep regressions around:

  • 4 months
  • 6 months
  • 8-10 months
  • 12 months

If your baby is waking more than usual, our article on why babies wake can help you figure out what's going on.

Learning to self-settle

Self-settling is when your baby learns to fall asleep (or fall back to sleep) without needing to be rocked, fed, or held. It's a skill that develops gradually and most babies aren't ready for it until around 6 months of age.

In the meantime, it's completely normal to help your baby resettle when they wake between sleep cycles. Supporting your baby's sleep now doesn't create bad habits. It builds trust and comfort that actually helps them become more independent sleepers down the line. If you're finding it tough, our guide on how to settle a newborn has some practical tips.

How to settle a newborn

Sleep deprivation is real (and it's okay to ask for help)

Babies and sleep deprivation tend to go hand in hand. We've all had a bad night's sleep before, but the constant, round-the-clock nature of caring for a baby is a different level. Sleep deprivation can cause memory lapses, leave you feeling low, and make everyday tasks feel like a challenge. If you or your partner are struggling, please reach out to your doctor, or a trusted family member or friend. You don't need to push through it alone.

Postnatal depression can happen to anyone

Regardless of whether you've experienced depression before, postnatal depression can affect anyone. Postpartum hormones can cause mood swings and leave you feeling depleted or overwhelmed. Maybe the experience of childbirth or early parenthood isn't what you expected. Maybe feeding is harder than you thought.

However you're feeling, your experience is valid, and support is available. If you or your partner are feeling overwhelmed, talk to your doctor, a trusted family member, or a friend. The Postpartum Support International helpline (1-800-944-4773) is also available if you need someone to talk to. You shouldn't hesitate to ask for help whenever you need it.

Key takeaways

Sleep routines don't have to be complicated. Doing a few things in the same order when you can still helps.
Sleep regressions can occur up to 4 times in the first year. They feel hard, but they do pass.
Your baby's sleep will mature with time. What feels impossible at 6 weeks looks very different by 6 months.
Sleep deprivation is harder than you might expect. Seek support if you or your family are struggling to get enough rest.

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  • Understanding Sleep Cycles

    Understanding your baby's sleep cycles is key to fostering restful nights. This article explores how infants' sleep patterns evolve—shifting from short, frequent naps to longer, more consolidated stretches—as their circadian rhythms develop.

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This content has been co-created with experts however should be considered as general information only and not official medical advice.