Everything You Need To Know About Baby Sleep Cycles

Written by: Julian Wood



Time to read 7 min

Embarking on the journey of newborn sleep can often feel like venturing into uncharted territory. It's well-known that the sleep needs of a baby differ significantly from those of an adult.

It’s also no secret that getting your baby into a good sleep routine is one of the most challenging parts of parenthood, especially for first-time parents. Things can become overwhelming pretty quickly, and it’s easy to get caught up in sleepless nights and foul moods.

But by delving deeper into the sciences behind your precious little one's sleep patterns, you’ll start to understand your baby’s sleep needs more and hopefully figure out the best way to drift them off into a peaceful slumber.

Baby sleep cycles are a major part of understanding your baby’s nighttime habits, so that’s where we’re going to start.

What is a Sleep Cycle?

A sleep cycle refers to the natural internal process, or our circadian rhythm, that enables us to sleep and wake at routine intervals.

Newborn babies experience only two sleep stages: REM and non-rapid eye movement sleep, and they spend approximately 50% of their sleep time in the REM stage.

As newborns can sleep up to around 16 hours per day, they typically experience up to nine hours of REM every 24 hours. As babies grow, they gradually spend less time in the REM stage of sleep and begin to adapt to the same sleep stages as adults.

Unique Aspects of Baby Sleep Cycles

Shorter Cycles

Babies have shorter sleep cycles than adults. While an adult's cycle might last about 90 minutes, a baby's can be as short as 30-50 minutes.

More REM Sleep

Newborns spend about 50% of their sleep in the REM stage, which is much higher than in older children and adults. This percentage decreases as they grow.


There's a lot of variability in sleep patterns among babies. Some might have longer or shorter cycles, and the distribution between NREM and REM can vary.

The Stages of Baby Sleep

Newborn babies experience two primary stages of sleep that cycle throughout their rest period: Non-Rapid Eye Movement (NREM) sleep and Rapid Eye Movement (REM) sleep.

During each stage of slumber, their sleeping behavior will differ, like they make wake up easier or they’ll be deep in sleep (in which case, it’s probably a good time for you to catch up on Z’s, too).

Stage 1: NREM Sleep

In young babies, NREM sleep can be broken down into three main stages. Understanding these stages can help you understand the type of sleep your baby is getting and adapt to their naps.

Sleep Stage Description Characteristics
Stage 1 (N1) Lightest stage of sleep Hard to distinguish in babies.
May drift in and out of sleep.
Possible movement or open/semi-open eyes.
Stage 2 (N2) Stable sleep stage More stable breathing and heart rate.
Less responsive to the environment.
Significant portion of sleep.
Stage 3 (N3) Deep sleep (slow-wave sleep) Most restorative stage.
Less likely to wake up from disturbances.
Body grows, repairs tissues, builds bone and muscle, & strengthens the immune system.

Stage 2: REM (Rapid Eye Movement) Sleep:

Known for its characteristic rapid eye movements, this is a more active sleep stage where dreaming occurs.

For babies, REM sleep is crucial for brain development. They spend a higher proportion of their sleep in REM compared to adults. During REM, the brain processes information, supports learning, and stimulates areas of the brain essential for development.

How Much Will My Baby Sleep? A Month-By-Month Breakdown

The amount of sleep a baby gets varies greatly in the first year, and it’ll differ between children. But here’s a general guide to help you understand how much your baby should be sleeping at different stages of their development.

Age Range Total Daily Sleep Notes
Newborn 16-18 hours Sleep is in several short periods throughout the day and night. Feeding is a priority over sleep.
1-2 Months 15-16 hours Begin to sleep for longer stretches. Includes naps.
3-4 Months 14-15 hours Develop more regular sleep patterns. Total daily sleep drops slightly.
5-6 Months 13-14 hours Night-time sleep periods become longer, often 10-12 hours.
7-9 Months 12-14 hours Sleep consolidates more, including one to two naps.
10-12 Months 11-14 hours Require about 11-14 hours of sleep a day, including a couple of daytime naps.

Note: every baby is unique, and these figures are averages. Some babies may sleep more or less than the guideline suggests.

How to Recognise Sleep Regressions

Sleep regressions are periods when a baby who has been sleeping well suddenly starts waking up at night or skipping naps for no apparent reason. Recognising these regressions can help reassure parents that this phase is a normal part of their baby's development.

Common signs of baby sleep regression include:

  • Your baby is suddenly waking up multiple times during the night.

  • There's a notable change in their nap length, either skipping naps or taking shorter ones.

  • The baby seems unusually fussy and difficult to soothe to sleep.

  • There's increased tiredness during the day due to a lack of restful sleep.

When Sleep Regressions Commonly Occur

While every baby is unique and sleep patterns can vary greatly, there are common ages when sleep regressions typically occur.

Generally, these periods align with significant growth and development milestones.

Age Range Sleep Regression Causes
4 months Transition to adult-like sleep cycles. Babies start cycling between light and deep sleep, leading to more frequent night awakenings.
8-10 months Developmental milestones, such as crawling. Increased exploration and FOMO (Fear of Missing Out) may lead to resistance to sleep.
12 months Learning to walk and other developmental leaps. Significant developmental changes can disrupt sleep patterns.
18 months Molars are coming in, separation anxiety, desire for independence. Physical discomfort and emotional challenges contribute to sleep disturbances.
2 years Transition from crib to bed, potty training, the arrival of a sibling. Multiple significant changes can disrupt the child's sleep routine and sense of security.

It's important to remember that sleep regressions are temporary. With patience, consistency, and lots of comfort, your little one will return to a more predictable sleep pattern. But you can also get in touch with your pediatrician if you are concerned.

Why Understanding Your Baby's Sleep is Important

Understanding your baby's sleep is crucial for both their health and development as well as your own well-being. Better understanding your baby's sleep cycles can make it easier for you to support them as they adjust to the changes.

Proper sleep is essential for babies as it promotes cognitive and physical development. It aids in brain maturation and is a key time for learning consolidation. Also, well-rested babies tend to be happier and more settled, leading to a more harmonious household.

While restless sleep can be typical sleep behavior and developmentally appropriate at times, if your baby is restless at night for an extended period of time, it can be worth consulting your primary healthcare provider.

As parents, understanding your baby's sleep patterns can help you better predict their needs, plan your day and potentially get more rest yourself. If your baby is sleeping well, there's a higher chance you will be too!

Create the Perfect Sleep Environment With Snüz

Navigating through the terrain of baby sleep cycles can indeed seem daunting at first. But you can provide the best care for your little one by understanding your baby's sleep stages, recognising sleep regressions, and adjusting to changing sleep patterns.

It's essential to be patient and flexible during this journey to ensure you have happy and healthy sleep.

Check out our blog for more advice on baby sleep, parenthood, and nursery design tips.


Why Do Babies Move So Much in Their Sleep?

Your baby moves a lot in sleep primarily due to their high proportion of REM sleep, the phase associated with dreaming and brain development. This is why you might witness restless newborn sleep.

These movements can also indicate a transition between sleep cycles or a response to external stimuli. Note that consistent, drastic movement may signal discomfort, so it's crucial to monitor your baby and ensure their sleep environment is safe and comfortable.

How Long Should a 2-month-old Sleep?

A 2-month-old baby typically sleeps for about 15-16 hours a day, including naps. The sleep duration can be spread across multiple short periods due to the baby's feeding needs. It's important to remember that every baby is unique, and sleep patterns can vary, so take time to sync with your baby's needs.

Why is My Baby Fussy at Night?

Nighttime fussiness in babies could be due to various reasons, including hunger, a dirty nappy, teething, or even sleep regressions. Overstimulation or overtiredness might also affect their ability to settle.

It's crucial to keep a consistent bedtime routine, ensure a calm sleep environment, and address any physical discomforts to help soothe your baby. It's normal to have some trial and error to figure out what works best.

Why is My Baby So Restless While Sleeping?

Restlessness in babies during sleep can be caused by various factors such as growth spurts, developmental milestones, or changes in their sleep patterns. It could also be due to environmental factors like the room temperature, noise, or discomfort from a wet nappy.

Monitor your baby's sleep behaviors, keep a consistent bedtime routine and consult a pediatrician if you have ongoing concerns.

Should I Wake My 2-month-old to Feed?

A 2-month-old baby should be fed on demand, typically every 2-3 hours or 8-12 times a day. However, if your baby is sleeping and not showing signs of hunger, it's generally okay to let them sleep for up to 4 hours at a time.

Always consult with a healthcare provider if you have specific concerns about your baby's feeding schedule.