Dr. Sarah Mitchell
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Newborn Sleep Mastery: A Parent's Guide to Understanding and Improving Sleep Patterns

Understanding newborn sleep patterns to help your baby sleep

Newborn sleep can be confusing and frustrating for parents. While we all know sleep is critical for babies' development and health, their sporadic sleep cycles and frequent night wakings can leave caregivers exhausted and desperate for a full night's rest.

To help you better understand your newborn's sleep patterns and needs in the first year of life, this post will cover baby sleep patterns, newborn sleep architecture, sleep regressions and provide tips to help your baby (and you!) get good, healthy sleep.

What is a newborn?

  1. A newborn is typically defined as a baby from birth to about 2 months of age. However, some sources may extend the newborn phase to 3-4 months.

Newborn Sleep Architecture

  1. Newborns spend about 50% of sleep in REM and 50% in non-REM. The amount of REM sleep declines to about 25% by 6 months of age as non-REM sleep increases.
  2. Non-REM sleep transitions from easier to deeper stages as the sleep period progresses. Newborns have more active REM early in the night and more restorative deep sleep later.

Newborn Babies REM Sleep 

REM cycles last around 50-60 minutes in newborns.

Here are some common actions and behaviors that newborns may display during REM sleep:

  1. Rapid eye movements - their eyes will move quickly back and forth under their eyelids.
  2. Irregular breathing - breathing may be more irregular, sporadic, or even pause temporarily.
  3. Facial or body twitches - cheeks, lips, fingers and limbs may twitch or jerk subtly.
  4. Grimace or smile - facial expressions like smirks or smiles may appear briefly.
  5. Noise - occasional grunting, sucking noises, cries or whines can happen.
  6. Head/arm movements - their head or arms may jerk or shift position suddenly.
  7. Heart rate and BP changes - increases in heart rate and blood pressure are common in REM sleep.
  8. Morning erections - erections present at birth disappear after a few months but may still occur in REM sleep.
  9. Sleep talking/crying - making sounds or even crying out without fully waking up can happen later on.
  10. Difficulty waking up - it can be harder to wake a newborn up from REM vs non-REM sleep.

While REM sleep may appear active with random muscle movements, newborns remain asleep during it. These actions are involuntary and not under their conscious control.   Those smiles that you thought were due to gas?  Actually due to REM sleep.  The rest of their sleep is spent in quiet or non-REM sleep.

Non-REM Sleep 

Non-REM sleep is divided into stages ranging from light to deep sleep. Stage N1 is the lightest sleep where your baby can be easily awakened. N2 is slightly deeper sleep marked by sleep spindles and slower brain waves. Stages N3 and N4 are the deepest, most restorative stages of non-REM sleep.

Non-REM cycles range from 30-45 minutes. 

On average, newborns need a total of 16-20 hours of sleep per 24-hour period, including naps.

Newborn Sleep Patterns

One reason newborn sleep is so confusing is that infants don't have an established circadian rhythm or sleep-wake cycle in the first few months of life. They simply sleep when tired, then wake up hungry. One study shows that ""The newborn period is highly disorganized with no clear circadian rhythms discernible for sleep–wake, feeding behavior, or stability in individual differences. It is not until approximately 6–8 weeks of age that a more adult-like circadian sleep–wake pattern begins to emerge."  Newborns sleep in short cycles of 1.5-4 hours, alternating between REM and non-REM sleep. Frequent night wakings every 2-3 hours are developmentally the first month and due to their small stomachs needing more frequent feedings.

The 4th Trimester Concept

The "4th trimester" concept recognizes that babies are born developmentally premature, about 3 months early compared to other mammals. Babies this young need constant contact, comfort, and reassuring motions to regulate their sleep and mimic the womb environment.

According to an article in the journal, Midwifery Today, "The human infant is born in a developmentally immature state compared to other mammals. This is called the "exterogestate" by anthropologists, meaning the gestation period extends beyond the womb after birth. The fourth trimester concept suggests that human infants need 3 additional months of development after birth to reach a level of maturity comparable to other species." During this period, babies require frequent parental contact, touch, and movement to regulate physiology, sleep cycles, and neural development.

The article goes on to state:

"To facilitate the transition from the womb, caregivers should mimic qualities of the intrauterine environment through techniques like swaddling, side/stomach positioning, shushing, swinging, and increased physical closeness during the first 3-4 months or 'fourth trimester' of development."

Techniques like swaddling, pacifers and rocking can help satisfy a newborn's need to recreate the snug, rhythmic sensations of the womb and result in better sleep.  In our best selling Amazon book, The Helping Babies Sleep Method; The Art and Science of Teaching Your Baby to Sleep we review step by step approaches to getting your baby to fall asleep in the crib/bassinet and falling asleep from awake with less and less help as they age. 

More on circadian rhythms:

  1. While newborns don't have an established circadian clock, they are not completely arrhythmic. Around 2-3 weeks, some circadian patterns like longer night sleep emerge.
  2. By 3 months, melatonin secretion patterns start becoming more robust and night/day cycles consolidate. Circadian rhythms continue maturing through infancy.

According to an article in the Journal of Perinatology:

"While newborns do not show clear circadian patterns, they are not entirely arrhythmic at birth. Around 2-3 weeks, newborns exhibit some rhythmicity like longer night sleep bouts.

However, circadian rhythms are still immature. Research shows melatonin secretion does not demonstrate circadian variation until around 8-12 weeks of age.

By 3 months, melatonin levels begin to show a more distinct rise at night, stabilizing night and day cycles. Maturation continues as infants approach 6 months old."

The source further states:

"Circadian rhythms in early infancy are quite fragile. Continued development and consolidation of circadian rhythms occurs across the first year of life and is influenced by external factors like light exposure and feeding schedules."

Here are some details on how external factors like light and feeding impact circadian rhythm development in infants:

Light Exposure

  1. Exposure to daylight helps entrain infants' developing circadian clocks and consolidates day/night cycles.
  2. Brighter light exposure during daytime activities and feedings and dim lighting at night is recommended.
  3. Limiting blue light exposure from screens/devices in the evening can help preserve melatonin release.
  4. Studies show scheduled daily outdoor light exposure stabilizes rhythms at a younger age.

Feeding Schedules

  1. Circadian rhythms can be influenced by timing of feedings and whether they occur during day or night.
  2. Clustering daytime feeds and spacing them further apart at night can help strengthen circadian patterns.
  3. Nighttime feeds should happen with minimal stimulation and light.
  4. As solids are introduced, mealtimes should align with desired wake times.
  5. By 6 months, feeding smaller volumes at night supports circadian maturation.

So in summary, factors like properly timed light exposure, daytime activity, and consolidated nighttime feeds help reinforce circadian rhythms in developing infants during the first 6 months of life.

Here is a source that provides evidence supporting the impacts of light exposure and feeding schedules on infant circadian rhythm development:

According to a review published in the Journal of Biological Rhythms:

"Animal and human studies suggest that circadian rhythms in early infancy can be entrained by external factors. However, very few studies have examined how light, feeding and maternal cues shape infants’ developing biological clock.  A study on 3-week old infants found that just 5 days of scheduled daily outdoor light exposure promoted earlier onset of melatonin release. This suggests light can quickly consolidate circadian rhythms. Another study revealed cluster scheduling of daytime feeds led to increased rhythm robustness at 6 weeks compared to random or evenly spaced feeds.

Research on breastfed infants showed scheduled breastfeeding during daylight hours and restricted night feeds promoted circadian entrainment."

What does all that mean? As early as one month of age you can start using light and dark to denotate awake times versus sleeping times including daytime naps.   Getting on more regular feeding schedules in the daytime can help your night sleep.  In the Helping Babies Sleep Method, this is pillar 3 - being an intentional feeder.  The idea of using food for fuel rather than to soothe.  Not that you can't soothe with food but that you're intentionally feeding in the daytime to fill up on calories to help facilitate longer stretches of sleep at night. 

Tips for Better Newborn Sleep

Here are some tips to help your newborn get the healthy sleep they need:

  1. Establish a calming pre-bed routine like swaddling, nursing/bottle, soft music or lullaby. Be consistent with it.
  2. Use daylight exposure and activity during the day to help set their circadian rhythm.
  3. Avoid overstimulation and overtiring baby - watch for tired cues like yawning and rubbing eyes.
  4. Grab our sleep summary by age cheat sheet to get guidelines on how long your baby can comfortably stay awake between naps. 
  5. Allow newborns to wake and eat during the night as needed. Don't try to sleep train yet.
  6. Ensure the sleep environment is safe - alone, on their back, in a crib free of blankets and toys.

In our best selling Amazon book, The Helping Babies Sleep Method; The Art and Science of Teaching Your Baby to Sleep we review step by step approaches to getting your baby to fall asleep in the crib/bassinet and falling asleep from awake with less and less help as they age.   The biggest tip - after 1 month of age work on having feeding away from sleeping and helping with rocking, patting, or shhing to help your baby fall asleep from awake in the place they will be sleeping.  This simple action alone is a game changer and can help you minimize the impact of the 4 month sleep regression. 

The First 3 Months: 0-3 Months Sleep Patterns

Newborn sleep architecture

  1. At birth, newborns spend about 50% of sleep in active REM sleep. REM predominates sleep in the first few months.
  2. Around 2-3 months of age, the amount of REM sleep starts to decrease as non-REM/quiet sleep increases.
  3. By 6 months, only about 25-30% of an infant's sleep is REM sleep, compared to the 50% mark seen in newborns.

Non-REM sleep changes:

  1. In newborns, non-REM sleep lacks distinct stages. It gradually becomes more organized.
  2. At 2 months, non-REM sleep starts to show clear cycles of light (N1-N2) and deep (N3) stages.
  3. By 6 months, non-REM cycles are even more mature, with increasing amounts of deep, restorative sleep later in the night.

So in summary, the architecture of newborn sleep starts shifting around 2-3 months as non-REM sleep becomes more prominent and organized into clear cycles.

In the first months of life, newborn infants have an inconsistent sleep-wake cycle. They need to eat frequently around the clock due to small stomach capacity and rapid growth. During the first month, expect a newborn to sleep an average of 15-17 hours per day but only 1-3 hours at a time. 

By months 2-3, total sleep declines to 14-15 hours per day as babies become more alert. At this stage, sleep is divided between night sleep (6-8 hours) and 2-5 naps per day ranging from 30 minutes - 2 hours long. 3 months marks a key developmental milestone as babies learn to fall asleep independently without being rocked or fed to sleep.

3-6 Month Sleep Patterns and Regressions

Between 3-6 months, babies consolidate their night and day by sleeping more at night and taking fewer, longer naps. Around 4 months, expect 11-15 hours of night sleep and 30-90 minute nap periods.

Unfortunately, the 4 month sleep regression also strikes as babies' sleep cycles mature. To get through this disruption, stick with sleep training foundations like routines and not letting baby cry it out endlessly. By 6 months, total sleep need is around 14 hours.

6-12 Month Sleep Patterns and Regressions

From 6-12 months, babies practice important independent sleep skills like self-soothing and learn to sleep for longer stretches at night. At 6 months, infants should be capable of sleeping through the night with a 10-12 hour sleep period. Naps decrease to about 2 per day.

Around 8-10 months, separation anxiety, teething, and new motor skills like crawling may cause more frequent night wakings. Be flexible and offer extra comfort until the regression passes. By 12 months, most babies only need 1-2 naps and sleep 11-12 hours at night consistently.

Toddler and Child Sleep Needs (12 months - 5 years)

As children grow into the toddler and preschool years, their sleep needs decrease but healthy sleep habits remain crucial for development, behavior, and immunity. Here are the recommended hours of sleep needed:

  1. 1-2 years: 11-14 hours
  2. 3-5 years: 10-13 hours
  3. 5-12 years: 9-12 hours

Even though daytime sleep decreases, consistency with bedtime routine and routine nap times reinforces the circadian rhythm and leads to better nighttime sleep. Aim for an earlier bedtime than older kids.

Common Newborn Sleep Regressions

Around 2 weeks, 6 weeks, and 3-4 months of age, 8-10 months and beyond it is common for babies to go through sleep regressions. Sleep regressions involve acute disruptions in a baby's sleep cycle, resulting in frequent wakings, difficulty falling asleep, and reduced sleep time.  Anytime you hear sleep regression, think GROWTH AND DISTRACTION.  Your baby is growing physically by getting teeth or neurologically with brain development that ranges from growth spurts, learning new concepts such as object permanence or acquiring new skills.

According to an article published in Sleep Medicine Clinics:

"Sleep regressions in infants are often linked to major developmental milestones or growth spurts. For example, the regression around 4 months coincides with emerging social skills and increased awareness of surroundings. Regressions around 8-10 months coincide with separation anxiety and new motor skills like crawling.

These developmental advancements result in changes to sleep architecture and disruption of neural connections controlling sleep cycles. Immature sleep-wake mechanisms also make infants prone to regressions at transition points.

During regressions, it is common to see:

  1. Decreased sleep consolidation
  2. More frequent night wakings
  3. Shorter stretches of deep sleep
  4. Difficulty falling/staying asleep

While regressions can be challenging, they are temporary disturbances resulting from maturation of biological sleep mechanisms and brain development."  In addition, they don't mean that your baby can't sleep, it means they might be distracted or harder to help to sleep.   Lastly, your 6 month sleep regression when your LO gets teeth might be your friends 8 month sleep regression since teething varies child to child.  There are no absolutes in timing with sleep regressions. 

In our best-selling Amazon book, The Helping Babies Sleep Method; The Art and Science of Teaching Your Baby to Sleep we review step-by-step approaches to getting your baby to fall asleep in the crib/bassinet and falling asleep from awake with less and less help as they age.   This book is for babies from a few weeks old up until 24 months of age. The biggest tip - after 1 month of age work on having feeding away from sleeping and helping with rocking, patting, or shhing to help your baby fall asleep from awake in the place they will be sleeping.  This simple action alone is a game changer and can help you minimize the impact of the 4 month sleep regression. 


Hopefully, this overview gives you a better understanding of the various stages of newborn sleep cycles and patterns. While sleep in the first year can be extremely challenging and confusing for new parents, remember that phases like regressions are temporary. Stick with healthy sleep habits and routines and consult our other blog posts and youtube channel for more resources.  You can always work 1:1 with Dr. Sarah if you're looking for high touch coaching to reach your goals during this exhausting period.

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