Your baby's brain doubles in size during the first year. Most of that growth happens while they sleep. This guide covers everything from safe sleep practices to navigating regressions and building healthy habits that last — all backed by peer-reviewed research and the AAP's 2022 guidelines.
Last updated: February 2026
14-17 hrs
Sleep needed (newborns)
ABCs
Alone, Back, Crib (safe sleep)
50%
Of newborn sleep is REM (brain-building)
Why Infant Sleep Is the Foundation of Brain Development
Here's something most parents don't realize: a newborn's brain is roughly 25% of its adult size at birth. By the end of the first year, it's approaching 70%. That growth doesn't happen during tummy time or while staring at a mobile. It happens during sleep.
During REM sleep — which accounts for about 50% of a newborn's total sleep time, compared to 20-25% in adults — the brain consolidates new experiences, builds neural pathways, and releases growth hormones critical for physical development. This isn't optional downtime. It's construction time. Every hour of quality sleep is an hour of active brain-building.
Sleep also regulates cortisol, the stress hormone. Chronically disrupted sleep elevates baseline cortisol, which can impair memory formation and emotional regulation — even in infants. The research is clear: protecting your baby's sleep is one of the highest-impact things you can do for their developing brain.
Sleep Deprivation Compounds
Research on infant colic and long-term outcomes found that persistent sleep disruption in infancy is associated with higher rates of sleeping problems even in adolescence (PMID: 39729888). Early sleep patterns aren't just a phase — they can set trajectories.
Safe Sleep: The ABCs That Save Lives
The American Academy of Pediatrics updated their safe sleep recommendations in 2022, consolidating decades of research into clear, actionable guidance (Moon RY et al., Pediatrics, 2022; PMID: 35726558). The core message is simple enough to remember as ABCs.
The ABCs of Safe Sleep
A
Alone
Baby should sleep alone in their own sleep space. No blankets, no pillows, no bumpers, no stuffed animals. Room-sharing (not bed-sharing) is recommended for at least the first 6 months, ideally 12.
B
Back
Always place baby on their back for every sleep — naps and nighttime — until they can independently roll both ways. Back sleeping alone reduces SIDS risk by more than 50%.
C
Crib
A firm, flat sleep surface — crib, bassinet, or play yard — that meets CPSC safety standards. The only thing on the mattress should be a fitted sheet. No inclined sleepers, no positioners, no dock-a-tots for unsupervised sleep.
These aren't suggestions. They're the single most important thing you can do to reduce the risk of sleep-related infant death. Every other tip in this guide is secondary to this one.
Additional AAP Safe Sleep Recommendations
Room-share for at least 6 months. Sleeping in the same room (but not the same bed) reduces SIDS risk by up to 50%.
Offer a pacifier at sleep time. After breastfeeding is established (around 3-4 weeks), offering a pacifier is associated with reduced SIDS risk. Don't force it if baby refuses, and don't reinsert after baby falls asleep.
Avoid smoke exposure. Prenatal and postnatal smoke exposure significantly increases SIDS risk. This includes secondhand and thirdhand smoke.
Don't rely on home monitors. The AAP does not recommend commercial cardiac/respiratory monitors as a strategy to reduce SIDS risk.
Breastfeed if possible. Any breastfeeding is associated with reduced SIDS risk; exclusive breastfeeding provides the greatest protection.
How Much Sleep Does Your Baby Actually Need?
Sleep needs shift significantly across the first year. These guidelines come from the American Academy of Sleep Medicine and represent healthy ranges — not rigid targets. Your baby's needs may fall at either end.
Age
Total Sleep (24 hrs)
Daytime Sleep
Number of Naps
Wake Window
0-3 months
14-17 hours
7-9 hours
4-5+ (irregular)
45 min - 1.5 hrs
3-6 months
12-16 hours
3-5 hours
3-4 naps
1.5-2.5 hrs
6-9 months
12-15 hours
2.5-4 hours
2-3 naps
2-3.5 hrs
9-12 months
12-15 hours
2-3 hours
2 naps
3-4 hrs
A note on the 0-3 month range: the AASM does not issue formal recommendations for infants under 4 months because of the wide variability in normal newborn sleep. The 14-17 hour figure comes from the National Sleep Foundation and represents typical ranges.
Wake Windows: The Overlooked Key to Better Sleep
Wake windows are the stretches of time your baby can comfortably stay awake between sleep periods. Get them right and your baby falls asleep relatively easily. Miss them and you're dealing with an overtired baby who, paradoxically, fights sleep harder.
Overtiredness triggers a cortisol surge — the body's stress response — which makes it harder to fall asleep and stay asleep. This is why the baby who "should be exhausted" is screaming instead of sleeping. They blew past their window.
Age
Wake Window
Sleepy Cues to Watch
0-6 weeks
45-60 minutes
Looking away, yawning, red eyebrows
6-12 weeks
1-1.5 hours
Eye rubbing, decreased activity, fussing
3-4 months
1.5-2 hours
Pulling ears, jerky movements, crankiness
5-6 months
2-2.5 hours
Clinginess, less interest in play
7-9 months
2.5-3.5 hours
Slowing down, staring blankly, laying head down
10-12 months
3-4 hours
Rubbing face, stumbling, laying head on surfaces
These are guidelines, not clocks to stare at. Watch your baby, not the timer. Some babies show clear sleepy cues; others mask them. If you're consistently landing at one end of the range, that's your baby's window — trust it.
Day/Night Confusion (And How to Fix It)
Newborns don't have an established circadian rhythm. In the womb, they relied on maternal melatonin crossing the placenta and the rocking motion of your movement. After birth, it takes roughly 2-4 months for their internal clock to mature.
During those early weeks, many babies have their days and nights swapped — sleeping long stretches during the day and waking frequently at night. This isn't a sleep problem. It's biology catching up. But you can help speed the process.
Morning light. Get bright, natural light exposure within the first hour of waking. Take baby near a window or outside briefly. Light is the strongest cue for setting the circadian clock.
Daytime = bright and active. Keep the house well-lit. Don't tiptoe during naps. Normal household noise is fine.
Nighttime = dark and boring. Dim the lights after sunset. Keep night feedings quiet, in low light, with minimal stimulation. Change diapers only if soiled. Don't engage or play.
Light Sensitivity in Infants Is Extreme
Children's eyes transmit significantly more light to the retina than adult eyes. Research shows that blue-enriched LED lighting suppresses melatonin more in children than adults (PMID: 30556352). In preschoolers, even 5-40 lux of light in the hour before bedtime suppressed melatonin by 78% (PMC: PMC8933063). For context, 40 lux is a dim hallway light. Keep things genuinely dark at night — not just "dimmed."
Find their perfect bedtime
Use our interactive Sleep Calculator to find the research-backed sleep schedule for your baby's age.
Melatonin — the hormone that signals sleep — is suppressed by light. For infants, whose eyes are still developing and transmit more light to the retina, this effect is amplified. Use blackout curtains. Not "room-darkening" curtains — actual blackout. The goal is cave-dark for nighttime sleep and naps.
If you need a night light for nighttime feeds, use a dim red or amber light. Red wavelengths have the least impact on melatonin production.
Temperature
The ideal sleep temperature is 68-72°F (20-22°C). Overheating is a risk factor for SIDS. Dress baby in one layer more than what you'd wear comfortably. Feel the back of their neck or chest — not hands or feet, which are often cool — to check if they're too warm.
White Noise
In the womb, the constant sound of blood flow registers at roughly 80-90 decibels — as loud as a vacuum cleaner. After birth, total silence can actually be jarring. White noise helps by masking sudden sounds that trigger the startle reflex and providing continuous auditory input similar to the womb environment.
Keep volume under 50 decibels and place the machine at least 7 feet from baby's head
Use continuous sound (rain, fan, static) — not variable or musical sounds
Avoid playing white noise directly next to baby's ears, even with portable devices
Swaddling: Benefits and Risks
Swaddling can reduce the Moro (startle) reflex that wakes newborns. It's been used for centuries across cultures. But the research has nuances.
A meta-analysis by Pease et al. examined swaddling and SIDS risk across multiple studies (Pediatrics, 2016; PMID: 27244847). The findings: swaddling significantly increased SIDS risk when babies were placed on their stomach (prone), but showed no increased risk when placed on their back (supine). The key rules:
Always place swaddled babies on their back. This is non-negotiable.
Stop swaddling when baby shows signs of rolling — typically around 2-4 months, sometimes earlier. A swaddled baby who rolls to their stomach cannot use their arms to push up or reposition.
Allow hip flexion. The legs should be able to bend up and out. Tight wrapping of the legs increases the risk of hip dysplasia.
Breastfeeding and sleep are more connected than most parents realize. Beyond the well-established SIDS risk reduction, breast milk itself contains components that directly influence infant sleep.
Research by Cubero et al. found that breast milk follows a circadian rhythm — levels of tryptophan (the amino acid precursor to melatonin and serotonin) are significantly higher in nighttime breast milk than in daytime milk (PMID: 16380706). Nighttime breast milk also contains higher levels of melatonin and nucleotides that promote sleep.
What this means practically:
If you pump, consider labeling milk with the time it was expressed and feeding time-matched milk when possible (nighttime milk at night, daytime milk during the day)
Breastfed newborns typically wake more frequently than formula-fed newborns because breast milk is digested faster — this is normal and expected, not a sign of insufficient supply
The frequent waking for breastfeeding in early months may actually serve a protective function against SIDS by preventing excessively deep sleep
Sleep Regressions: What's Actually Happening
"Sleep regression" is a misnomer. What's actually happening is sleep progression — the brain is reorganizing, and the temporary disruption is a side effect of development. Regressions are predictable, temporary, and nothing you caused.
The 4-Month Sleep Regression
This is the big one, and unlike other regressions, it's permanent. Around 4 months, your baby's sleep architecture shifts from newborn-style (two stages: active and quiet) to adult-style (four stages, cycling through light sleep, deep sleep, and REM).
This means:
More partial awakenings between sleep cycles (every 45 minutes or so)
Increased awareness of their environment when they surface between cycles
If baby's sleep onset conditions have changed (the rocking stopped, the breast was removed), they notice — and they protest
The good news: this regression is the turning point. Once sleep architecture matures, you have an opportunity to build independent sleep skills. Put baby down drowsy but awake. Make the sleep environment consistent from bedtime through the night. This is when predictable routines start to really matter.
The 8-10 Month Sleep Regression
This one hits differently. It coincides with a cluster of developmental milestones: crawling, pulling to stand, and the emergence of separation anxiety. Babies who were sleeping well may suddenly wake at night and struggle at naptime.
You'll often see babies literally practicing their new motor skills in the crib — pulling to stand at 2 AM and then crying because they can't figure out how to sit back down. The fix isn't sleep training; it's motor practice during the day. Give them plenty of supervised time to practice standing and sitting during waking hours so their brain doesn't need to process it at night.
For the separation anxiety component: keep your response consistent and brief. Go in, reassure, leave. Don't introduce new sleep associations (rocking, feeding to sleep) that you'll then need to undo.
Behavioral Interventions: What the Research Actually Shows
The question of "should I sleep train?" generates more emotional debate than almost any other parenting topic. Let's look at what the research says.
A landmark randomized controlled trial by Gradisar et al. compared three groups: graduated extinction (timed checks), bedtime fading (a gentler approach that shifts bedtime later to build sleep pressure), and a control group (Pediatrics, 2016; PMID: 27221288).
Both intervention groups fell asleep significantly faster than controls. More importantly, the study measured salivary cortisol (stress hormone), parent-child attachment, and behavioral outcomes at 12 months post-intervention. The results:
No difference in cortisol levels between intervention and control groups at follow-up
No difference in parent-child attachment on standardized measures
No adverse emotional or behavioral effects at 12 months
Both graduated extinction and bedtime fading were effective. Graduated extinction produced faster results; bedtime fading was gentler but took longer.
When to Consider Sleep Training
Most pediatric sleep experts recommend waiting until at least 4-6 months. Before that, babies may not have the developmental capacity for self-soothing, and night feedings are still physiologically necessary.
Sleep training is a personal choice. It's not a requirement. Many families do well without it. But if sleep deprivation is affecting your ability to function safely or your mental health, the evidence supports that behavioral interventions are both effective and safe.
Common Methods
Graduated extinction (Ferber method): Put baby down awake, leave the room, return at increasing intervals to briefly reassure without picking up.
Bedtime fading: Temporarily push bedtime later until baby falls asleep quickly, then gradually move it earlier. Less crying but slower results.
Chair method: Sit in a chair next to the crib, moving it farther away each night. Good for parents who can't tolerate leaving the room.
Pick up/put down: Pick baby up when crying, put them down as soon as they're calm. Repeat. Works best for younger babies (4-6 months).
The "best" method is the one you can implement consistently. An inconsistent approach — starting a method then abandoning it mid-cry — teaches the baby that escalation works, which makes the next attempt harder.
SIDS Prevention: A Comprehensive Checklist
Sudden Infant Death Syndrome (SIDS) is the unexplained death of a seemingly healthy infant, usually during sleep. While the precise mechanism remains under investigation, the AAP's 2022 updated recommendations (PMID: 35726558) consolidate the evidence on risk reduction.
Back to sleep for every sleep
Supine (back) position for every sleep until baby can roll both ways independently. This alone reduces SIDS risk by more than 50%.
Firm, flat sleep surface
No soft mattresses, inclines, or padded positioners. Use only CPSC-compliant cribs, bassinets, or play yards with a fitted sheet.
Nothing in the crib
No blankets, pillows, bumpers, stuffed animals, or loose bedding. Use a wearable blanket (sleep sack) for warmth.
Room-share for at least 6 months
Baby's crib or bassinet in the parents' room. Same room, not same bed. This reduces SIDS risk by up to 50%.
Breastfeed if possible
Any amount of breastfeeding is associated with reduced SIDS risk. Exclusive breastfeeding provides the greatest protection.
Avoid all smoke exposure
Prenatal and postnatal smoke exposure are significant SIDS risk factors. No smoking anywhere near the baby.
Offer a pacifier at sleep time
After breastfeeding is established (3-4 weeks), offering a pacifier at naps and bedtime is associated with reduced SIDS risk.
Avoid overheating
Dress baby appropriately. No hats indoors. Room temperature 68-72°F (20-22°C). Feel the back of their neck to check.
Feeding and Sleep: Solid Foods, Timing, and the Evidence
You'll hear from well-meaning relatives that starting solids will help your baby "sleep through the night." The evidence is more nuanced than that.
The EAT (Enquiring About Tolerance) study — a large randomized controlled trial — found that early introduction of solid foods was associated with an average of 7 additional minutes of sleep per night and fewer nighttime wakings (PMID: 29987321). Seven minutes. Statistically significant in a large study, but not the miracle solution people expect.
The takeaway: introducing solids at the recommended 4-6 months (with pediatrician guidance) may modestly improve sleep, but it's not a fix for underlying sleep issues. If your 5-month-old is waking every 2 hours, rice cereal at dinner isn't the answer. Address sleep environment, wake windows, and sleep associations first.
Building a Bedtime Routine (Even for Newborns)
You can't "spoil" a newborn's sleep. But you can start building associations between certain activities and sleep from the earliest weeks. The routine doesn't need to be elaborate — 15-20 minutes is plenty.
Newborn Routine (0-3 Months)
Dim the lights
Diaper change
Swaddle (if still appropriate)
Feed
Brief snuggle or quiet song
Into the crib drowsy
At this age, "drowsy but awake" is aspirational. Some nights they'll fall asleep at the breast or bottle. That's fine. You're building a pattern, not enforcing a rule.
Older Infant Routine (4-12 Months)
Bath (the post-bath temperature drop promotes sleepiness)
Massage or lotion
Pajamas and sleep sack
Feed (ideally ending before baby is fully asleep)
Book or quiet song
Into the crib awake
The critical shift here: by 4+ months, aim for the last step to happen with baby awake in the crib. This teaches them that the crib is where sleep begins — not your arms, not the rocking chair. It's the single most impactful habit for long-term sleep independence.
When to Call the Pediatrician
Most infant sleep concerns fall within the range of normal. But contact your doctor if you notice:
Breathing irregularities: Persistent snoring, gasping, pauses in breathing, or noisy/labored breathing during sleep
Color changes: Blue, pale, or gray discoloration during sleep
Excessive lethargy: Unusually difficult to wake for feedings, not meeting feeding minimums
Failure to gain weight: If frequent night waking is paired with poor weight gain, there may be an underlying feeding issue
Your mental health: Severe sleep deprivation affects your ability to parent safely. If you're struggling, ask for help. This is not weakness — it's responsible parenting.
Trust Your Instincts
You know your baby better than any guide, any book, any well-meaning relative. If something feels wrong — even if you can't articulate what — call your pediatrician. They'd rather hear from you about nothing than not hear from you about something.
Want a printable version?
Download the free Sleep & Brain Development Checklist — a printable PDF with age-by-age sleep needs, safe sleep ABCs, wake windows by month, a bedtime routine template, and a 7-day sleep tracker. All backed by AAP guidelines and peer-reviewed research.
Newborns (0-3 months) need 14-17 hours of sleep per 24 hours, including naps. Sleep is fragmented, with stretches of 2-4 hours. Day/night confusion is normal in the first 6 weeks. By 6-12 weeks, you may see one longer stretch of 4-5 hours at night. Remember: newborn sleep cycles are 45-60 minutes (vs. 90 minutes for adults), so frequent wakings are biologically normal.
How much sleep does a 1-year-old need?
One-year-olds need 12-14 hours of total sleep per 24 hours. This typically includes 10-12 hours at night plus 2-3 hours of daytime naps (usually 2 naps transitioning to 1 nap around 12-18 months). A consistent bedtime routine, dark room, and age-appropriate wake windows (3-4 hours before bed) support quality sleep.
Why does my toddler wake up at night?
Toddlers wake at night for several reasons: developmental leaps (new skills disrupt sleep), separation anxiety (peaks 18-24 months), sleep associations (needing specific conditions to fall back asleep), overtiredness, undertiredness, illness, teething, nightmares, or environmental factors like room temperature. The solution depends on the cause—consistent routines, appropriate wake windows, and independent sleep skills help most toddlers.
Does screen time before bed affect sleep?
Yes, screens before bed significantly impact sleep quality. Blue light from screens suppresses melatonin production, delaying sleep onset. The stimulating content also keeps the brain alert. Research recommends no screens 1-2 hours before bedtime. If evening screens are unavoidable, use night mode (warm colors), keep brightness low, and choose calm content. Better alternatives: reading, puzzles, bath time, or quiet play.
What is Sleep Mastery: Infant about?
Sleep is the foundation of infant development. During the first year, your baby's brain is constructing the circadian system, consolidating memories, and processing the day's learning during sleep. This module provides the complete science of infant sleep: how it differs from adult sleep, realistic expectations at each age, the evidence behind safe sleep guidelines, the research on co-sleeping, and an objective look at sleep training methods. Master infant sleep with evidence, not anxiety.
What are the key points about infant sleep architecture & expectations?
How infant sleep fundamentally differs from adult sleep, why babies wake so often, and what research actually shows about normal sleep patterns at each age. Set expectations based on biology, not cultural myths.
Chemical messengers that transmit signals between neurons. Key neurotransmitters in child development include dopamine (reward and motivation), serotonin (mood and sleep), GABA (calming), and norepinephrine (alertness). Their balance affects behavior, learning, and emotional regulation.
A neurotransmitter that regulates mood, sleep, appetite, and digestion. Approximately 90% of serotonin is produced in the gut, highlighting the gut-brain connection. Low serotonin is associated with depression and anxiety. Sunlight exposure and exercise naturally boost serotonin.
A protein that supports neuron survival, growth, and the formation of new neural connections. Often called 'fertilizer for the brain,' BDNF levels are increased by exercise, learning, and omega-3 fatty acids, and decreased by chronic stress and poor sleep.
The ability to hold and manipulate information in mind over short periods. Working memory is essential for following instructions, mental math, reading comprehension, and problem-solving. It can be strengthened through practice and is affected by sleep and stress.
The rate at which the brain takes in information, makes sense of it, and responds. Processing speed affects academic performance, particularly timed tasks. It generally increases throughout childhood, peaks in early adulthood, and is supported by adequate sleep and myelination.
The length of time a person can concentrate on a task or stimulus without becoming distracted. Attention span naturally increases with age—roughly 2-3 minutes per year of age for focused tasks. It's affected by interest, sleep, screen habits, and environment.
This guide covers the essentials. The full Sleep Optimization module includes detailed protocols for every age, troubleshooting decision trees, environment optimization checklists, and the science behind every recommendation — from the first night home through the toddler years.
This guide covers the basics. The full Avaneuro program goes deeper with 40 modules, actionable checklists, and step-by-step protocols you can implement today.