Developmental Leaps and Milestones, How They Impact Your Baby's Sleep

April 18, 2023
 minutes read
Written by
Mandy Treeby
Chief Baby Sleep Consultant
Medically reviewed by
Elissa Gross, DO
Board Certified Pediatrician & Lactation Consultant

Your baby is growing so fast and learning new skills all the time – this is all very exciting for them, and you! But all these development leaps and milestones are strongly linked to sleep regressions, there are more than 20 such events in the first year of your baby’s life. Though completely normal, these temporary sleep setbacks can be a bit frustrating. To help you prepare, here we briefly outline the major developmental milestones your baby will experience and what to expect when it comes to your baby’s sleep.


Getting the help and guidance you need to confidently manage these sleep setbacks is really important. The Smart Sleep Coach by Pampers™ app combines expert sleep coaching with tools to help your baby get the sleep they need, so you stay in the driver’s seat when sleep gets off track.

What are Sleep Regressions?

Sleep regressions are brief moments when a baby that’s sleeping well will suddenly start waking up at night or having trouble falling asleep. These moments coincide with major developmental milestone – for that reason, we like to call sleep regressions sleep progressions – because they’re positive signs your baby is progressing well.

Why Do Developmental Leaps and Milestones Impact Sleep?

The fastest rate of brain development happens between 0 and age 3, most of this happens while your baby sleeps. As they grow physically and mentally, different aspects of their sleep are impacted in different ways. For example, sleep changes when their sleep cycles adjust and mature around 4-months , teething can be uncomfortable and wake them in the night, the ability to roll or stand are things that your baby may practice overnight and that too can disrupt their sleep, amongst other things such as object permanence.

Baby Development and Sleep Changes from 0-18 Months

Here we will cover some of the major developmental leaps and other events that may impact your baby’s sleep, by age. Remember every baby is different, not everything shared will impact every baby’s sleep – as always, if you have concerns about your baby’s sleep, reach out to their pediatrician.

0-3 Months Newborn

Newborns typically need 14-17 hours of sleep in a 24 hour period – and feeding still governs sleep, with the need to feed every 2-3 hours. Their average growth rate is 1-1.5 inches per month and weight gain is 1.5-2lbs in per month.

To support this period of rapid growth your baby may experience 3-5 growth spurts, sometimes wanting to feed every hour (often called cluster feeding). It’s not uncommon for babies who used to wake every 2-3 hours overnight to feed, to wake more frequently to feed. Go with it, they need this fuel to grow – it should correct within a week.

Other common sleep challenges amongst newborns are:

  • Resisting back sleeping (baby won’t settle on their back) – while they may seem more comfortable on their tummy, this is not safe (SIDS risk) and instead you can swaddle, offer a paci and be consistent and persistent. They will get there eventually.
  • Nocturnal sleep patterns – If your baby seems to sleep all day and party all night they may be mixing up night and day. Offer lots of daylight during the day, cap naps at 2-3 hours and make sure their sleep space is pitch dark for naps and overnight. It typically corrects within a couple of weeks.

At around 2-months your baby may be taking around 5 naps, that will transition to 4 naps by around 3 months, but it’s ok if your baby isn’t following a schedule like this

4-5 Month Old Babies

By 4 months most babies have doubled their birth weight their circadian rhythm) the internal system that regulates their sleep) starts to mature.

At 4-months old you will see more consistent sleep patterns and you want to transition from 4/5naps to a solid 3-nap schedule , ensuring your baby gets 12-16 hours of sleep in 24 hours, with 12 or so hours of that happening overnight.

Previously, your newborn’s sleep was very disorganized and would spend most of it in a deep, sleep – waking only briefly to feed and burp etc. However, when a baby nears 4 months, their sleep becomes both more organized in terms of time and closer resembles adult sleep. This development is at the core of the 4-month sleep regression , as your baby now fully wakes between sleep cycles and doesn’t know how to fall back to sleep without support.

Your 4-5 month old is now also infinitely more aware of their surroundings and it’s not uncommon for them to fight naps or bedtime out of pure FOMO.

6-7 Month Old Babies

By six months , your baby’s personality is really starting to come to life, they may have started teething and beginning to find their voice. At the same time their eyesight is improving, color recognition sharpens around now, too – and your baby’s is fine tuning their motor skills as they attempt to grab toys and put objects in their mouth.

Physically, your baby is getting much stronger, likely rolling over both ways and may be able to sit up, perhaps even starting to crawl. They recognize you when you enter the room and are able to gesture for things they may want and even play games like peek-a-boo.

While there isn’t a specific 6-month sleep regression, many babies also go through a growth spurt at 6-months. Coupled with this rapid physical and mental development and compounded by teething, all of these things can have an impact on your baby’s sleep and babies who previously slept through the night may start to wake from teething discomfort or to feed, fight naps and bedtime can become more challenging.

8-10 Month Old Babies

Your 8-month-old baby is gaining more physical abilities, like learning to crawl and most 8-month-olds are also beginning to understand object permanence – a big milestone that can cause some new sleep challenges.

Object permanence is the realization that objects and people continue to exist even when you can't see them. Before this moment, your baby was very much “in sight, in mind” – when you left the room, they would start to focus on other things. Now, though, babies learn that when you or someone else leave the room, you haven’t disappeared – you’ve gone somewhere else. They want to know where you’ve gone.

This is at the center of the 8-month sleep regression and generally, the best way to overcome separation anxiety sleep problems is to stick to your schedule, keep your bedtime routine , and offer additional reassurances before bed. With a little patience and by sticking to your sleep plan, your baby will overcome this sleep regression in no time.

Note: Babies who are sleep trained, often overcome sleep regressions faster because sleep they have already learned how to self-soothe.

8 months is also when your baby will transition from 3 to 2 naps, as you drop that last nap of the day it can help to transition bedtime earlier.

11-14 Month Old Babies

Whoa! Your baby is a real mover and shaker by 11months they are most likely crawling possibly cruising around furniture, and by around 12 months, if they haven’t already taken those incredible first steps, they will soon. This subconscious knowledge can inspire babies to stay up at night practicing standing and moving their little legs – in other words, a perfect sleep progression. The ability to stand and pull up on the crib can also pull at parents heart strings if their baby is protesting bedtime or waking up in the middle of the night – and many parents report sleep set backs around this age.

Somewhere between 15 and 18 months your baby to transition from two naps to 1 nap, this is one of the tougher transitions as it is more of a consolidation of the morning and afternoon nap into one long lunchtime nap. It can take a few weeks for your baby to settle into their new routine.

As your baby nears 18 months, your walking, talking toddler is also developing a growing sense of independence. They want to do more things on their own and is starting to test boundaries with their new favorite word, "No!"

This increasing self-confidence is amazing as you watch your baby try new things and take more interest in grown-up activities, like helping put away groceries. However, it also means you'll likely be facing more battles at naptime and bedtime.

The above information is a truncated review of the many developmental milestones your baby will accomplish over the next few years. For more information on developmental milestones by month, read our pieces for each individual month.

How to Cope with Sleep Regressions, Growth Spurts and Sleep Setbacks

With more than 20 different events that can cause sleep setbacks in the first 18 months of your baby’s life, Mandy Treeby , Pediatric Sleep Coach and Co-Founder of the Smart Sleep Coach by Pampers offers her top tips for getting through these regressions quickly:

  • Deliver a consistent bedtime and nap time routine that always ends with your baby drowsy, but awake – the act of falling asleep needs to be done by your baby
  • Follow an age appropriate nap schedule, with the day starting between 6-7am (when your baby’s circadian rhythm resets each day).
  • Don’t push wake windows, use sleepy cues
  • Use an earlier bedtime when naps don’t go well
  • For babies struggling with separation, offer additional reassurance at bedtime
  • Be careful not to introduce new sleep crutches, 4-months old is a good time to consider sleep training if you haven’t started already.

Learn more on how to cope with sleep regressions

For older babies, where behavior can come into play and verbal protests can make a baby’s sleep resistance a bit more frustrating, when your baby says “no” to bed, Mandy suggests:

  • Involving them in their bedtime routine: Distract your baby’s protest by asking them to pick their bedtime story and pajamas – often this added responsibility will help them feel like they have more agency over the process. Don’t give too much choice though, that can result in a different problem, but letting them pick between the orange and the green PJs can work wonders!
  • Be firm, But Kind: It’s hard to say “no” to your baby sometimes, but try to stay strong when it comes to bedtime protests. Do not let your baby stay up “just this once” because that can set a precedent. Remember you have met all of their needs, this is about responding to their wants.

Step-by-Step Gentle Sleep Training

Few Parents Know, falling Asleep is a learned skill. Just like rolling, crawling, walking and talking – babies need help to master sleep.


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Studies show new parents can lose as much as two hours of sleep every night after their baby comes!

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Developmental milestones can lead to temporary sleep disruptions, yes – and this is completely natural. Luckily there are many reliable ways to help your baby sleep during developmental milestones.

A baby’s circadian rhythm begins to develop around 4-months, which is why that’s the best time to start sleep coaching. While a baby’s sleep will become more organized without sleep coaching, they will still struggle to fall asleep, stay asleep, or maintain a consistent sleep schedule during developmental leaps.

While babies who sleep train are not necessarily smarter, studies do show that babies who get age-appropriate sleep have stronger linguistic, learning, emotional, and cognitive skills. Sleep is just as important as nutrition in terms of its positive impact on babies’ long-term health.

Sleep regressions are brief blips in your baby’s sleep training journey. Once a sleep regression is handled or minimized, your baby’s sleep schedule will normalize, and they’ll be back to sleeping through the night – especially if they’ve been sleep trained.

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How We Wrote This Article

The information in this article is based on the expert advice found in trusted medical and government sources, such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists. You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.


“Your Baby's Hearing and Communicative Development Checklist,” National Institute on Deafness .

“Normal sleep patterns in infants and children: a systematic review of observational studies,” Sleep Medicine Review.

“Infant developmental milestones and subsequent cognitive function,” Annals of Neurology .

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