Updated on
November 29, 2024
It’s 6 a.m., and the day is just starting. Your baby’s sweet little face lights up, ready to take on the world with you. You lift them out of bed, and the first wake window begins. After some snuggles, you ease into the morning: brushing teeth, having breakfast, and playing. Just as you take a bite of your last piece of toast, your baby starts showing the first signs of sleepiness—yawning, rubbing their little eyes, and getting fussy. "Tired already?" you wonder. "Didn't they just wake up?" You glance at the clock—1.5 hours have already passed. Time flies when you're having fun!
You scoop up your baby and rush to the bedroom, pull the curtains, and start singing “Twinkle, Twinkle, Little Star” – but it’s too late! Your baby is tense, clenching their little fists – the first signs of being overtired. You’ve missed the “sleep window” again. But don’t worry, you’re not alone.
If helping your baby sleep feels like a challenge and you’re new to wake windows, or the idea of a “sleep window” leaves you with more questions than answers, you’re in the right place! Learn what wake windows are, why age-appropriate wake phases are key to your baby’s development, and how to use them to help your baby sleep better.
Curious? Stick around!
So, your baby is between three and four months old (or older) and suddenly doesn’t want to sleep anymore? No wonder you’re concerned! Don’t blame yourself; it’s not your fault. The reasons for this challenging sleep behavior are biological—and completely NORMAL. Spoiler alert: Along with learning many new cognitive and motor skills, your baby is also learning how to sleep.
How does all of this connect? What do growth and developmental spurts have to do with it? And why shouldn’t you fear the infamous 4-month sleep regression? You’ll find out next.
Below, we answer the most common questions about the 4-month sleep regression:
Sleep, eat, repeat. That pretty much sums up life for new parents, right? But wake windows are just as important as feeding and naps. Wait—what exactly is a wake window?
A wake window is the period between your baby’s sleep cycles. In other words, it’s the time your baby is awake—between one nap and the next—when they can comfortably stay up without getting overtired.
Wake windows include everything that happens outside your baby’s usual sleep environment—whether they’re in their crib, bassinet, or baby carrier. Feeding, going for walks, playing—and even the routine before nap time or bedtime—are all part of your baby’s wake window.
The length of your baby’s wake window depends on several factors, especially their age. As your baby grows, they’ll be able to stay awake for longer stretches. But more on that in just a moment!
That’s really a matter of perspective. For us, a baby’s wake window doesn’t start with the first blink of their eyes but when you take them out of their sleep environment - whether it’s the family bed, crib, bassinet in the kitchen, or your baby’s favorite, the carrier.
In turn, a wake window ends as soon as you place your baby back in their familiar sleep area.
Is your baby fidgeting or babbling when you lay them down? Totally normal. On average, babies take 5-20 minutes to fall asleep, while toddlers may take up to 30 minutes - wiggling, babbling, and all. But this time is already part of their wind-down routine, not the wake window.
Why? Right before your baby falls asleep or wakes up, their brain is in a rest state - a special sleep-wake transition—and guess what? Yours is too! This phase is no longer considered part of the wake window.
Generally speaking, the younger your baby is, the shorter their wake windows and the higher their overall sleep needs. As your baby grows, their wake windows naturally lengthen, and they start needing fewer naps throughout the day.
Contrary to popular belief, “the longer your baby stays awake, the better they’ll sleep at night” is just not true. In fact, it’s quite the opposite. Newborns and younger babies need plenty of daytime sleep. Getting enough rest helps support their physical growth and development and prevents them from becoming overtired and fussy in the evenings.
For example, newborn wake windows range from just 30 to 90 minutes, which is why they need lots of short naps, especially in the first three months. Babies between 6 and 8 months old can handle being awake for up to 3.5 hours and usually need only 2 or 3 naps each day. By 12 months, most little ones have dropped down to just 1 or 2 naps a day.
As a helpful guide, we've created a table for you showing typical wake windows based on age:
Finding the perfect wake window for your baby or toddler can be quite a challenge. You’re probably wondering how you’ll know if you’re on the right track, right?
Here’s the answer: when naps and bedtime go smoothly, and after just 10 minutes, you can sneak out of the bedroom with a smile on your face.
Many parents would probably describe a newborn's sleep-wake pattern as completely unpredictable. Set nap times? A routine? Planning anything? No way! Those things are on hold - at least for now. At this stage, there’s just no consistent sleep pattern (Developing a day-night rhythm: How your baby's sleep evolves). When your newborn falls asleep, and for how long, can be as random as it gets. Some babies take quick 10-minute power naps, others might sleep for up to 4 hours straight. And some might even decide to turn night into day!
But don’t stress - your newborn isn’t trying to make things difficult! The reason behind their seemingly chaotic sleep pattern is an immature day-night rhythm, which starts to mature when your baby is around 4 months old. Until then, their internal clock, called the circadian rhythm, which helps regulate sleep, is still getting into gear.
During the day, newborns should sleep a lot—about 16 to 18 hours in a 24-hour period - and can usually only stay awake for 35 minutes (in the first 4 weeks) to 90 minutes (by 4-12 weeks) at a time.
Around the fourth month, many babies experience the 4 month sleep regression, which can completely shake up your baby’s sleep routine - and yours! What’s happening? Your baby is now starting to produce enough melatonin to regulate their day-night rhythm. This is the perfect time to introduce consistent bedtimes and a solid sleep routine for both day and night.
Your baby’s sleep cycles are also getting longer, meaning they can start sleeping for several hours in a row at night. Plus, your baby’s wake windows are stretching too - they can now stay awake for 2 to 3 hours without a problem.
By now, your baby’s sleep-wake rhythm has become more stable, sleep cycles have lengthened, and the days and nights may feel a bit less chaotic - at least for some parents! If you’re not one of them, don’t worry, that’s also totally normal. You’ll get there eventually.
At this age, babies can sleep up to 11 hours at night, with 2 to 3 naps during the day, and they’re able to stay awake for about 3 to 4 hours between naps. Around 8 months, many babies go through a big developmental leap, mastering new skills like sitting, crawling, and babbling. These milestones can temporarily disrupt their sleep, a phase often referred to as the 8-month sleep regression. During this time, many babies transition from 3 naps to 2 per day.
At this age, most babies can theoretically sleep for several hours at a time without needing help from mom or dad at night - unless they’re dealing with teething pain, nightmares, or separation anxiety. Then, your baby will need some additional TLC.
By 12 months, babies and toddlers typically settle into 1-2 predictable naps a day, making it much easier for you to plan your day around their schedule.
A great question! Wake windows are super important because they not only determine how many naps your baby or toddler needs throughout the day but also influence how smoothly they fall asleep and stay asleep at night.
During each wake window, your baby builds up what's called "sleep pressure" - basically, the body’s growing need for sleep. This pressure gets relieved during naps and starts building up again once your baby is awake.
So, what does this mean in real life?
If your baby’s wake window is too long, they can become overtired and struggle to wind down before bedtime. This can lead to more restless sleep at night and earlier wake-ups. On the flip side, if the wake windows are too short, your baby might refuse to sleep because they’re just not tired enough yet.
The goal is to find the right wake window for your baby - it might seem tricky, but it’s definitely doable! How? I'll walk you through it in the next section.
Do you want to support your baby and learn more about their sleep patterns? Happy Baby creates a daily sleep schedule tailored specifically to your child’s age and current needs.
"Trial and error" definitely applies when it comes to finding the right wake windows for your baby. As you’ve probably noticed, it’s not always easy to nail down the perfect timing. But you’ll know you’re on the right track when naptime and bedtime go smoothly - yes, it’s possible.
So, how do you find the ideal wake window for your baby?
a) By closely observing your baby’s behavior and getting a feel for their sleep cues.
b) By keeping age-appropriate wake windows in mind.
As you near the end of a wake window, look for common signs of tiredness [Link] to avoid your baby becoming overtired:
If you answered "yes" to these, it’s a good sign that your baby is getting sleepy and ready for bed. If the sleep pressure isn’t quite there yet, your baby will let you know - maybe even by happily crawling right back out of the bedroom! In that case, let them play for another 10 minutes, then try again.
Knowing how long your baby can stay awake without any issues helps you better gauge their optimal wake window. Age-appropriate wake windows are helpful guidelines recommended by sleep experts, but they’re not set in stone. Every baby is unique, and their sleep needs will vary. Don’t stress—you’ve got this!
Sleep regressions are phases in which baby's and toddler's sleep pattern can temporarily change due to growth spurts. This is a normal part of child development and often occurs around four, eight, twelve, 18, and 24 months of age. During these phases, babies and toddlers may have difficulty falling asleep and sleep poorly - at night as well as during the day. Fortunately, sleep regressions are not permanent; after a developmental leap, your child's sleep should return to normal. Parents can help their child navigate a sleep regression with a personalized sleep plan, along with consistent routines and rituals.
Are you unsure whether your baby has sleep regression and would like to understand your baby's sleep patterns? With Happy Baby, you can record your baby's sleep and create an individual sleep plan that helps you through the difficult phases.