4-Month Sleep Regression: Causes, Signs, & How to Get Through It
IN THIS ARTICLE
What Is 4-Month Sleep Regression?
What Causes 4-Month Sleep Regression?
Smart Sleep Coach
When Does Sleep Regression Start?
4-Month Sleep Regression Signs
How Long Does a 4-Month Sleep Regression Last?
If your little one was finally starting to sleep better and suddenly begins waking multiple times a night, taking short naps, or only sleeping in your arms, you're not alone. This sudden change is likely due to the 4-month sleep regression—a normal but frustrating part of infant development.
What is it?
The 4-month sleep regression is a natural shift in your baby’s sleep cycles as they mature, resulting in more frequent wake-ups and lighter sleep.
Why does it happen?
Common signs:
How long does it last? Usually 2–6 weeks, but it may take longer if sleep habits don’t adjust.
Keep reading for expert-backed tips and simple solutions to ease the 4-month sleep regression and help your baby (and you) sleep better—starting tonight.
What Is 4-Month Sleep Regression?
Just when it seemed like your little one had settled into a more predictable rhythm, you might notice your 4-month-old waking up more often at night or struggling to fall asleep again after waking. Suppose your baby’s healthcare provider has ruled out any medical concerns. In that case, there’s a good chance you’re facing the 4-month sleep regression, a common and temporary phase of disrupted sleep during early infancy.
So, what is a sleep regression? A sleep regression in babies occurs when a previously well-sleeping baby starts waking more frequently, has trouble settling down at bedtime, or requires extra help to get back to sleep. These changes in sleep can be linked to rapid development in your little one’s brain and body.
At around 4 months, one key developmental shift is the maturing of your baby’s sleep cycle. While newborns tend to drift in and out of short sleep intervals, four-month-olds' sleep schedules begin to follow more adult-like patterns, with lighter and deeper stages of sleep. That transition can lead to more frequent waking, especially if your baby hasn’t yet learned how to self-soothe, which is often at the heart of the infant sleep regression.
Do All Babies Experience a 4-Month Sleep Regression?
You may have heard a lot about the 4-month sleep regression, but not all babies go through it in the same way—or at all. So, do all babies go through sleep regression? Not necessarily. Some breeze through this stage with little disruption, while others may wake more often as their sleep patterns mature.
Tip
To help you deal with your little one’s sleep disruptions and keep track of their nap and sleep schedule, download the Smart Sleep Coach app by Pampers. Co-created by pediatricians and sleep experts, this app can help you establish a bedtime routine, support sleep training, and assist with managing sleep regression if it occurs.
What Causes 4-Month Sleep Regression?
Sleep regression can happen at various ages, but it's especially common around the 4-month mark, right when your baby’s sleep cycle is starting to mature. As your baby begins to understand the difference between night and day and their internal sleep rhythms become more organized, they may start sleeping longer stretches at night and taking fewer naps during the day.
Still, you might be left wondering: What causes 4-month sleep regression, and why does your little one suddenly seem so restless at night?
In Summary
If you’re wondering what causes the 4-month sleep regression, it often comes down to a mix of developmental changes, increased awareness, the maturing of the sleep cycle, and the fact that your baby may not yet know how to self-soothe. Other contributing factors, such as teething or inconsistent routines, may also play a role. While it can be exhausting, it’s typically a sign that your little one is learning and growing.
When Does Sleep Regression Start?
Now that we’ve established what sleep regressions are and what their causes may be, you might be asking, “When do babies go through sleep regression?” Many parents first notice changes in their child's sleep around 4 months of age. This is often when the 4-month sleep regression begins, as your little one’s sleep cycles mature and start to resemble adult-like patterns.
While research hasn’t shown sleep regressions to occur at a specific age for a baby, they may happen at different ages. The 4-month mark is a common time for disrupted sleep due to these biological and developmental changes.
4-Month Sleep Regression Signs
If your baby was sleeping more predictably and suddenly starts waking up more often, you may be spotting some common signs of a 4-month sleep regression. Around this age, your little one’s sleep matures, and temporary disruptions are common.
Here are some common signs of 4-month sleep regression:
If you’ve noticed some of these signs in your baby at 4 months or even older, your little one may be going through a period of sleep regression or 4-month sleep regression. However, your 4-month-old baby can wake up and have trouble sleeping for several reasons, including illness or teething. Contact your baby’s healthcare provider if you have any concerns.
Can the 4-Month Sleep Regression Affect Naps?
Absolutely. During the 4-month sleep regression, naps can become shorter, more irregular, or harder to settle into. So, if you're wondering, “Does sleep regression affect naps?”—yes, daytime sleep is often disrupted alongside nighttime wakeups. This shift is part of your baby’s maturing sleep cycle and usually improves as they adjust to new patterns.
How Long Does a 4-Month Sleep Regression Last?
When your baby’s sleep suddenly shifts, it can feel endless, but knowing that the 4-month sleep regression is a normal part of development may help ease some of the stress.
So, how long does a 4-month sleep regression last? It's likely that after a week or two, your baby will adjust to their new sleep cycle and start sleeping for longer stretches at night. At 8 to 9 months old, many babies will begin to sleep through the night. However, remember that every child is unique, and some may take more or less time to settle a consistent sleep pattern, while others may not experience a 4-month sleep regression at all.
So, while the 4-month-old sleep regression may feel like it drags on, know that it’s temporary. With time, consistency, and a little patience, most babies settle into more predictable sleep, just when it feels like you need it most.
Signs 4-Month Sleep Regression is Over
The 4-month sleep regression is a phase where your baby's sleep patterns may temporarily become disrupted due to developmental changes. While the exact duration varies for each infant, many parents observe that their baby's sleep begins to stabilize after a few weeks.
Some signs that the 4-month sleep regression may be ending include:
Tips: How to Deal With 4-Month Sleep Regression
If your baby is suddenly waking more often, resisting naps, or struggling to fall asleep, you might be searching for tips for 4-month sleep regression. The truth is, there's no one-size-fits-all solution—but there are supportive, gentle ways to help your baby (and you) get through this phase.
So, how do you deal with a 4-month sleep regression? It begins with consistency, patience, and minor adjustments that adopt healthy sleep habits.
Studies have shown that teaching and forming good sleep habits while your baby is young is easier compared to when they’re reaching toddlerhood. It just takes a little (or a lot) of time and patience—but better sleep is on the horizon!
Tip
As Mandy Treeby, Pediatric Sleep Coach and Co-founder of the Smart Sleep Coach by Pampers™ app, explains: “The act of falling asleep is a learned skill, and your baby needs the space and time to practice. Four months is the perfect time to start sleep coaching. By delivering consistent bedtime routines that always end with your baby drowsy but awake, you’re setting your baby up for sleep success from an early age!”
Whether you’re trying to figure out how to get through a 4-month sleep regression or just hoping for one decent nap, know this: You’re not alone, and this stage will pass.
Sleep Training a 4-Month-Old
By 4 months, many babies are ready to start learning how to fall asleep on their own. If you're exploring how to sleep train a 4-month-old, it's helpful to understand the different methods so you can choose one that feels right for both your baby and you.
Here are a few common approaches parents try when sleep training a 4-month-old, all of which vary in the level of parental involvement and comfort with crying:
Some babies may respond well to gradual reassurance, while others might find it more upsetting. It’s all about finding what works for your little one’s temperament—and your comfort. If you’re not sure how to begin or if sleep feels especially difficult, consult your baby’s healthcare provider for guidance before starting any method.
Can You Prevent 4-Month Sleep Regression?
Sleep regressions are a normal part of infant development, and not all babies experience them the same way. While you can’t fully prevent the 4-month sleep regression, building healthy sleep habits, such as a consistent routine and putting your baby down drowsy but awake, can make it easier to manage.
When to Consult Your Baby’s Healthcare Provider
Occasionally, sleep disruptions or a 4-month sleep regression may be caused by sleep disorders or certain illnesses. Contact your child’s healthcare provider if:
Self-Care Tips for Tired Parents
Sleep regressions can be exhausting for both you and your baby. While you're doing your best to support your little one, it's equally important to take care of yourself. These small, realistic steps can help you get through this tiring phase:
You’re not expected to do everything perfectly. Caring for your little one means caring for yourself, too. The more supported you feel, the more present you can be, one nap (or deep breath) at a time.
Not getting enough Zzzz’s?
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FAQS AT A GLANCE
Your baby’s sleep cycle is maturing, which may cause disrupted nights. This phase is commonly referred to as the 4-month sleep regression and can lead to frequent wake-ups or trouble settling down.
The Bottom Line
A newborn baby often comes with sleepless nights, but as your little one grows, they’ll likely start sleeping for longer stretches—and eventually through the night. Still, it’s not always a smooth transition. Around 4 months old, many babies experience the 4-month sleep regression, as their sleep cycle begins to mature, and they adjust to longer nighttime sleep periods.
While sleep regression can occur at any age, supporting your baby through this phase with healthy sleep habits, such as encouraging self-soothing, establishing a calming bedtime routine, and maintaining consistent sleep cues, can make a significant difference. With time, patience, and support, your baby will settle back into a better sleep rhythm—and you’ll get some rest, too.
Need a little extra support? Download the Pampers Rewards App to earn rewards on diapers and access educational content. Better sleep is ahead for both of you.
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