4-month sleep regression

The 4-month sleep regression is one of the first major challenges in a baby's daily life and often catches many families completely off guard. Between the 3rd and 5th month, your baby's sleep changes fundamentally: the previously simple sleep cycle becomes more complex and now resembles that of an adult. This means that more frequent nighttime awakenings, shorter daytime naps, and difficulty falling asleep are all perfectly normal.

Typical signs of 4-month sleep regression:

Frequent waking up at night (every 1-2 hours)
Longer periods of falling asleep, often accompanied by crying
Shortened naps (20–45 minutes)
More frequent nighttime feedings with breastfeeding or bottle
Practicing new skills (e.g., rolling over) in sleep
Increased restlessness or clinginess

Causes:

Transition from newborn sleep cycles to adult-like sleep cycles (5 phases, 90–120 min.)
Development of the circadian rhythm and melatonin
Cognitive and motor developmental leaps
Overstimulation from new impressions

How long does this phase last? This phase usually lasts 2 to 6 weeks and is a sign of progress, not regression. With patience, consistent routines, and loving support, you can get through this time together.

Below we show you how you can best support your baby during the 4-month sleep regression – with specific tips, strategies and a realistic view of baby sleep.

What is the 4-month sleep regression?

Just when it seemed your little one had settled into a better sleep rhythm, you might notice your 4-month-old waking up more frequently at night or having trouble falling back asleep after waking. If your baby's pediatrician hasn't found any underlying medical cause, chances are your little one is going through the 4-month sleep regression, a common and temporary phase of sleep disturbance in early childhood.

What is sleep regression? Sleep regression occurs when a previously sound-sleeping baby wakes up more frequently, has difficulty settling down, or needs extra help to fall back asleep. These changes in sleep patterns can be related to rapid development in your little one's brain and body.

Around four months of age, your baby's sleep patterns will begin to change. This change represents a significant developmental phase. While newborns tend to sleep in short intervals, four-month-old babies begin to follow more adult-like sleep patterns, with lighter and deeper sleep phases. This transition can lead to more frequent awakenings, especially if your baby hasn't yet learned to self-soothe, which is often a typical characteristic of 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. Do all babies go through a sleep regression? Not necessarily. Some children sleep almost undisturbed through the night, while others wake up more often during this phase because their sleep patterns are changing.

What causes 4-month sleep regression?

Sleep regressions can occur at various ages, but are particularly common around 4 months, precisely when your baby's sleep cycle begins to develop. Once your baby can distinguish between day and night and their sleep patterns become more regular, they often sleep longer at night and nap less during the day.

Nevertheless, you may be wondering what causes the 4-month sleep regression and why your little one is suddenly so restless at night.

Developmental changes. As mentioned earlier, babies' sleep cycles (circadian rhythms) begin to mature around 4 months, and they start adjusting their sleep patterns. This can temporarily disrupt their sleep and cause a 4-month sleep regression. However, think of it more as a learning curve than a "regression." Other developmental milestones and significant changes can also lead to a 4-month sleep regression, such as growth spurts , teething , and motor development —your little one is working hard!
The ability to self-soothe is not yet fully developed. All babies (and all older children and adults, too) wake up for short periods at night. A young baby needs time to learn how to self-soothe and fall back asleep independently.
Lack of a consistent routine. At this age, routines are very helpful. A regular relaxation period before bedtime helps babies learn that it's time to sleep. If you always give your baby a bottle to fall asleep or if bedtimes vary significantly, it can be difficult for them to fall asleep independently.
- However, if you develop the habit of rocking your baby to sleep in your arms or letting it fall asleep while feeding, this will become a routine every night and every time it wakes up in the middle of the night between sleep cycles.
Increased alertness and activity. At around 4 months, your baby begins to perceive their surroundings more intensely and shows more activity and independence. This increased alertness can make evening relaxation more difficult.
Possible medical causes. Sleep regressions in babies are often linked to a medical or health problem, such as a cold, ear infection , teething , or constipation . If your little one isn't sleeping well, watch for signs of illness .

Summary

If you're wondering what causes the 4-month sleep regression , it's often due to a combination of developmental changes, increased attention span, maturing sleep cycles, and the fact that your baby may not yet know how to self-soothe. Other factors, such as teething or inconsistent routines, can also play a role. While this phase can be tiring, it's generally a sign that your little one is learning and growing.

When does sleep regression begin?

Now that we've clarified what sleep regressions are and what can cause them, you might be wondering when babies experience a 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 follow more adult-like patterns.

Sleep regressions are not limited to a specific age and can occur in babies at various stages of life. The fourth month is a common time for disrupted sleep due to biological and developmental changes.

Signs of 4-month sleep regression

If your baby previously slept more regularly and suddenly wakes up more frequently, you may notice some common signs of a 4-month sleep regression. Around this age, your little one's sleep is maturing, so temporary disruptions are common.

Here are some common signs of 4-month sleep regression:

Long sleep onset times in the evening
Frequent waking up at night
Increased restlessness
Disrupted daytime naps

If your baby suddenly starts sleeping worse at 4 months or older, it could be due to sleep regression, which is common at this age. However, your 4-month-old baby could wake up and have trouble sleeping for a variety of reasons, including illness or teething. Contact your baby's doctor if you have any concerns.

Can the 4-month sleep regression also affect naps?

Yes. During the 4-month sleep regression, naps may be shorter, more irregular, or generally more difficult. Often, daytime sleep is disrupted in addition to nighttime sleep. This shift is part of your baby's maturing sleep cycle and usually improves as babies adjust to new patterns.

How long does a 4-month sleep regression last?

If your baby's sleep pattern suddenly changes, this period may seem endless. However, knowing that the 4-month sleep regression is a normal part of development can help alleviate some of the stress.

How long does a 4-month sleep regression last? It's likely that your baby will adjust to their new sleep cycle after a week or two and start sleeping longer at night. Many babies begin sleeping through the night by 8 to 9 months . However, keep in mind that every child is different, and some babies need more or less time to develop a consistent sleep pattern, while others may not experience a 4-month sleep regression at all.

Although the 4-month sleep regression can feel like an eternity, always remember that it's only temporary. With routine and a little patience, most babies eventually return to a more consistent sleep pattern, especially when you need it most.

Signs that the 4-month sleep regression is over

The 4-month sleep regression is a phase in which your baby's sleep patterns may be temporarily disrupted due to developmental changes. While the exact duration varies for each baby, many parents observe that their baby's sleep stabilizes after a few weeks.

Below are some signs that indicate the end of the 4-month sleep regression:

Longer sleep phases at night
More consistent naps during the day
Fewer awakenings during the night
Less help needed to fall asleep

Tips: How to deal with 4-month sleep regression

If your baby is suddenly waking up more frequently, refusing naps, or having trouble falling asleep at all, you might be looking for tips on 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) through this challenging phase.

What's the best way to deal with a 4-month sleep regression? It starts with routine, patience, and small adjustments that promote healthy sleep habits.

Encourage self-soothing. One of the most helpful tips for sleep regression is to give your baby the opportunity to fall asleep on their own. Instead of picking them up immediately when they cry, try waiting a moment before responding. This helps your baby begin self-soothing—such as sucking on their hand or being soothed by gentle movements—as they adjust to their changing sleep cycle.
Establish a bedtime routine . A consistent nighttime routine right before bed can help your baby relax and develop good habits for the future. Your bedtime routine could include a warm bath , a story , a lullaby , gentle rocking, a massage , or cuddles. During diaper changes, you can use Pampers Night Pants , which help keep your baby three times drier throughout the night, especially during the frequent waking phase.
Recognize the signals. Helping your baby fall asleep in their own bed teaches them to self-soothe without constant rocking. This small change in your behavior can make a big difference. Look for signs like eye rubbing, restlessness, or yawning to time it perfectly.
Feed your baby before bedtime. Your little one's body is growing rapidly, and hunger can contribute to nighttime awakenings. Offering a full meal right before bed can help them sleep through the night a little longer.
Maintain calm nights and active days. Another way to manage a 4-month sleep regression is to ensure calm nights – dim the lights, reduce stimulation, and speak in a soft voice. During the day, expose your baby to sunlight and let them play so they learn and understand the difference between day and night.

Developing good sleep habits early on pays off, according to studies. It's easier when the baby is still small than later in toddlerhood. It takes a little (or sometimes a lot) time and patience – but better sleep is on the horizon!

As Mandy Treeby , pediatric sleep trainer and co-founder of the Smart Sleep Coach by Pampers™ app, explains: “Falling asleep is a skill your baby needs to learn and practice. This requires space and time. Four months is the perfect time to start sleep training. By establishing consistent bedtime routines that always end with your baby sleepy but awake, you'll prepare your baby for healthy sleep from the very beginning!”

Whether you're trying to figure out the best way to get through a 4-month sleep regression, or you're just hoping for a decent midday nap from your little one, you should know that you're not alone and that this phase will also pass.

Sleep training for a four-month-old baby

At four months old, many babies are ready to learn to fall asleep independently. If you want to find out how to teach a four-month-old baby to sleep, it's important to know the different methods. This way, you can choose one that feels right for both you and your baby.

Here are some common approaches parents try when sleep-training a four-month-old baby . The methods differ in parental involvement and how to deal with the baby when it cries:

Sleep association . In this gentle method, the baby is placed in the crib while drowsy but still awake. If it cries, it is soothed every 5 to 10 minutes with words or a gentle touch, without picking it up. Over time, it begins to associate its bed with the comfort of falling asleep.
The Ferber method involves parents speaking soothingly to their child at regular intervals. It is also known as the interval method. Gradually, the intervals between these soothing sessions are lengthened to help the baby learn to self-soothe.
The cry-it-out method . Some parents put their baby in the crib and let it fall asleep alone – even if it cries. This method forgoes regular checks and isn't suitable for everyone, but some parents find it effective.

Some babies find gradual calming helpful, while for others it can be stressful. Find out what works best for your baby and your own well-being. If you're unsure how to start or your baby's sleep is proving challenging, it's best to speak with your pediatrician before trying any method.

Is it possible to prevent the 4-month sleep regression?

Sleep regressions are a normal part of childhood development, and not all babies experience them in the same way. While the 4-month sleep regression isn't entirely avoidable, it helps establish healthy sleep habits. A regular routine and putting the baby down when tired but still awake can make it easier to manage.

When should you consult a pediatrician?

Occasionally, sleep disturbances or a 4-month sleep regression can be caused by sleep disorders or certain illnesses. Contact your pediatrician if:

Your baby is particularly irritable and cannot be soothed. This could be due to colic , a common cause of sleep disturbances and restlessness.
You suspect that your baby's 4-month sleep regression is due to conditions such as an ear infection, reflux , or sleep apnea.
Your baby is having breathing difficulties.
You are having trouble waking your baby from sleep.

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 challenging phase:

Know your limits . If you feel exhausted, it's perfectly okay to ask for help or take a short break. Taking turns with a partner, friends, or family members – even if only for a short time – can help.
Rest whenever you can . Even a short nap or lying down while your little one sleeps can help you recharge your energy during the day.
Practice mindfulness. A few deep breaths, a quiet time, or a short break during a hectic day can help to bring your nervous system back into balance.
Be kind to yourself. This is a challenging time, and it's okay if your to-do list isn't completely checked off. Doing your best – whatever that looks like – is enough.

You don't have to do everything perfectly. Taking care of your little one also means taking care of yourself. When you feel supported, you can be much more relaxed and calm. Treat yourself to a nap or take a moment to breathe.

Frequently Asked Questions at a Glance

Your baby's sleep cycle is maturing, which can lead to disrupted nights. This phase is often referred to as the 4-month sleep regression and can result in frequent waking or difficulty falling asleep.

The 4-month sleep regression often lasts from a few days to about two weeks, depending on the baby. Once babies adapt to their new sleep patterns, their sleep usually improves.

Some common signs of 4-month sleep regression are:

Frequent waking up at night
Increased restlessness
Disrupted daytime naps
Long sleep onset times in the evening

Make sure that no other factors are disturbing your little one's sleep, such as teething, constipation, or illness.

If your baby is struggling with sleep regression at four months old, try establishing a calming bedtime routine, encourage self-soothing, and be consistent with sleep cues. Sleep regressions are temporary, and a structured routine can help your baby adjust more smoothly.

It's impossible to predict when or if your little one will experience a period of sleep regression. However, it usually occurs during various developmental growth spurts, such as around four months of age, because that's roughly when your baby's sleep cycle begins to develop.

Once the 4-month sleep regression is over, you may notice that your baby sleeps for longer periods at night or even sleeps through the night. If your baby wakes up at night, they can often soothe themselves and fall back asleep without your help.

If your baby is hungry, especially during a growth spurt, it's perfectly fine to feed them at night. Understand the signs they give you and consult your pediatrician if you're unsure.

Conclusion

Sleepless nights are often the norm in the first few months with a baby. But over time, your little one will sleep better and eventually sleep through the night. However, the transition isn't always smooth. Around four months, many babies experience the four-month sleep regression, as their sleep cycle begins to develop and they adjust to longer periods of sleep at night.

If your baby is experiencing a sleep regression, routines and patience will help. Support them by establishing consistent bedtimes and soothing rituals. With patience and support, your baby will soon sleep better again, and you can enjoy some rest too.

Need a little extra support? Download the Pampers Club app and collect points for diapers and exciting learning content. Better sleep for you and your baby is guaranteed.