A Simple Guide To Your Baby's 4-Month Sleep Regression

Updated Jun 15th 2022 | timer 8  min read

What is the 4-month sleep regression, why it happens
Elissa Gross

Medically Reviewed By medical-check-mark Elissa Gross Board Certified Pediatrician & Lactation Consultant

Mandy Treeby

Written By Mandy Treeby Chief Baby Sleep Consultant

Watching your baby grow is one of life's greatest blessings. Being the parent of a new baby is beautiful and exhilarating — but also exhausting! It's no secret that having a baby turns your sleep routines upside down. Twilight feedings and cuddles are just a way of life for new parents, but it doesn’t have to be that way.


Having the confidence and skills to guide your baby sleep to a routine that works may seem an impossible task, but it’s actually easier than you think. Simply having the knowledge and understanding of what is happening and learning how to communicate desired sleep behaviors can work wonders. That’s why we love the  Smart Sleep Coach by Pampers™ app, it combines expert sleep coaching with in-app tools that work with you, at your pace, to get your baby’s sleep on track, so even when regressions happen – you have the experience to get things back to normal, fast.

Newborns sleep a lot, but it's broken up into small fragments throughout the day and night. They may wake frequently for night feedings and nap often during the day. As a newborn, your baby may have woken up frequently at all hours of the night, leaving you bleary-eyed when the sun came up. But after a while, your baby may have started to sleep for longer stretches — giving you some much-needed rest, too.

Then just when it seems you have your baby's sleep schedule figured out, he starts waking up at night again. Could this be the 4-month sleep regression you've heard about? What exactly causes sleep regression? How long does sleep regression last, and how do you cope with it?

As a parent, it's hard to function when your four-month-old is not sleeping. Yet, it's common for babies to start waking up at night around this age. You're definitely not alone! What's more, sleep regression is actually an important developmental milestone for your baby.

What is the 4-Month Sleep Regression?

A sleep regression is when your baby starts waking up at night, after a time period of sleeping more predictably. From the outside, this may seem like he's "regressing" on the progress he's made adapting to longer sleep intervals.

However, sleep regressions actually happen because your baby is maturing, not backsliding. A sleep regression often first appears around three to four months old, although every baby is different. Sleep regressions are a normal part of a baby's first year. And don't worry, it won't last forever!

If this regression is causing major sleep disruption, getting expert help doesn’t have to break the bank. Apps like the Smart Sleep Coach by Pampers™ offer affordable subscription based programs that combine expert sleep coaching with in-app tools to help you confidently navigate this regression and other sleep setbacks when they happen.

Signs of the 4-Month Sleep Regression

How do you know if your baby is going through a sleep regression?

  • Your four-month-old starts waking up at night.
  • Your four-month-old is waking up every hour or two hours.
  • Your four-month-old starts waking for feeds again.
  • Your baby has a harder time falling asleep.
  • Your baby may be fussier when he wakes up.
  • He may sleep for a shorter length of time overall.
  • Your four-month-old is waking up crying.

Sleep regression can happen alongside other milestones and changes. As your baby is hard at work taking in the world around him or learning new skills, a sleep regression may also be approaching.

What Causes Sleep Regression in Babies?

Sleep regressions can happen because of biological changes your growing baby goes through. You may have heard of the circadian rhythm. It's basically your body's natural 24-hour cycle, including the sleep-wake cycle. As a newborn, your baby's sleep isn't governed by circadian rhythms like an adult's. That is — not yet.

Your newborn baby is still developing in countless ways. He doesn't mature into his circadian rhythm after birth. So at first, newborns sleep about 70% of the time. But this sleep is divided up into short intervals throughout the day and night. Newborns wake frequently for night feedings and  nap often during the day.

It's not until three to four months that babies begin shifting into a more adult pattern of wakefulness during the day and greater sleep at night.

When your little one gets to be around this age, their sleep advances into cycles of light and deep sleep, closer to that of an adult's. In fact, your baby begins going through five sleep cycles, instead of the same sleepy state as when he was a newborn. This is a good thing—It means your baby is undergoing healthy development.

But these changes in sleep cycles mean your baby might start waking up more often, and you with him. Why might this change result in frequent night wakings, anyway?

More info about sleep regression causes

Big Changes for Baby

As adults, we constantly alternate between four stages that range from light to deep sleep throughout the night. Until a baby is about three months of age, he spends his sleepy time in two sleep stages . Then, babies begin to go through four sleep stages once they're a few months old.

As an adult, you’ve fully adjusted to these sleep cycles and likely don't even realize you're going through them. But your baby is just learning to go through more complex sleep cycles. If your baby becomes woken during a lighter sleep cycle, he may have trouble getting right back to sleep, especially if he wakes up in a different place than where he fell asleep. So don't be alarmed if your four-month-old is waking up at 4 a.m. or 5 a.m. and doesn't go back to sleep as easily.

Not only that, but at three to four months of age, your baby is conquering a lot more milestones than just sleep cycles!

He may be starting to teethe, rollover, or be going through a big growth spurt around this time. Research has shown that sleep disruptions can occur when your baby is going through milestones , like advances in motor development. So if your baby is showing some big changes around three to four months, it could also play into his 4-month sleep regression.

Baby undergoes lots of growth and motor skills in the first year of life. So while it's hard to go through as a tired parent, it's not surprising that babies naturally go through periods of disrupted sleep.

How Long Will the 4-Month Sleep Regression Last?

Every baby is unique. But for many babies, sleep regressions can last up to several weeks, though it may be much shorter. Some babies may not even go through a noticeable sleep regression. Your baby could also have sleep regressions that come and go at various times during his first year.

Have no fear — sleep regression doesn't last forever. But this doesn't mean it's not a challenge for parents. Whether this is your first baby or you have other children at home, frequent nighttime wakings aren't fun. If your four-month-old is not sleeping, what are some ways for you and Baby to get through it?

Survival Tips for the 4 Month Sleep Regression

If you're going through a 4-month sleep regression with your baby, you’re not alone!

Coping with sleep regression is a normal part of parenthood, and also a temporary state. With a few easy strategies, you can help your baby get through the regression and support him on his path to more mature sleep. The upside of sleep regression is your baby may start sleeping for longer intervals at night, once he gets through the regression.

We asked our Smart Sleep Coach by Pampers™ experts to share what they recommend to help establish healthy sleep habits for your baby and cope with sleep regressions:

Adopt a Healthy Bedtime Routine

It’s important to establish a stable routine to promote good sleep habits. Through a calming, peaceful atmosphere and consistent bedtimes, you'll help your child settle into sleep more easily. Whether or not your child is going through a sleep regression, a routine will help them feel safe and secure knowing what to expect each evening. A bedtime routine could include things like feeding, a warm bath, reading books together, applying lotion, giving an infant massage, and putting him to sleep in the same place each night.

Keep a Dark Sleep Environment

Natural light and dark cycles help your baby know when it’s time to sleep or wake up. Keeping the room dark at night will help your baby start recognizing when it’s time for sleep. If they wake up during the night, the dark environment will help them fall back asleep.

Give Baby the Chance to Practice Sleeping on His Own

It may be tempting to always pick up your baby, rock him, or cuddle him when he is sleepy. There's nothing wrong with giving him as many cuddles as he needs, but it can be helpful to let your baby try falling asleep on his own.

If your baby wakes up at night, don't talk or play. Instead, try to take care of his needs calmly and quietly and get him back to bed quickly. It's also helpful to put your baby down when he's drowsy instead of fully asleep, so he can get used to falling asleep on his own.

Ensure Baby Is Well-Fed Throughout the Day and Before Bedtime

Your baby is growing rapidly before your eyes — he needs lots of nutrition to fuel all those big changes! A hungry belly could leave your baby wakeful and fussy during the night. Try feeding Baby in a quiet place during the day so he'll have fewer distractions from eating. Then, feed him right before bed so he'll be less likely to wake up hungry at 4 a.m.

Be Gentle With Yourself

Being a parent is powerfully rewarding. But it's not an easy job. Don't forget to be patient with yourself as much as your baby as new challenges arise. With growth comes change. And it's a learning curve for both of you!

Going through a 4-month sleep regression can be difficult. But armed with knowledge and a few helpful strategies, you can survive it. Rest assured, a 4-month sleep regression is a normal part of your  baby's development that will come and go. As always, if you have any concerns about your child's sleep patterns or overall health, talk to your pediatrician.

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