4 month sleep regression

4 Month Sleep Regression: Everything You Need to Know

You breathe a sigh of relief. Your little one is FINALLY sleeping through the night after weeks and weeks of getting up every couple of hours. You are excited to get in some zzz’s of your own. Then, the 4 month sleep regression hits. 

While the 4 month sleep regression doesn’t happen for all babies, it can be frustrating as a new parent when it happens with yours. Here is a look into what this new phase is all about and some insight into getting your little ones sleeping back on track. 

The 4 Stages of Sleep 

The body has a four-stage sleep cycle that your brain switches between as the night progresses. These four stages ensure that you get enough sleep, so your body is at optimal function during the day. 

Quality sleep is crucial for babies since they are continually growing and building new muscle structures. Your little one’s sleep affects every portion of their body, including their heart, brain, lungs, and metabolism. It even has a bearing on your child’s immune system and their mood. 

As growing babies, all these areas must function as they are intended to. Sleep is broken into two main types of sleep, rapid eye movement (REM) or non-REM sleep. 

Stage 1

In this first cycle of sleep, your mind adjusts from being awake into sleep. This cycle is very short, typically only lasting a few minutes. This is considered a light sleep, allowing your little one’s body to slow down. Everything from their heartbeat to breathing, eye-movements, and muscles relax so they can move into their next sleep cycle. Their brain pattern also switches from daytime to nighttime waves. 

Stage 2

In stage 2, your baby transitions to the next non-rem segway to a deeper slumber. Your baby’s entire body continues to slow down. Eye movements will stop, and their body’s core temperature drops. Noteworthy occurrences for this stage are short spurts of electrical activity in the brain. 

Stage 3

Sleep in stage 3 is what gives people that ready to go feeling in the mornings. The feeling you get when you know you have slept well. For your baby, great sleep in this stage sets them up for a happy, fun day. 

Stage 3 sleep generally happens earlier during sleep. At this point, all of your baby’s general functions slow to their lowest levels. The body becomes fully relaxed, and it is difficult to become stirred awake. 


Generally, REM sleep happens within 90 minutes of falling asleep. In this stage: 

  • Eyes will move rapidly
  • Brain waves are closer to awake levels
  • Breathing is fast and irregular
  • Heart rate increases
  • Blood pressure increases 

Dreams happen most often in REM sleep, though some dreams may occur outside of REM. The body is paralyzed in this state to prevent the body from physically acting out the dreams as they are happening. 

What is the 4-month sleep regression?

According to the Sleep Foundation, the 4-month sleep regression happens because your child’s brain chemistry begins to change. Since they are developing quickly, the changes within their brains and nervous systems can result in instability in their sleep. 

At this point, they also are able to produce melatonin. With adequate melatonin levels in their systems, babies can begin the transition to a 24-hour cycle. This moves your baby’s sleep patterns closer to that of your own. They begin to develop their circadian rhythm. 

When does the 4-month sleep regression start?

The move away from newborn sleep is generally the trigger for the beginning of the sleep regression. Their newly developed circadian rhythm can set off a chain reaction of new cycles. The transition between cycles is not as smooth for them as it is for adults since it is new. 

Because of this, babies can wake between the cycles. If something in their environment changes, such as their location, temperature, or even the lighting, it can be enough to startle them awake. 

Depending on your child, this transition can begin a little before 4 months, or it may wait until they are older, for example, around the 5 or 6-month mark. 

Look for signs from your baby. Obviously, the primary signal is that their sleep patterns suddenly and dramatically change. However, there are some other warning signs of an impending sleep regression, which are:

  • General fussiness
  • Waking multiple times a night
  • Fewer naps
  • Appetite changes

All of these signs can give you an insight into what is going on with your little one. Even though sleep regressions can be frustrating, they are a sign that your baby is growing, which is always a good thing. 

How long does the 4-month sleep regression typically last?

Your child’s sleep regression may have you wondering at what age does sleep regression stop? Sleep regressions typically last only a couple of weeks. Though it does signal a permanent change in their sleeping habits.

However, sleep regressions can happen at any age. Even a 12 or 18-month-old can have a sleep regression. Each time a regression happens, it can last up to four or so weeks. Every baby is different. The best you can do is put systems in place to manage the sleep regressions as they come and for however long they end up staying. 

Managing the 4-month sleep regression

It can be challenging to know how to deal with your child’s sleep regression. Part of that can be attributed to not having enough sleep yourself and your brain not piecing information together as well as it used to. However, there are a few steps you can take to manage your baby’s sleep cycle and bring their sleepless nights to an end. 

Learn How Much Sleep Your Baby Needs 

As your baby grows and their brains begin to change, their sleep patterns and needs change too. Newborns typically sleep between 14-17 hours of sleep each day. This sleep is generally distributed in 1-3 hour spurts throughout the day and lasts until about 2 months. 

After the two month mark, a baby’s sleep pattern will shift. As the 4-month sleep schedule changes, so do your babies’ need for sleep. Babies will still take multiple naps throughout the day. But they will begin to be awake longer in between and will shoot closer to 14-15 hours of sleep a day. 

Feed as Much as Needed During the Day

At this age baby’s are far more involved in their surroundings. They can see further away and more clearly. Because of this, they can become easily distracted. Make sure they get enough food throughout the day by: 

  • Feeding in a neutral environment
  • Eliminating external distractions
  • Try not to add in additional feedings at night
  • Ensure they are full before you end their feedings

Going to bed on a full tummy will help them to sleep more soundly. It also adds one less factor for waking as your child switches between cycles. 

Set Up The Nursery For Success 

A big part of adapting to sleep regressions is ensuring that the nursery is a soothing environment. Since the 4-month sleep regression can be attributed to many different factors. In fact, pediatricians have not pinpointed just one cause for the 4-month sleep regression. 

To cover all your bases, you may want to adjust a few things in your nursery to create a better environment for sleep. 

If you do not already have a set, some blackout curtains will help keep the light out of your child’s room. It can set the proper tone during nap time, signaling to your child that it is time to sleep. The light streaming in through their windows can be very disruptive to their sleep, especially if they are in a light sleep cycle and it jolts them awake. 

Noise around the house can also be a factor, especially if you live in an apartment or condo. If your little one has trouble sleeping due to noises, try adding a sound machine to their room. 

Sound machines can be very soothing. They have many different settings that range from classical music to ambient noise. Finding an environment that keeps your child relaxed may help with their sleep. 

Room temperature can also be an essential factor. If a baby is too warm or too cold, their sleep cycle can be interrupted. Typically a baby’s room should be somewhere between 68 to 72 degrees. If the room tends to be warmer or cooler than that, you may want to consider adding a fan or a portable heater

Pay Attention to Sleep Cues

Your child will give you subtle cues as they begin to feel sleepy. Some signs to look for are: 

  • Rubbing their eyes 
  • Frequent yawning
  • Less activity
  • Staring off into space
  • Slower movements
  • Quieter
  • Slower or less intense sucking
  • Subdued
  • Lacks interest
  • Not focusing with their eyes
  • Skin around the eyes becomes red
  • Droopy eyelids
  • Not as interactive
  • Child becomes grumpy
  • Difficulty keeping them in a good mood
  • Lack of following directions

If you are following a sleep schedule, knowing how long your baby has been awake will also be helpful. If your baby stays awake for 3 hours then sleeps for 3-4, set a timer to go off before the 3-hour mark. This way, you know nap time is approaching. Timers and schedules can help you avoid hitting the overtired point with your baby, which can cause a lot of sleep problems. 

Establish a Bedtime Routine

At 4 months, babies should be getting around 10 to 12 hours of sleep each night. Babies benefit from having a nightly bedtime routine. This is a great time, if you haven’t already, to begin a routine. A sample routine can be: 

  • Eating
  • Taking a shower or bath
  • Brushing teeth
  • Getting a baby massage
  • Brushing hair
  • Reading a book 
  • Rocking to sleep

Once your routine is in place, it is best not to deviate from it. Babies like structure, and having a preset expectation of what will happen before going to bed can help your little one. 

Night Feedings are Normal at 4-months

If you are still feeding your little one at night, keep up your regular routine. Since all babies are different, yours may have 1-2 feedings still. Some babies just are not ready to give those feedings up until they are a bit older. 

Listen to your little one. They will signal when they are ready to stop feeding at night. Many will grow out of needing the extra feedings. Most often, this will coincide with the introduction of solid foods. Some babies may reduce their nighttime feeding but may not entirely give it up until they are a year. 

Try not to add in any additional feedings if you can help it. However, if your little one needs an extra feeding or two, it won’t be the worst thing in the world! Make sure you do what is best for your baby, and if you have any concerns talk to your child’s pediatrician. 


An abundance of patience is a recurring theme for parenting. It is challenging to keep your patience when your sleep is being disrupted. Give yourself and your child some leniency in this department. Offer lots of snuggles and cuddles during this time. Your little one will love it. They are bummed they aren’t sleeping too! 

Don’t be afraid to reach out to friends and family for help, either with your baby or for yourself. Try not to put too much pressure on your baby or yourself. Sleep regression will often course-correct on its own as your baby grows.  

Consider Sleep Training 

While sleep training might not be for every baby or every parent, for that matter, it can be a viable option to help everyone get more sleep. There are a few different sleep training methods to try. 

  • Cry it out, or self-soothe method
  • Ferber Method- check and console
  • Chair Method- sit with your little one as they cry it out
  • Shush-pat, picking up and putting back down
  • Bedtime routine fading- gradually spending less time in the room
  • Bedtime hour fading-gradually moving bedtime earlier

All of these methods have one thing in common, consistency. However, it can be a challenging process, and not every baby takes to the traditional methods. 

If 4-month sleep training isn’t a solution for you, you may want to consider sleep consulting. Many certified sleep specialists can help you work through whatever may be causing your baby’s sleep regression. They can also help you set a bedtime routine that may work better for your little one resulting in more sleep for everyone. 

Other Reasons For Sleep Disruptions at 4 Months

Since there is no single cause to sleep regression, other developmental milestones can trigger sleep regression. Some reasons are: 

  • Rolling over
  • Growth Spurts
  • Teething
  • Colds
  • Awareness
  • Playful
  • Temperature

All of these reasons can negatively affect your child’s sleep cycle. Many of these you have little control over as a parent. However, you can mitigate some of the effects by adjusting to your baby’s changes. 

Frequently Asked Questions About 4-Month Sleep Regression

A lot of the information out there on sleep regression can be a little confusing. Experts agree that babies need sleep, but they do not agree on the cause or best method to treat a 4-month sleep regression. Here are a few frequently asked questions and their answers to help you navigate solutions for your child’s sleep. 

Does every baby go through a 4-month sleep regression?

Not every baby goes through a 4-month sleep regression. Every little one is different and goes through the various growth and sleep stages at their own pace. If your little skips the 4-month sleep regression, they may not have any sleep disruption. 

However, it is entirely possible that their regression may come at a later age. Even 6-month-old and 8-month-old babies can experience a sleep regression. Sometimes it may even wait until they are over 12 months. 

Does swaddling help with 4-month sleep regression?

Swaddling reminds babies of being secure inside the womb. When they begin to roll over, most parents stop swaddling their babies.

Happiest Baby suggests that you continue swaddling your baby and ensure that you swaddle them safely. Also, make sure their swaddle is snug. 

If you have a snug, swaddle it can prevent your baby from rolling over and allow them to sleep better at night. Most babies can stay swaddled until they are closer to 5 months. 

Does 4 month sleep regression affect naps?

Yes. As your child’s sleep schedule changes, how they nap changes too. Between 3 and 6 months, your child should nap between 4 to 5 hours a day. They will get the remainder of their sleep at night. This allows them to reach their grand total of sleep, which should be around 14 to 15 hours. 

A sleep regression may make your child want to sleep more throughout the day. However, changing their daytime sleep pattern will affect their nighttime routine. Watch to make sure your baby does not get too much sleep during the day. Shortening naps and providing more playtime can help your baby sleep more soundly at night. 

Does sleep get better after the 4-month sleep regression? 

Sleep can get better after the 4-month sleep regression. Remember to keep up with your child’s usual routines and do not introduce any new habits that can potentially harm good sleep. 

Keep both the daytime and nighttime routines the same no matter how much your child has slept the night before. This structure can help set you up for a successful night of sleep the following night. 

Final Thoughts

Many things can upset regular sleep routines, from teething to colds. Once you make it through the 4-month sleep regression, sleep can still be hindered by other external factors. Your child can go through multiple regressions as they grow, or they can be one and done.

 Each little one is different, but setting good habits for your little guy and useful coping mechanisms for you can help you make it through each one. 

Looking for more tips for your little one? Head over to our Ages and Phases Section to see more topics.

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