baby in crib with sister watching


A sleep regression is a period of time when a  baby or toddler who had previously been sleeping well begins to have difficulties with their sleep such as frequent night wakings, short or skipped naps and early wake ups.

Why is it happening? 

This is a sign that your baby's sleep cycles are maturing.  Although there are regressions at other ages (something I will be diving deeper into over the next few months so stay tuned!), the permanent change to their sleep cycle during this time is the one they will be on for the rest of their lives!  Newborns only have 2 sleep cycles but once this regression occurs they will have 4 sleep cycles, just like adults.  This means your baby will be spending more time in a lighter, non-REM stage of sleep which can contribute to more frequent wake ups.   It also has to do with developmental milestones that are occurring such as recognizing faces, rolling over, growth spurts, being more aware of the world around them and becoming more sensitive to their environment.

How long does it last?  

Sleep regressions typically last 2-6 weeks. If it lasts longer than that then it is time to evaluate if your little one has developed some new sleep crutches during this time.  

When does it occur? 

The 4 month sleep regression can start as early as 3.5 months or as late as 5 months. 

When does it end? 

Technically it doesn't end since your little one will have experienced a permanent change to their sleep cycles however the sleep disruptions should be done by 2-6 weeks.  If you are past that point you'll really need to consider what new habits may have developed as a result of the regression.

Does every baby go through the 4 month sleep regression? 

While it is very common and most babies do, some will sail right past it and it won't seem to affect them.  There are more regressions in the future though - they typically occur at 8 months, 10 months, 12 months, 18 months and 2 years.  

How much sleep should my 4 month old be getting?  

You will want to aim for approximately 12-15 hours of sleep within a 24 hour period. 

Can I put my 4 month old on a schedule? 

At 4 months old most babies haven't developed predictable sleep patterns yet.  You should follow wake windows at this age and expect that their sleep may not be consistent or predictable until 6 months.  This doesn't mean that you can't follow some form of a schedule however!  I have included more information below that discusses the importance of using an eat/play/sleep schedule and how to incorporate routines into your day.

What can I do about it?  

Here are some of my top tips for managing this regression!
    1. If you haven't already, try to work on establishing an eat - play - sleep routine.  This allows for some separation between feeding and sleep so that your baby won't begin to associate the two.  It will also ensure he or she doesn't become too drowsy before naps or bedtime which can also lead to more frequent wakings.  Your routine doesn't need to be too complicated, just something simple such as feeding the baby when he or she wakes, then doing a diaper change and some floor time to allow them to work on new skills and to ensure they are physically tired before sleep.

    1. Create the perfect environment.  This regression makes babies more aware of and sensitive to their surroundings which means light coming in through the window or loud noises in the house may wake them, even if they didn't before.  The perfect sleep environment is between 68 and 72 degrees, white noise and a pitch black room.  Babies can detect the slightest bit of light even with their eyes closed so at this stage it becomes important to block all natural and artificial light.  Check if your baby monitor, wipes warmer, humidifier or sound machine have a glowing light and if so, you'll want to block those as well.

    1. If your baby is still in a swaddle continue to use it until they have reached the point they are no longer able to continue to do so based on the manufacturer's instructions and the American Academy of Pediatrics recommendations.  If your baby has outgrown their swaddle you can switch to swaddle sleeves as a gently weighted and comforting alternative during this transition time.  The Swaddle Sleeves help dampen the startle reflex and are great for helping your little one transition from the confines of a swaddle to a more open environment all while helping them to feel secure. I like to see parents using a sleep sack (the Swaddle Sleeves Sack is a great option!) as well as it can act as a positive sleep association to help cue your baby that it's time for sleep.

    1. Start using a pre-nap and a bedtime routine, if you are not already doing so.  These routines help send a signal to your baby that it is time to prepare for sleep.  It allows their bodies to begin the process of winding down as they prepare for sleep.  When this happens their breathing slows and they may utilize some self soothing techniques such as thumb or pacifier sucking. Your pre-nap routine doesn't need to be elaborate, it can be a simple and condensed version of your night time routine.  You can read a book or two, sing a few lullabies, put baby in their sleep gear (swaddle, swaddle sleeves, sleep sack, etc), turn on the white noise machine and then lay them down for sleep.  The nighttime routine is typically longer, about 30-45 minutes.  You should feed your baby at the start of your routine to ensure he or she isn't becoming too drowsy prior to sleep.  It's also great to incorporate a bath and a quick massage if you have time to fit it in.  Make sure you start your routine 45 minutes before your baby's scheduled bed time so they aren't going to bed overtired.

    1. Follow proper wake windows.  Wake windows is a term for the amount of time your baby should be awake before they sleep again.  Wake windows change as babies get older and the best way to ensure a solid nap and good night time sleep is to lay them down at the correct time, before they become overtired.  When babies become overtired their bloodstream is flooded with stress hormones.  These hormones, cortisol and adrenaline, make it difficult for your baby to settle to sleep or stay asleep for a long enough period of time.  I am including a copy of my wake window chart so you have an idea of the timeframes to stay within.  Keep in mind, wake windows are a guide and each baby is different and will have varying needs.  The general rule of thumb is that your baby will be able to tolerate a smaller wake window earlier in the day and as the day progresses, they should be able to tolerate a longer window of time.  A great way to determine if your wake windows are working is to keep a sleep log.  Keep track of everything to see what works and what doesn't.  When making adjustments to your little one's wake windows, give it a period of 3 days before making any additional changes.

    1. Lay your baby down at the proper time.  You'll want to lay your baby down 10-15 minutes before their scheduled nap time. This will allow them to fall asleep before reaching the point of becoming overtired. It is normal for babies to take up to 15 minutes to settle themselves to sleep so you want to give them ample space and opportunity to do so.

    1. Give your baby plenty of floor time during this regression. This is a common age for your little one to learn how to roll over and by offering lots of tummy time you can hopefully avoid them working on this skill when they should be sleeping! Even if your baby already knows how to roll, the extra floor time is great for their continuing development.

    1. Ensure your baby is receiving full feedings. You want to feel confident that they aren't waking due to hunger. Feeding your baby every 2-3 hours during the day equates to an extra feeding vs. if you were to feed them every 4 hours.

    1. Lay your baby down awake. Try your best to give them the opportunity to fall asleep on their own.  If they aren't able to achieve it, that's okay!  You can grab them and help them to fall asleep. You want to practice this skill 1-2 times a day in those first three months of life when possible. If you are past that point then that's okay - you can start now!

    1. Stick to your routine. Babies thrive on consistency - it helps them to feel secure!

    1. Adjust baby's bedtime.  If your little one has a day of short or missed naps, don't be afraid to bring bedtime up!  You can do as early as 5:30pm if needed to help them get some of that critical restorative sleep!

    1. Don't be afraid to ask for help.  This regression can be exhausting, especially if your little one is waking frequently in the night.  You can ask your partner, friends or family for some help with the baby so you can take a nap or get some much needed self care time during the day.

    1. Give yourself (and your baby!) some grace.  This regression can be especially taxing on parents.  It's really okay to rock or feed your baby to sleep if they're having a difficult time.  You can also try giving them a nap in a baby carrier, on a walk in the stroller or during a car ride.  Giving your little one plenty of extra bonding and cuddles will help make them feel secure.  You do want to continue to practice teaching them the skill of falling asleep independently but don't panic if you aren't seeing success right away.  It takes time.  

    1. Consider sleep training.  There's lots of methods out there - do some research and decide which one is right for your baby and your family.  Have a clear understanding of how to tackle night wakings while still providing age appropriate feedings.  You want to approach this with confidence as it will help reassure your baby if you are being clear and concise in your actions.

  1. Seek help from a professional. If you have exhausted your options and need help, certified sleep consultants are here to help!

In conclusion, the 4-month sleep regression points to both a trying but exciting time.  Although it may lead to some sleep difficulties, it also means your baby is experiencing growth and development which is a wonderful thing!  The main things to work on during this time:

  • Ensuring the routine, feedings and environment are correct 
  • Laying baby down at the proper time and following wake windows
  • Being consistent while also giving yourself some grace 

Do you have a baby who is experiencing a 4-month sleep regression?  What have you found has helped you most during this time?  Leave a reply in the comments below!  


Rachel Christopher is a certified pediatric sleep consultant, owner of The Slumber Studio, and mom of three. She is passionate about helping families get the rest they need. After experiencing sleep deprivation and difficulties with her middle child she knew she never wanted any mom to feel the way she did.  It became her mission in life to guide, educate and empower families with the tools necessary to achieve great sleep. Rachel specializes in custom sleep plans for ages 4 months to 4 years that cater to your child’s temperament and your personal parenting philosophy. 


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