The 4 Month Sleep Regression

What is the 4 month sleep regression?

The 4 month sleep regression is probably one of the hottest topics on mommy boards. Moms trying to figure out how to avoid it, how long it will last and what they can do about it.   So many of my clients come to me saying that their baby was a great sleeper until about 4 months and then suddenly they were up every hour of the night!

The good news is that this is less of a regression and more of a maturation of your baby’s neurological development! Let’s look at how a baby’s sleep develops these first few months of their life.

The Newborn Months:

These first few months of your baby’s life his sleep will be pretty unorganized. You may experience day and night confusion, which is when a baby sleeps a lot during the day and not much at night. If this is the case try exposing your baby to a lot of light during the day, have him nap in a well-lit room. At night make sure the room he is sleeping in is nice and dark. Usually, if you do this you will find that by 8 weeks the confusion should be gone.

These first few months a baby does not rely on sleep cues or behaviors to fall asleep. Some babies may simply fall asleep when they are tired and some may need more help by rocking, nursing or bottle feeding. Newborn babies also don’t have distinct sleep cycles. Instead of cycling between deep and light sleep like we do, newborns sleep deeply most of the time. Don’t worry about spoiling your baby at this point, once your baby is asleep, even if you rocked him to sleep, he should stay in a deep sleep the entire nap

Things to focus on in months 0-3:
  • Keep your baby well rested – Most babies need to sleep every 45 minutes – 1 hour.
  • Do whatever you need to get him to sleep. Don’t worry about spoiling him!
  • Don’t worry about a schedule yet – Your baby’s biological sleep rhythms aren’t mature enough yet to fall into a predictable pattern.
  • Focus on bonding with your baby and recovering from his birth.

Months 3-4

Cognitive Development:

Your baby is going through some major cognitive developments. He is becoming a social being, laughing, babbling and smiling at you. Most likely he thrives on your attention, doing whatever he can to make you smile or laugh. At this point, you can help protect his sleep by making sure his sleep environment is spot on. I like to think of it as a cave, cool dark and quiet. He would rather be spending time with you than sleeping, so make sure to set him up for success.

Sleep Development:

Around 4 months your baby is going through a massive development in his sleep cycles. His sleep is starting to function more like an adult’s. First of all his sleep is starting to become more organized. You might notice more pronounced times of wakefulness and sleepiness during the day. He is also starting to move between sleep cycles of deep sleep and light sleep. What that means for you is that when he reaches a cycle of light sleep he may start to wake.  If the cues that were present when he fell asleep aren’t there anymore, such as rocking or nursing, he probably will not be able to fall back into a deep sleep.

This leads to the dreaded catnap, the 30-40 minute nap that leaves your baby cranky and tired and you without a break. It also causes babies to start waking every hour or two during the night and call for your help to fall back asleep. Don’t worry this is a normal phase and you should be excited that your baby is growing and maturing! (Yeah right, after a few weeks of no sleep who can be excited about anything?)

Growth Development:

Babies feeding needs are constantly changing, and many people think the 4 month sleep regression is caused by a growth spurt. Yes, your baby will most likely go through a spurt around this time. For a short period you may need to feed more during the day and night. I always encourage mothers to feed on demand in order to meet their babies changing feeding needs and encourage their milk supply.

However, be careful that these increased feedings do not continue past the growth spurt. Most growth spurts only last 1 -2 weeks. If you find yourself still feeding every two hours for longer than that your baby has probably developed a habit of waking.

What Can I Do?

Now that you know why your baby is only napping in 40 minute chunks and waking every 2 hours, you are probably wondering what to do about it. Or are you doomed to be a zombie for the rest of your little one’s childhood?

Don’t worry, there is a lot you can do to help your baby sleep better. Many people ask if they should wait until after the regression. Remember, this isn’t a regression that will end. It is a change in your baby’s sleep cycles and cognitive development. So no, I don’t recommend waiting. If you do, you may find yourself months down the road still sleep deprived.

Sleep Environment:

Because your baby would rather be up playing with you, it is important that you set him up for success by creating a sleep cave that will naturally promote sleep.

  • Cool: I recommend a temperature between 68 -72 degrees for your baby’s room. Your body naturally cools as you sleep. Overheating will make it more difficult for your baby to fall asleep and stay asleep. Overheating also increases the risk of SIDS.
  • Dark: Darkness stimulates the body to produce melatonin the sleepy hormone. Darkness will also help your now social baby to focus on sleeping rather than all the fun stuff going on in the world!
  • Quiet: Our brains are constantly registering the sounds they hear around them. It is much easier to fall into a deep sleep if your brain is not trying to filter outside noises. I always recommend a white noise machine to help drown out household noises. It can also serve as a cue to sleep if you incorporate it into your bedtime routine.

It is important that your baby is taking some of his naps in his crib. At this point he is going to have a much harder time sleeping on the go. Not only will his naps be shorter, but they will also be less restorative. If your baby ends up overtired from poor naps during the day he is going to have a harder time falling asleep and staying asleep at night.

Age Appropriate Schedule:

Most babies around 4 months old need to sleep every 1.5 – 2 hours throughout the day. If you keep your baby up for much longer than this it is going to be difficult for him to fall asleep. I recommend keeping one eye on your baby and one eye on the clock. If you start to notice your baby acting tired it is probably time to put him to sleep. If you find yourself approaching the 2 hour mark and haven’t seen sleepy cues yet I would still try and put him down for a nap. Around this time sleepy cues become less reliable and you may need the clock to help guide your naps. If you need more help deciding on an age-appropriate schedule click here for my article about schedules.

Encourage Self Soothing:

Many people worry that this is going to mean hours and hours of crying. But if you start now you should be able to help your baby learn to fall asleep independently with little protest. At 4 months or younger, you can start by putting him in his crib drowsy but awake. If he protests, soothe him a little but try and give him the space to fall asleep independently.  Often babies are ready to fall asleep independently, we just don’t give them the chance to try. As Magda Gerber writes in Dear Parent: Caring for Infants With Respect, “Infancy is a time of great dependence. However, babies should be allowed to do some things for themselves from the very beginning.”


The 4 month sleep regression can be tough but remember, with the development of good sleep hygiene you can help your baby become an amazing sleeper. My twins were great sleepers up until about 4 months and then it all fell apart. I thought I might never sleep again, but with some research and some help from a sleep consultant, they became the best sleepers I know. We have had some bumps in the road but by being aware and setting them up for success they continually amaze me with their sleep.

If you implement these tips and still are struggling, sometimes you just need a little help from an expert. As a sleep consultant, I help people just like you. We can work together to create a plan suited to your personal views, goals, and beliefs. Often the most important aspect of my services is the support I give as you implement your plan. I will be there every step of the way as you work to improve your baby’s sleep. I will answer your questions, provide advice and discuss when we may need to adjust your plan. Right now you may feel like there is no hope for your family’s sleep, but with help, you can all dream again!





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