Is the 4 month sleep regression real?

The 4 month sleep regression is infamous- basically every parent has heard the horror stories! And for good reason, it can really do a number on sleep for little ones. We’ve got a lot to cover in this blog, so buckle up!

Here are the topics we will cover:

• What causes 4 month sleep regression?

• Does 4 month sleep regression always happen?

• Is 4 month sleep regression permanent?

• Is 4 month sleep regression based on due date?

• Is 4 month sleep regression gradual?

• What are 4 month sleep regression symptoms?

• 4 month sleep regression and pacifier

• When is 4 month sleep regression over?

• Can 4 month sleep regression happen early?

• Can 4 month sleep regression only affect naps?

• Can 4 month sleep regression stop and start?

• How to survive 4 month sleep regression?

• How to avoid 4 month sleep regression?

• 4 month sleep regression do's and don'ts

• 4 month sleep regression solution

• 4 month sleep regression and sleep training

What causes 4 month sleep regression?

The cause of the 4 month sleep regression for babies is due to their maturing sleep cycles. As a newborn, your baby had 2 sleep cycles: light/active and deep/quiet. This is the only developmental change you see in sleep (because everywhere you look you see “sleep is developmental! They’ll figure it out on their own!”) and this is the only ACTUAL documented developmental change we see.

(When you look at other “developmental” changes, it’s pretty linear and/or follows a pretty common timeline. When kids fall outside of those spectrums, we typically call in reinforcements (think PT, OT, ST). But there’s a very WIDE range of when kids finally “figure out” sleep.

That’s why sleep itself isn’t developmental! 

There are also some other contributing factors to making sleep less than fun at this age. Usually they’re figuring out rolling which means most parents are dropping the swaddle if they haven’t already and their sleep needs change a bit, where they transition from 4 naps to 3 naps.

Does 4 month sleep regression always happen?

Unfortunately, yes. Every child will experience the 4 month sleep regression. BUT! Not every child will be affected by it, meaning not everyone will experience a disruption in sleep from it.

Some kids will breeze right on through and others… won’t. 

Is 4 month sleep regression permanent?

It is in fact a permanent change to their sleep cycles. With almost every client I get, no matter what age, I can almost always trace it back to when their child experienced this regression!

That’s why regression is a bit of a misnomer. Regression implies sleep will just go back to the way it was, that it’s a temporary change. 

But sleep physically can’t return to its previous state because of those maturing sleep cycles. Can they go back to sleeping “well” without parental intervention despite the change of sleep patterns? Maybe.

Sometimes that happens within a few weeks and sometimes it happens within a few YEARS. There’s nothing consistent in regards to this. 

Is 4 month sleep regression based on due date?

There isn’t anything concrete here as sleep cycles and maturation, we just know it can happen sometime between ages 3-5 months. 

According to the Sleep Foundation, “Baby REM sleep is one part of the sleep cycle that changes over time. However, there is no simple chart outlining sleep cycle length or REM by age. As babies grow and sleep fewer hours, they spend less of their sleep time in the REM stage.”

Is 4 month sleep regression gradual?

It *can* be something you gradually notice happening (ie more and more wakings overnight or maybe shorter and shorter naps) or it happens all of a sudden where they have horrible nights and short naps.

There’s honestly no rhyme or reason to which way it happens!

What are 4 month sleep regression symptoms?

You may notice your child waking more frequently overnight, reverse cycling, taking short naps, refusing sleep, not seeming tired at their old nap times, etc.

This is typically where I hear, “They started waking every 45 minutes (one sleep cycle) or every 2 hours.”

You may also see them practicing their skills (rolling) more and more.

4 month sleep regression and pacifier

Ahh, the pacifier. No binky-obsessed baby wants to give up the pacifier and especially not parents if they feel it makes falling asleep easier!

While a pacifier is so great for a newborn who often needs that extra support for regulating, once you hit the 4 month regression, the pacifier can become your worst enemy.

That’s because with all the new sleep cycles they’re experiencing, they’re going to typically need that pacifier to go back to sleep each and every time they wake up. The biggest predictor in overnight wakings according to research is HOW a child falls asleep at bedtime.

“..infants who were consistently put into the crib awake were more likely to be self-soothers than infants who were consistently put into the crib asleep. Infants who required parental assistance to fall asleep at the beginning of each night were more likely to require parental assistance upon awakening in the middle of the night.” (source)

Because they’ll expect those same conditions they fell asleep with to go back to sleep.

Enter the paci game, all night long.

Now, this really is a personal decision– you can keep the pacifier and continue replacing it for them until they can replace it themselves or you can ditch it all together. The highest risk for SIDS and greatest protection from the pacifier come in the first 4 months (note: not using it doesn’t put them at a greater risk). 

So there’s no reason NOT to get rid of it if you want to! Here’s a blog about pacifiers specifically.

When is 4 month sleep regression over?

Alas, it’s never really “over.” Since this is how they will permanently sleep (with 4 sleep cycles instead of 2), there’s nothing to end. 

Let’s look at some research about overnight wakings by age (and this isn’t to guilt you into changing things about sleep- it’s just to answer the question “what if I don’t sleep train/change habits, when will sleep improve?):

• According to this study, 25/60 children between ages 15-48 months had a sleep problem at the start of the study and 3 years later, 84% of those children were still experiencing a sleep struggle

• This study found that children who had a sleep problem at 8 months of age, 41% still had difficulty 3 years later

• Even younger– in this sample of 1741 Canadian children, the study found that those who were sleeping 6 hours straight at 5 months generally continued to do so; but for those that weren’t at 5 months or 17 months, 32.9% were still not getting a 6 hour block of sleep at 29 months of age

• In a study of persistent sleep problems, researchers found that children who had sleep problems as infants, 21% still had difficulty at 3 years old.

Does that mean you’re just doomed to not have a good sleeper? Absolutely not!

You’re definitely not alone in experiencing sleep difficulties. You’re in good company, that’s for sure 🥴

It’s honestly a matter of behavioral modifications, aka changing habits around sleep. And you should only do that when you want to!

Here’s another blog about night wakings!

Can 4 month sleep regression happen early?

It certainly can– as we know there’s no linear timeline that every single baby follows, we just know it happens after their circadian rhythm develops and research shows that an infant’s circadian rhythm is fully developed by 12 weeks.

After that, it’s fair game.

Can 4 month sleep regression only affect naps?

It could– I rarely see it only affect naps, but it can AND it can last longer even with sleep training. 

This is because it takes longer for day time sleep to organize in the brain (thanks to the lower drive to sleep during the day) and day time sleep may not consolidate until 5-6 months despite the regression happening between 3-5 months.

Can 4 month sleep regression stop and start?

Maybe! Sometimes parents wonder this because there will be a few good nights sprinkled in with the not so good ones. 

My anecdotal working theory for this is that they build up a sleep debt by waking frequently/taking short naps and sort of have a “catch up” night here and there.

How to survive 4 month sleep regression?

What a loaded question!

I don’t think anyone should just resign themself to surviving through something, playing the waiting game to get to the other side UNLESS that is what is working for you and your mental heatlh!

I always say “choose your hard” and sometimes choosing to do something different is HARDER than staying in the situation you’re in. In that case, try these things:

• Go to bed early (yep, clock in more overnight sleep, even if it’s broken up)

• If you choose to bedshare, please be as safe as you possibly can (remember there’s no way to eliminate all risks)

• Take shifts with a partner (getting a solid chunk of sleep can be extremely helpful)

• Nap during the day if you can (don’t underestimate the power of a 30 min cat nap)

• Ask for help/go light on other duties around the house

If you do want to sleep train, now is a totally fine time to do so!

How to avoid 4 month sleep regression?

You can’t make it go away or not happen at all, but you can minimize the effects/damage of it! 

By this age, my second and third child were falling asleep independently at bedtime and didn’t have any dependent sleep props in play. 

That meant that when their sleep cycles matured, they already had the skill of falling asleep without help, which meant they could go BACK to sleep during the night when they woke if something wasn’t preventing them from doing so.

Which meant for us, the regression was a small blip and not something that totally rocked our world. The night Hannah turned 4 months was the very first night she slept completely through the night without feeding.

But a week later, she learned to roll and we had some disrupted sleep for a few days. That was the most “regression-y” behavior we had. 

(We never noticed a regression with Noah because his sleep was already awful, didn’t get worse at 4 months 😅)

Lukah took 45 minute naps until he was 6-7 months old and started finally taking longer ones when we transitioned to 2 naps. You can read that story here!

4 month sleep regression do's and don'ts

These are just more tips if you want them!

4 month sleep regression do’s:

• Do work on positive sleep associations and routines

• Do ensure they’re not in the swaddle any longer

• Do feel good about extending their short naps if you want

• Also, feel good about an early bedtime for everyone

• Ask for help

• Take shifts

• Let some chores go

• Do practice more rolling

4 month sleep regression don’ts

• Assume the worst and that sleep will never get better

• Don’t wait until you hit rock bottom to get help

• Don’t be afraid to sleep train

• Don’t think every waking is for hunger

4 month sleep regression solution

As a pro-sleep training consultant (though not a pro- every baby needs to be sleep trained consultant, there’s a difference), I truly believe it’s a valid option for those who aren’t willing to wait it out or those who are tired of waiting it out. 

As research shows us, there’s no specific time that sleep will improve without parental intervention and it is absolutely OKAY to intervene in this instance. Remember that sleep is like 50/50 nature/nurture which means we do have influence over their sleep– that’s a good thing!

Sleep training doesn’t mean never responding to your child or even using separation based methods, night weaning, etc. It can be done in a way that you feel good and confident about.

4 month sleep regression and sleep training

It really is the perfect time to make changes around sleep. If sleep is going great– then don't’ fix what isn’t broken!

But you don’t have to wait for things to get better or get through the regression! Sleep training is often the exact way to get to the other side and start getting some solid sleep again. 

So to answer the question, “is the 4 month sleep regression real?”…. yes, it is a very real, science backed thing that happens for babies. It doesn’t mean you’re doomed and sleep will be awful until who knows when. It does mean that you may have to make changes around sleep in order to improve it though and there is NO shame in doing that if you choose to! My 1:1 services are for that exact purpose, so check them out and don’t delay getting good sleep any longer!