Four Month Sleep Regression: How Long Will This Last?

Infant Sleep

You’ve finally found your rhythm, you’re both finally getting some sleep, your baby has been going to bed like a dream come true…and then it all comes to a grinding halt. When you’re a new parent, exhausted from a baby who’s not sleeping well, the last thing that you want to hear about is sleep regression.

But at right around four months, it’s a reality nearly every parent is going to face. So here’s what you need to know to survive conquer the four month sleep regression.

What is the 4 month sleep regression?

Newborns only have two stages of sleep: slow wave and REM…until they hit four months old. Slow wave is that non-REM stage of sleep that lasts between 20-40 minutes. At about 4 months, they will start to spread their sleep time over four stages of sleep, not just two, and those new stages? Well, they are much easier to wake up from.

While you will realize it’s still the middle of the night when you wake up and drift back off to sleep, your sweet little baby doesn’t know that yet. She hasn’t learned to go back to sleep (at least not right away and without your help) and so it seems like your sweet sleeping angel is now the thing of distant dreams.

This really isn’t a regression, though. She’s not reverting to old habits or losing ground she’s gained. She’s simply progressing to the next stage of mental and physical development. In fact, this isn’t a regression at all; your little one is making progress!

A Sleep ‘Progression’

There are times, however, that sleep disturbances are regressions, and we recommend handling them a little bit differently then the 4 month sleep “progression”. For example, teething. That’s a temporary (albeit repeated) condition that will disrupt your baby enough for you to notice regressive patterns at bedtime.

Travel, illness, and other major changes in circumstance are expected to disrupt sleep time. But at four months? It’s just your little one growing up and making progress.

Sleep Training During the 4 Month Sleep Regression

You’re not alone in this frustration of sudden sleeplessness and there is hope. I promise, your baby will sleep well once again — and truly, even better than you can imagine.

Here are some tips we tell every family of a 4 month old to help reclaim their sleep…

1. No Lights In The Room

That’s right, keep things dark. A dark environment is a signal our brains are hardwired to recognize as a sign that it’s time to sleep.

Your 4 month old baby isn’t scared of the dark; she’s simply waking up in a new place, from a new way (remember, her body didn’t do all this just a couple of weeks ago!), and her fight and flight response kicked in. You’ll comfort her, she’ll learn it’s okay, and she’ll go back to sleep. But! Falling asleep is much harder if there’s light signaling that it’s time to wake up. We like to make sleep as easy as possible for our babies.

2. White Noise In The Room

While this could be considered a sleep prop by some, we view it as more of a tool.

For our purposes, a prop is more of an external item that needs interaction. This is a noise in the background be it from a white noise machine, a fan, or other device that will help reduce baby’s awareness of sounds like the doorbell ringing, the dog barking, or a telemarketer calling.

This will help your little one move through those two light stages of sleep (where she can be easily awoken) and make her way to restorative and REM phases.

3. Have A Good Routine

Routines are good for children of all ages, not just your four month old. At 4 months a routine can help your little one prepare for bed without relying on the breast or bottle. Your regular 20-30 minute predictable rhythm of behavior will start to signal to your child that it’s bedtime and help her get ready to sleep.

If baby’s getting fussy, you know it’s already been too long between sleep times and you’ll need to be more mindful of the clock. At 4 months, a typical schedule will include about 2 hours of time awake between naps. Bedtime will be around 7 or 8 at night.

How long does the 4 Month sleep regression last?

The good news is that once you get past the four month milestone, you’re past it. That’s it. No circling back to it. The other piece of good news is that babies that have been gone through our Newborn Plan don’t experience sleep disruption during this transition.

How long this sleep regression lasts is dependent on many things. Things like how your child falls asleep, their sleep schedule, if there’s other factors impacting sleep, or even their personality. Your baby may make this transition quickly and seamlessly…or you may end up exhausted and near tears, feeling hopeless. If you are lost, you don’t have to do it alone. Our free call is always available to you.


By Katie Pitts, Founder & CEO of Sleep Wise Consulting

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