Understanding the Four-Month Sleep Regression: What’s Really Going On?
If you're approaching the four-month mark, in the thick of it, or still feeling like you never really got out of it, you're not alone. The four-month sleep regression is one of the most talked-about stages in a baby’s sleep journey. But what actually causes it? And more importantly, how can we manage it without it derailing your little one’s sleep altogether?
What Causes the Four-Month Sleep Regression?
The four-month sleep regression is not really a regression at all—it’s a developmental progression. Around this age, your baby’s sleep cycles begin to mature. They shift from newborn-style sleep (where there is less defined sleep cycles) into more defined, adult-like sleep cycles. This means they now move through light and deep phases of sleep, and naturally wake between cycles. This awakening though is primarily to check everything is as it was when they fell asleep, we all do this as adults but are unaware of these transitions. So why does it become an issue with more night waking and the dreaded 4 month period.
At this same time, babies become more aware of their surroundings, and their need for familiarity & certainty increases. These changes are completely normal and expected, but they can make sleep more fragmented—especially if your baby relies on external aids like rocking, feeding, or dummies to fall asleep or return to sleep. So think of it like this, if your little one uses external measures to put themselves to sleep, then they awaken and something is changed, missing or different, plus they aren’t sure how to drift back off to sleep. This is why we then get the call outs and how the pattern of dependency begins.
Is This Really a Regression?
Here's the key: coming to a certain point of awareness between sleep cycles is normal. The challenge arises when babies have learned to depend on a specific sleep association to drift off, and then that something is “missing” when they wake mid-cycle. If your baby is rocked to sleep, for example, and wakes up in their cot without being rocked, they may fully wake and cry out for that familiar experience.
This isn’t because they can’t sleep, it’s because they’ve learned to associate sleep with something external or they just need more guidance to better sleep habits. Babies are born with the ability to sleep. But when we consistently step in and play the role of sleep for them, they can begin to believe they need us every time they wake.
Why Does It Seem So Specific?
You might notice that your baby isn’t just looking for comfort, they’re looking for the exact thing they’ve become used to. If it were just a general need for comfort or connection, why won't they settle with a different comfort measure, like Dad instead of Mum, or rocking instead of feeding, car instead of carrier etc?
This specificity tells us something important: it’s not just developmental, it’s learned. The fact that many babies sleep well also shows us that it’s not simply a developmental milestone and the fact that there is no evidence to support a specific age or month for better sleep as a milestone is also a big hint. If your baby won’t settle unless you feed them for the sixth time that night, or won’t go back to sleep without the dummy they were given at bedtime, it’s not simply a regression that means you have to stay stuck, they’re repeating a pattern that’s been reinforced over time. You can change this and support your babe to beautiful, good quality sleep.
How to Minimize the Four-Month Sleep Regression and embrace the Progression (And Get Back on Track)
The good news? You don’t have to wait it out or dread it. This is a perfect window to support new skills and healthy sleep habits. Here's how:
1. Nail the Right Awake Times
Around four months, awake windows typically range from 1 hour 30 minutes to 1 hour 45 minutes using the Bambii app will take the guess work out of your little ones schedule, extending slightly as the day progresses. Earlier in the day, your little one might need less awake time. Aiming for around four naps per day is common at this stage, if they’re still on five, that’s okay for now.
2. Protect Sleep Pressure
Use their awake times well and be mindful of them resting and re booting. If they are drowsy or sleepy on feeds. Having long, relaxed feeds near nap time. Dozing in the car or pram. Rocking or cuddling that slips into light sleep, then wakes on transfer, these things are ok unless they start to impact settles and sleep length.
You want your baby going down wide awake. Keep awake time engaging, playful, and connected.
3. Build Self-Settling Skills
If your baby is always helped to sleep, many will struggle to then know how to link sleep cycles independently. This stage is a great time to gently teach settling skills, helping your baby feel confident in falling asleep (and back to sleep) in their own sleep space.
4. Shift to Feed–Play–Sleep
Once feeding is well established, consider moving toward a feed–play–sleep structure. This prevents feeds from becoming the last thing before sleep, which often leads to feeding-to-sleep associations.
5. Mind the Resettles
Night wakings at this stage should be met with calm support and comfort but try not to always totally put them back to sleep. Ask yourself: Am I playing the role of sleep again? Support your baby without repeating the same pattern that may be keeping them stuck. Changing sleep habits though is an overall change in patterns and I recommend a program to teach you how and one that also supports you to set them up well and have guidance along the way Shop All – The Gentle Sleep Specialist . Changing sleep habits shouldn’t be just a method, it should be a holistic change.
Final Thoughts: It’s a Progression, Not a Setback
This stage doesn’t have to derail sleep. With the right tools and understanding, your baby can transition through the four-month sleep regression smoothly and even come out the other side with stronger sleep habits than ever.
If you’re navigating this and feeling unsure, know that you’re not failing—you’re learning alongside your baby. And sometimes, gentle guidance is the greatest gift you can give them (and yourself).
This is not medical or feeding advice, always follow Sleep Safe guidelines.
The Gentle Sleep Specialist
