The 4-Month Sleep Regression: What’s Really Going On (And What To Do About It)

Written by Andria Gordon

This is a segment of Raising the North where we feature real stories from parents, plus expert insights from the individuals and businesses supporting families across the country.

We consulted the sleep expert team over at Have Baby. Must Sleep. on how to navigate that pesky 4-month sleep regression. Read below for tips on how to best prepare you and your family for your baby’s developmental milestone.

What is the 4-month sleep regression?

The 4-month sleep regression is one of the most talked-about baby sleep challenges and often puts new parents on edge in the weeks leading up to the 4-month mark.

Let’s talk about what this really is and why you don’t need to worry too much.

The 4-month sleep regression is a permanent change in how your baby sleeps. They don’t forget how to sleep; instead, their sleep cycles mature from newborn patterns into adult-like stages. Instead of drifting seamlessly between cycles, they now fully wake between each one. This can be more noticeable for babies who are used to being supported to fall asleep or return to sleep.

This developmental leap means your baby may start waking more often at night, taking shorter naps, or needing more help to fall asleep. However, not all babies struggle with the transition. It’s not a step backward; it’s a normal and lasting shift in how your baby sleeps.

Why the 4-month regression feels so hard

The 4-month baby sleep regression often hits just when things were starting to feel predictable. Your first stretch of night sleep was lengthening, and you may have even started to see a few longer naps emerging.

The regression can look different for every baby. Some transition with very little disruption, while others suddenly start fighting naps or bedtime, waking after 30 minutes, or taking much longer to settle back to sleep. Some may even need to be held again for every nap or at bedtime.

On top of that, you’re probably exhausted, emotional, and trying to manage daily life. It’s easy to feel like something’s wrong, but nothing is broken. Your baby’s brain is simply growing and reorganizing.

The science behind this sleep change

At around 4 months, your baby develops distinct stages of sleep: light, deep, and REM. They now cycle through these stages every 45 to 60 minutes, just like adults do. The difference is that adults know how to drift back to sleep independently, while babies often call out for the same help they had when falling asleep in the first place.

This is why you might start hearing more about sleep associations and how gradually fading them out can help improve sleep during this stage and beyond. Rocking, feeding, using a pacifier, or holding are all effective and nurturing ways to help young babies fall asleep. However, when these become the only ways your baby can fall asleep, they can lead to more frequent night wakings once the regression begins.

Expert tips: How to survive the 4-month sleep regression

Here’s what the team at Have Baby. Must Sleep. recommends to help your baby sleep better during this stage.

1. Follow Age-Appropriate Wake Windows

At 4 months, most babies can handle 90–120 minutes of awake time between naps. If your baby shows sleepy cues, you can go with those (zoning out, turning away from toys/you, rubbing their face) however wake windows are a great way to ensure your baby doesn’t get overtired between their next sleep. Missing the window can lead to overtiredness and more night wakings.

2. Set a Consistent Bedtime Routine

A calm 30-40-minute routine signals sleep: bath, feed, diaper, pajamas, quiet song or books, crib. Keeping the order consistent helps your baby know what’s next.

3. Optimize the Sleep Environment

A dark, cool, and quiet space sets the stage for better rest. Brown noise (or white noise) can help block household sounds and cue your baby that it’s time to sleep. Keep the volume around 40 to 50 decibels and place the sound machine at least 7 feet away from your baby’s sleep surface.

Always follow safe sleep guidelines: your baby should sleep on a flat, firm surface with nothing else in the crib. At this age, a sleep sack or transitional swaddle is best to keep them cozy while still allowing safe movement as they begin rolling.

4. Practice Calm-But-Awake

Helping your baby learn to fall asleep in their crib (not fully asleep in your arms) encourages them to connect sleep cycles independently. Putting them in calm but awake and helping them if needed once in the crib will help them learn to fall asleep on their own which means there is a better likelihood of them returning to sleep independently. Actual sleep work isn’t recommended until your baby is at least 16 weeks old.

5. Stay Flexible

Some days go perfectly, others don’t. Baby sleep progress is rarely linear so give yourself and your baby grace through this phase.

Realistic tips for getting through it

• Ask for help early. Whether it’s your partner, family, or a consultant, support makes a world of difference and can help you navigate things when you are feeling too tired or overwhelmed.

• Keep a short log. Track naps and feeds for a few days to see patterns.

• Don’t compare. Every baby’s rhythm is unique. Trust us on this one.

• Protect your mental health. If you’re feeling overwhelmed, our More Than Sleep team (sleep consultants + registered social workers) can support you emotionally as well as practically when you are looking to start sleep work.

Key takeaway

The 4-month sleep regression isn’t a setback, it’s a milestone. Your baby’s sleep is maturing, and with gentle routines and the right support, restful nights are closer than you think. You’ve got this.