Understanding Baby Sleep Regressions: Why They Happen, When to Expect Them, and What to Do About It

There’s nothing more stressful than when your baby is finally sleeping well and then suddenly, they’re not. If your once-great sleeper is now waking frequently, fighting naps, or suddenly wide awake at 4 a.m., you’re likely dealing with a sleep regression.

If you’re like me, the panic hits fast: What changed? What do I need to fix?

Unfortunately, baby sleep regressions are completely normal. Sleep can be up and down for the first few years of life, and once you understand when regressions happen and how to handle them, they feel much more manageable.

Most baby sleep consultants agree that regressions are often linked to big developmental milestones (like learning to roll, crawl, stand, or talk). As your baby’s brain and body practice new skills, their sleep can take a temporary dip. Think of it like Christmas Eve: they’re so excited, they can’t stop practicing, even at 2 a.m.

Signs of a Baby Sleep Regression

Wondering if your baby’s going through a regression? Here are common signs:

• More frequent night wakings

• Shorter naps

• Trouble settling at naps or bedtime

• Early morning wakings

• Needing more assistance to fall asleep

If that list sounds a lot like the signs your baby’s sleep schedule needs an update, you’re right, they do overlap. Let’s look at when baby sleep regressions typically happen, and how to tell the difference between a short-term regression and a schedule issue.

When Sleep Regressions Happen

Sleep regressions happen on and off during the first two to three years of your baby’s life. Every child is different, so your baby may experience some (but not all) of these. Here are the most common ages when sleep tends to take a dip:

• 6–8 weeks: Your baby is becoming more alert and soaking in the world. Too much stimulation can make it harder to settle.

• 3–4 months: The famous 4-month sleep regression. Your baby’s sleep cycles mature, which can mean more night wakings and short naps, but also deeper, more restorative sleep once they adjust. This sleep structure shift is permanent, but the worst of the regression symptoms last 2~ weeks.

• 8 months: Separation anxiety and object permanence develop. Your baby realizes you exist even when you’re not nearby, making it harder to fall asleep alone.

• 10 months: It might look like your baby is ready to drop a nap, but this is almost always a false alarm.

• 12/15 months: Learning to walk, talk, and explore the world is exciting, but all that activity can lead to restless nights.

• 18/24 months: Toddlers begin testing boundaries and experiencing FOMO (fear of missing out), which often shows up as bedtime battles. There is also sometimes another period of separation anxiety around this age.

• 30 months (2.5 years): Often the last “regression” before most kids truly drop their nap around age 3 (though there’s a wide range of normal).

The 4-Month Sleep Regression Explained

Unlike other sleep regressions, the 4-month regression is a permanent change in how your baby sleeps. Around 3–5 months, their sleep structure starts to look more like ours.

Here is why this is tricky: none of us actually sleep straight through the night. Even adults wake up several times between sleep cycles, we just know how to roll over, get comfy, and fall right back asleep without thinking (or being aware) about it.

For babies, though, this is brand new. The sleep cycles are now longer and deeper, which makes it harder for them to move from one to the next without fully waking. If they’ve been used to falling asleep with help (like rocking, feeding, or bouncing), they often need that same help each time they come to the surface between cycles, which can be every 30–60 minutes.

That’s why this stage can feel like your once “good sleeper” suddenly forgot how to sleep. They didn’t forget, their sleep structure changed, and they’re learning how to manage it.

This is also why independent sleep skills start to make such a difference around this age. Babies who learn to fall asleep on their own at the beginning of the night often find it easier to link sleep cycles overnight because nothing changes between when they fell asleep and when they wake between cycles.

How to Tell If It’s a Regression or a Schedule Issue

👉 If sleep was going well and suddenly got worse (without illness or travel) and it’s been less than two weeks, it’s probably a sleep regression. Stay consistent and give it time.

👉 If sleep has been hard for more than two weeks, it is time to dig deeper and start making a few changes. The most common thing that needs to be adjusted if sleep was previously going well, is your baby’s schedule!

What to Do During a Sleep Regression

I recommend waiting about two weeks before making any big changes. Most regressions pass on their own in that time. Making schedule changes too soon (like dropping a nap or pushing bedtime back) can actually make things worse, leading to overtiredness and even more wakings.

Here are straight-forward sleep tips that help during every regression:

✔ Stick to your normal routine. Try not to introduce new habits you don’t want to keep long-term (like rocking to sleep every time).
✔ Keep the schedule similar. If your baby skips or shortens a nap, you can move the next nap or bedtime earlier by 15–30 minutes, but avoid major shifts.
✔ Let your baby rest quietly. If they’re happy in the crib but not sleeping, that downtime still helps their brain rest and keeps your routine on track.
✔ Keep wake time consistent. If your baby has a rough night, let them sleep in a little, but aim to keep wake time within 30 minutes of normal to protect their circadian rhythm.
✔ If things haven’t improved after two weeks, it’s time to make small adjustments or get help from a baby sleep consultant!

When It Feels Like You’re Always in a Regression

If it seems like your baby’s sleep is always a struggle, it might not actually be a regression. While it’s normal for sleep to have ups and downs, you should still have periods where naps are consistent and nights are mostly restful.

That’s where baby sleep coaching can help. A personalized sleep plan can take away the guesswork (because I know it feels like you’re tried everything!) and get you back on track quickly. 

If you’re ready for a clear, step-by-step plan to get back on track, you can learn more about our consultations here!