Surviving the 4-Month Sleep Regression: A Guide for Exhausted Parents

Author: Megan, Founder of The Lullaby Mummy

Welcome to the 4-Month Sleep Regression (Yes, It’s a Thing)

You’ve just gotten into the swing of things- your baby is starting to sleep longer stretches at night, you're finally feeling human again… and then suddenly, it all changes.

Naps are shorter. Night wakes ramp up. You’re Googling “Is my baby broken?” at 3 AM.

Take a deep breath, Mama. You’ve hit the 4-month sleep regression and you’re definitely not alone.

Hi, I’m Megan, founder of The Lullaby Mummy, and I’m here to walk you through what’s happening, why it’s actually a good sign (yes, really!), and how you can survive this stage without completely losing your mind (or your sleep).

What Is the 4-Month Sleep Regression?

The 4-month sleep regression is a permanent developmental shift in your baby’s sleep cycles. Around this age, your baby’s brain matures, and their sleep starts to become more like ours moving through light and deep phases of sleep.

That sounds great in theory, but in reality? It means your baby is more likely to wake between sleep cycles and they haven’t yet learned how to connect those cycles on their own.

Symptoms may include:

  • Shorter naps (20 - 40 minutes)

  • Frequent night waking

  • Increased fussiness or clinginess

  • Difficulty falling or staying asleep

Why This Is Actually a Milestone

It’s tough now, but this regression is a sign of healthy brain development.

Your baby is learning:

  • Circadian rhythm awareness

  • Sleep-cycle transitions

  • New sensory processing abilities

This shift lays the groundwork for longer, more restorative sleep later. Think of it as growing pains for sleep.

Survival Tips for the 4-Month Sleep Regression

Here’s what you can do (starting tonight) to make this phase more manageable:

1. Establish a Consistent Bedtime Routine

Babies thrive on predictability. A calming routine—like bath, feed, book, cuddle, bed—helps signal it’s time to wind down. Keep it short, sweet, and consistent every night.

2. Prioritise Day Sleep

Overtired babies wake more at night. At 4 months, your baby still needs 3 - 4 naps a day. Don’t worry if naps are short, offer them regularly and watch for sleepy cues.

3. Create a Sleep-Friendly Environment

A dark, cool, quiet room with white noise can make a huge difference. Think: womb vibes.

4. Start Teaching Self-Soothing Skills

If you're ready, this is a great age to gently introduce sleep associations that don’t rely solely on feeding or rocking. (Not sure how? I can help see below!)

5. Feed When Needed

Many 4-month-olds still need night feeds. It’s okay to respond with a feed if your baby is hungry, this regression isn’t about going cold turkey.

What Not to Do

🚫 Don’t assume you’ve “ruined” your baby’s sleep.
🚫 Don’t start drastically changing things out of panic.
🚫 Don’t ignore your baby’s needs they’re still little and learning.

When Will It End?

Most babies move through the regression in 2–6 weeks. But without the right support or routines in place, some sleep challenges can linger.

That’s where I come in.

Need Extra Support?

As a certified infant sleep consultant, I work 1:1 with families to create personalised sleep plans that work for your baby and your parenting style.

Want to fast-track better sleep?

🍼 Book a free 15-minute sleep discovery call

Final Words of Encouragement

This phase is temporary - but the habits you build now can last a lifetime.

You’re doing an amazing job. Your baby isn’t broken. And better sleep is possible, with the right tools and a little support.

Hang in there! I’ve got your back 💛

Megan x


Founder, The Lullaby Mummy

Certified Infant Sleep Consultant

Previous
Previous

How to Stop 5AM Wake-Ups: A Sleep Guide for Tired Parents

Next
Next

Nap Schedules by Age: When and How Long Should Your Baby Nap?