Is your baby suddenly waking up at night after sleeping well? Learn about the causes and symptoms of 4-month sleep regression and effective strategies to get through it.

What is the 4-Month Sleep Regression?

The 4-month sleep regression is a temporary disruption in sleep patterns that typically occurs between 3-5 months of age. Your previously good sleeper may suddenly wake frequently at night, take shorter naps, and seem generally more unsettled.

This period marks an important developmental milestone as your baby's brain matures and their sleep cycles transition to adult-like patterns. While challenging, it's actually a sign of healthy development.

Signs of 4-Month Sleep Regression

Nighttime Signs

Waking every 2-3 hours
Taking longer to fall asleep
Fully waking in the early morning
Only falling asleep when held

Daytime Signs

Short naps (30-45 minutes)
Irregular nap schedule
Difficulty settling for naps

Behavioral Changes

Increased fussiness
Distracted during feeds
Fighting sleep despite being tired

Why Does the 4-Month Sleep Regression Happen?

1. Sleep Cycle Changes

Newborns only have REM and non-REM sleep, but around 4 months, babies develop 4-stage sleep cycles like adults. This transition causes more frequent wake-ups between cycles.

2. Brain Development

Your baby's brain is developing rapidly during this time. Processing new information and skills can overwhelm their system, affecting sleep.

3. Physical Development

Learning new skills like rolling over and discovering their hands makes babies want to practice instead of sleep.

4. Circadian Rhythm

Melatonin production stabilizes, establishing day-night rhythms.

How to Survive the 4-Month Sleep Regression

Create a Consistent Bedtime Routine

A predictable bedtime routine signals to your baby that sleep is coming.

Sample Routine:

Bath time (15 minutes)
Massage & lotion (5 minutes)
Pajamas
Feeding (in dim room)
Lullaby or white noise
Into crib

Optimize the Sleep Environment

Dark room: Use blackout curtains
Cool temperature: 68-72°F (20-22°C)
White noise: Mimics womb sounds
Safe sleep space: Firm mattress, empty crib

Put Baby Down Drowsy But Awake

If you always put your baby down fully asleep, they'll be confused when they wake up in a different situation. Practice putting them down drowsy but still awake to help them learn to self-settle.

Manage Daytime Sleep

Age	Number of Naps	Total Nap Time	Wake Window
3 months	4-5	4-5 hours	1-1.5 hours
4 months	3-4	3-4 hours	1.5-2 hours
5 months	3	3-3.5 hours	2-2.5 hours

How Long Does It Last?

The 4-month sleep regression typically lasts 2-6 weeks. Every baby is different, and some may experience shorter or longer disruptions.

Tips for Getting Through:

Stay consistent with routines
Avoid overstimulation
Ensure adequate daytime feeds
Take care of yourself too

Track Sleep Patterns with BebeSnap

During the 4-month sleep regression, tracking your baby's sleep patterns is crucial. Use BebeSnap to easily log sleep times and review weekly reports to monitor changes.

Sleep tracking helps you:

Find optimal bedtime
Analyze nap patterns
Track regression duration
Monitor improvements

👉 Learn more about BebeSnap Sleep Records

FAQ

Q: Do all babies experience the 4-month regression? A: No, not all babies show noticeable sleep regression. About 30% pass through without significant changes.

Q: Should I start sleep training? A: Starting during the regression isn't recommended. Wait until things settle, usually around 5-6 months.

Q: Should I increase night feeds? A: If baby seems hungry, feed them. Just ensure adequate daytime feeds to prevent habit forming.

References

Complete Guide to 4-Month Sleep Regression: Causes, Signs & Solutions