4 Month Sleep Regression Explained: Causes & Recovery Plan

Editor: Suman Pathak on Jun 20,2025

 

For many new parents, the early weeks of babyhood often come with sleepless nights, short naps, and constant adjustments. When it seems like your baby is finally settling into a routine, everything changes again. Around 4 months, many babies suddenly begin waking more at night, taking shorter naps, and fighting sleep altogether. This change is known as the 4-month sleep regression.

If your baby is not sleeping at 4 months old like they used to, you are not alone. This phase is a common and temporary part of infant development. Let’s dive into what the 4-month sleep regression is, why it happens, how long it usually lasts, and a recovery plan for baby sleep regression.

What is the 4 Month Sleep Regression?

The 4 month sleep regression is a developmental phase where a baby’s sleep patterns change permanently. Newborns sleep deeply and often, but by four months, their sleep cycles start to look more like those of an adult, cycling through light and deep sleep.

This change can cause your baby to wake more often at night and resist naps during the day. You might notice that your once peaceful sleeper is suddenly restless, cranky, or crying more often, especially at bedtime.

Parents often worry when their baby is not sleeping at 4 months old, after a few weeks of better rest. But it’s important to understand that this phase is a sign of healthy brain development.

Common Signs of the 4 Month Sleep Regression

Not all babies go through this phase the same way, but typical signs include:

  • Waking up more often at night
  • Shorter naps or difficulty falling asleep
  • Increased fussiness or irritability
  • Seeming tired but unable to stay asleep.
  • Feeding more frequently during the night

These changes can happen suddenly, and the first instinct for many parents is to assume something is wrong. In most cases, though, this is just a normal adjustment period.

Causes of the 4 Month Sleep Regression

Understanding what’s causing the regression can help you cope with it. Here are the most common triggers:

1. Maturing Sleep Cycles

Your baby is developing adult-like sleep cycles with light and deep stages. This means they now wake up more easily.

2. Increased Awareness

At four months, babies become more aware of their surroundings. Sounds, lights, and new faces can all disrupt sleep.

3. Physical Growth and Development

Rolling over, increased movement, and growing muscles may make your baby more restless.

4. Changes in Feeding Patterns

A growth spurt may cause your baby to want more milk or formula, especially during the night.

5. No Established Routine

If a consistent 4-month-old sleep schedule hasn't been created yet, the regression may feel more intense.

How Long Does the 4 Month Sleep Regression Last?

A very common question from parents is about the duration of sleep regression at 4 months. Thankfully, this phase doesn’t last forever. On average, it lasts about 2 to 6 weeks.

However, the exact sleep regression duration at 4 months can vary depending on the baby’s temperament, environment, and how quickly a stable sleep routine is established.

This is a transitional period, and while it may feel long and exhausting, the sleep disruption usually settles down within a few weeks. Knowing this can help parents stay calm and focused on a solution.

Newborn girl sleeps

Step-by-Step Recovery Plan for Baby Sleep Regression

Creating a recovery plan for baby sleep regression can make a big difference in how quickly your little one returns to more restful nights. Here’s a simple plan that many parents find helpful:

Step 1: Establish a Consistent Bedtime Routine

Babies feel secure with structure. A calming routine helps signal that it’s time to sleep.

  • Start with a warm bath.
  • Dim the lights and reduce noise.
  • Feed your baby in a quiet room.
  • Read a short book or sing a lullaby.
  • Try to put your baby down drowsy but awake.

Doing this at the same time every night will help set internal cues for sleep.

Step 2: Create a Sleep-Friendly Environment

A comfortable and quiet sleep space is key:

  • Use blackout curtains to block light.
  • Keep the room cool and quiet.
  • Use white noise if outside sounds are disturbing.
  • Choose a firm, safe sleep surface.

Avoid overstimulation right before bed, and remove distractions like toys from the crib.

Step 3: Follow a Daytime Sleep Schedule

A regular 4-month-old sleep schedule usually includes:

  • 3 to 4 naps during the day
  • Wake windows are between 1.5 and 2 hours.
  • Bedtime is around 7:00 to 8:00 PM

Try to be consistent with nap times. Too much or too little daytime sleep can affect nighttime sleep.

Step 4: Avoid Over-Tiredness

When a baby is not sleeping at 4 months old, they often become overtired, making it even harder for them to fall asleep.

Watch for early sleepy cues like:

  • Rubbing eyes
  • Yawning
  • Looking away from you
  • Fussiness

Putting your baby down at the first signs of tiredness increases the chance of easy sleep.

Step 5: Feed Adequately During the Day

Ensure your baby gets enough milk or formula throughout the day so they don’t rely heavily on night feedings. This may help reduce the number of night wakings caused by hunger.

Step 6: Let Baby Settle Themselves (If Possible)

Learning how to fall asleep on their own is a crucial milestone. While it’s okay to comfort your baby when needed, giving them a few minutes to try settling themselves can help in the long term.

Step 7: Offer Comfort but Be Consistent

It’s natural to want to soothe a crying baby, especially at 2 a.m. But during this phase, consistency is essential.

If you always rock or feed your baby to sleep, they may rely on that to fall back asleep. Try other calming techniques, like gentle pats or soothing words, and gradually reduce assistance over time.

When Will Sleep Return After the 4 Month Regression?

Many parents ask, “When will sleep return at 4 months?” The good news is, most babies start sleeping better again once they adjust to their new sleep cycles and routines.

If you follow a consistent sleep plan and respond to your baby’s needs with calmness and patience, you will likely see improvement in 2 to 6 weeks.

The key is to not introduce too many new sleep habits that you don’t want to keep in the long term—like rocking to sleep every time or constant night feeding unless needed for nutrition.

What If It Doesn’t Get Better?

If your baby’s sleep continues to be difficult beyond 6-8 weeks, consider the following:

  • Talk to your pediatrician to rule out any medical issues
  • Re-evaluate the nap and bedtime schedule
  • Look into gentle sleep training techniques if appropriate
  • Seek support from a sleep consultant.

Every baby is different, and while the sleep regression duration at 4 months is often short, some little ones need extra time and guidance.

Bonus Tip: Don't Ignore Self-Care for Parents

Through coping with the **4 month sleep regression**, your own needs can easily be forgotten. Strive to sleep while your baby naps, eat well, and appreciate help when offered. A well-rested parent has a better chance at supporting their baby. This is just a temporary phase—take care of yourself, too.

Final Thoughts

The 4 month sleep regression is a frustrating but highly normal time of your infant's development. As annoying as it is when your baby refuses to sleep at 4 months old, it's also a sign of enormous brain growth.

Keep in mind, this won't last forever. Your baby will soon begin to adjust, and sleep will return to your home. If you are asking, "When does sleep come back at 4 months?" just know that most families will begin to see more restful nights in just a few weeks with the proper support and plan.


This content was created by AI