The 4-Month Sleep Regression: Why It Happens & How to Get Through It

If your once-sleepy newborn has suddenly started waking up frequently at night, taking short naps, and fighting sleep, you may be in the middle of the dreaded 4-month sleep regression. This phase can be exhausting for parents, but the good news is that it’s temporary—and there are effective ways to help your baby sleep better during this time.

What is the 4-Month Sleep Regression?

The 4-month sleep regression is a developmental milestone that occurs when a baby’s sleep patterns permanently change. Unlike newborn sleep cycles, which are short and unpredictable, around four months, babies transition into a more adult-like sleep pattern. This means they cycle through light sleep and deep sleep more distinctly, causing frequent wake-ups as they adjust to this new rhythm.

Signs of the 4-Month Sleep Regression

• More frequent night wakings (every 1-2 hours)

• Short naps that last 30-45 minutes

• Difficulty falling asleep at bedtime

• Increased fussiness and overtiredness

• Resistance to being put down for sleep

These changes can be frustrating, but they’re a sign that your baby is growing and developing normally!

How Long Does the 4-Month Sleep Regression Last?

The sleep regression typically lasts 2 to 6 weeks, depending on your baby’s ability to adapt. If good sleep habits are encouraged, your baby will adjust more quickly.

How to Help Your Baby Sleep Better During the 4-Month Sleep Regression

While you can’t “skip” the sleep regression, you can make it easier by setting up healthy sleep habits that will last well beyond this phase.

1. Establish a Consistent Bedtime Routine

Babies thrive on routine, and a predictable sequence of calming activities before bed helps signal that it’s time to sleep. Try the following steps:

• Bath time (if it relaxes your baby)

• Gentle massage

• Feeding (but not always as the last step)

• Reading a book or singing a lullaby

• Dimming the lights and using white noise

A routine like this helps create a sleep association, making it easier for your baby to settle down at bedtime.

2. Encourage Independent Sleep Skills

One of the main reasons babies struggle during the 4-month sleep regression is that they rely on external help (rocking, nursing, or holding) to fall asleep. When they wake up at night, they need the same help to fall back asleep.

To encourage self-soothing, try putting your baby down drowsy but awake so they learn to settle themselves. This won’t work overnight, but consistent practice helps babies become independent sleepers.

3. Optimize the Sleep Environment

Make sure your baby’s sleep environment is dark, cool, and quiet:

• Use blackout curtains to block out light.

• Set a comfortable room temperature (68-72°F is ideal).

• Use white noise to drown out sudden noises that might wake your baby.

• Ensure your baby is in a safe sleep space—a firm mattress with no blankets, pillows, or toys.

4. Watch for Sleep Cues and Avoid Overtiredness

Overtired babies have a harder time falling and staying asleep. Signs of tiredness include:

• Rubbing eyes

• Yawning

• Decreased activity

• Fussiness

When you see these signs, start the nap or bedtime routine right away. Babies at this age do best with wake windows of 1.5 to 2.5 hours before needing sleep.

5. Introduce a Lovey (If Safe)

While soft toys and blankets are not safe for sleep before 12 months, you can introduce a sleep association object like a small muslin cloth or a parent’s scent on a piece of fabric to provide comfort.

6. Feed Well During the Day

Hunger can contribute to night wakings. Make sure your baby is getting full feedings during the day to reduce the need for extra nighttime feeds.

7. Be Patient and Stay Consistent

It’s tempting to try new solutions every night, but babies thrive on consistency. Stick to your routine, avoid developing new sleep crutches, and remember—this phase will pass!

When to Seek Additional Help

If your baby’s sleep regression lasts longer than 6 weeks, or if sleep disruptions are severe, you may benefit from working with a baby sleep consultant. Professional guidance can help customize a sleep plan suited to your baby’s needs.

Final Thoughts

The 4-month sleep regression is tough, but it’s also an opportunity to set a foundation for healthy sleep habits. With the right strategies, your baby will soon learn to sleep longer and more peacefully. Stick to a consistent routine, encourage independent sleep, and create a calming sleep environment—and better sleep will follow!