The 4-Month Sleep Regression – Why It Hits So Hard (and What You Can Do)

The 4-Month Sleep Regression – Why It Hits So Hard (and What You Can Do)

If your baby suddenly stops sleeping through the night around the 4-month mark, you’re not alone. The 4-month sleep regression is one of the most disruptive stages for new parents – and it hits harder than most expect.

What Happens at 4 Months?

At around four months, a baby’s sleep pattern matures from newborn-style "deep sleep" into distinct cycles – much like adults. This shift is completely normal but means they now wake more easily between light and deep sleep. Suddenly, a baby that slept for hours might wake every 45 minutes.

These changes are permanent. Your baby won’t go back to newborn-style sleep. But that’s a good thing in the long term. Once they learn to connect sleep cycles, longer stretches of rest become the norm again.

Why It Feels So Tough

Just as things start to feel more settled, the regression arrives. Parents who had just begun to recover from the chaos of the newborn stage suddenly find themselves waking every hour and struggling to settle their baby again.

On top of that, babies are often fussier, clingier, and harder to soothe during the day too. It’s no wonder many families feel blindsided.

Common Signs of the 4-Month Sleep Regression

  • Frequent night wakings

  • Short naps (30 minutes or less)

  • Increased fussiness or clinginess

  • Trouble falling asleep independently

  • More night-time feeds or restlessness

What You Can Do to Cope

  1. Stick to a routine: A consistent bedtime routine is your best tool. It helps signal to your baby that sleep is coming.

  2. Practise self-settling: If your baby wakes, give them a few moments before intervening. They might surprise you and fall back asleep on their own.

  3. Use sleep aids wisely: White noise, dark rooms and swaddles (if age-appropriate) can support sleep without creating long-term habits.

  4. Stay flexible: Understand that this is a phase. Offer comfort when needed, and be gentle on yourself.

  5. Don’t introduce habits you’ll want to break later: Avoid rocking or feeding to sleep every time unless you're okay continuing it long term.

When Will It End?

Most 4-month sleep regressions last 2 to 6 weeks. While it may feel never-ending in the moment, this is a normal stage in your baby’s development.

You haven’t done anything wrong. This isn’t a step backwards. It’s a sign that your baby is growing exactly as they should.

And remember – sleep will return.

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