4 Month Sleep Regression (Progression): What Every Parent Needs to Know

Sarah Patel
Jun 5, 2024
2 min read

Updated: Oct 18

baby during the 4 month regression (progression) being upset

Many parents worry about the 4 month sleep regression and how it will affect their baby’s sleep. Understanding what’s happening and how to respond can make this challenging phase much easier for both you and your baby.

What is the 4 Month Sleep Regression?

The 4 month sleep regression is a normal developmental phase when a baby’s sleep cycles mature and become more adult-like in structure. Some experts, like Lyndsey Hookway, refer to it as a sleep progression rather than a regression—because while sleep may seem disrupted, your baby’s sleep is actually moving forward developmentally.

When Does the 4 Month Sleep Regression Happen?

Typically occurs around 4 months of age
Can happen as early as 3 months or as late as 6 months

How Long Does the 4 Month Sleep Regression Last?

The 4 month sleep regression usually lasts 2–6 weeks, depending on your baby’s temperament:

Sensitive babies may take longer to adjust
Less sensitive babies may adapt quickly or hardly notice changes

Signs Your Baby is Going Through the 4 Month Sleep Regression

You might notice the following behavioural changes:

Difficulty falling asleep
Waking after short periods
Resisting naps
More difficulty settling for bedtime
Less interest in daytime feeds
Needing more night feeds
Being more unsettled during the day and night
Clinginess and not wanting to be put down
Usual methods like rocking or feeding may not easily settle your baby

Not All Babies Are Affected by the 4 Month Sleep Regression

Some babies sail through this phase without any sleep disruption. Try not to dread the 4 month regression—your baby may adjust smoothly!

How to Support Your Baby Through the 4 Month Sleep Regression

If your baby struggles with these changes, it’s time to “lean in” and offer extra support:

Offer contact or on-the-move naps if your baby settles better that way
Consider safe bedsharing to help both parent and baby get more sleep
Provide extra support to fall asleep, including soothing techniques
Offer more feeds during the night or day as needed
Increase skin-to-skin time to comfort your baby

Remember: self-soothing cannot be taught at this stage, and leaving your baby to cry may be counterproductive.

Personal Experience of the 4 Month Sleep Regression

Both of my babies were very sensitive to the 4 month progression—they woke every 45 minutes at night! It was exhausting, but they both eventually adjusted. If you’re going through something similar, know that you are not doing anything wrong—this is a normal developmental phase that will improve.