Sleep between 3-6 months

Sleep between 3–6 months (including the 4-month sleep progression) 

What to expect: 

Total sleep: 14–15 hours in 24 hours 

Wake windows: 1.5–3 hours 

Naps: Usually 4 per day 

Night waking: Still normal and expected 

The 4-month progression  Between 3–5 months, your baby’s sleep cycles mature, and their total sleep needs over a 24-hour period may decrease. At the same time, your baby is developing at a rapid pace - learning motor skills like lifting their head, rolling, bringing their hands to the midline, cooing, smiling, reaching for things they want, and communicating more. All of these changes can impact sleep. 

The catch? Not all babies experience disrupted sleep at this stage. It’s easy to feel anxious as a parent about the so-called "regressions," but if your baby doesn’t go through a noticeable sleep disruption at this age, there’s no need to worry. 

Instead of stressing in advance, it’s better to understand what to look for (see below) and how to respond if changes occur. 

If your baby experiences changes to sleep around the 4-month mark due to the developmental shifts mentioned above, you may notice: 

  • Shorter naps 
  • Increased night waking 
  • Difficulty resettling between sleep cycles 

This is not a regression, and they’re not going “backwards.” It’s a permanent developmental change in their sleep architecture. Your baby is beginning to spend significantly less time in the deeper stages of sleep than they did before, and they need time to adjust to sleep feeling different. 

Your baby is not broken. They are developing. 

Parent tip for this age bracket: 

If your baby is going through sleep changes, try taking shifts overnight with a co-parent or a trusted family member or friend. This helps ensure you get at least one reliable stretch of sleep each night—even if it’s just 8 pm to midnight. 

Also, assess your baby’s overall sleep. Has their total day sleep decreased? Are you still using nap and bedtime timings that worked a couple of months ago? If so, it might be time to adjust. Your baby may need slightly longer wake periods between naps to build enough sleep pressure - and to naturally reduce the amount of sleep they need across a 24-hour period. 

Myth busting 

  • Babies cannot get “stuck” in the 4-month regression. 
  • They don’t lose the ability to self-settle, and you won’t be stuck with a “bad sleeper” just because you supported them during this time. 
  • As long as there are no red flags, and sleep pressure is balanced throughout the day (not too much or too little day sleep), then any changes that might happen at this age and stage will pass.