Baby sleep at 3–4 months: something has changed (and you're not imagining it)

Something has changed, and you're not imagining it!

Around 3–4 months, one of the biggest shifts in your baby's sleep takes place – the sleep stage flip.

What does this mean, and how does it affect sleep?

Up until now, your baby would enter sleep through relatively light sleep, and move into deeper sleep toward the end of the sleep cycle. Now the pattern is changing, and the foundation for more mature sleep stages starts to develop – baby enters sleep through deep sleep, and moves into lighter sleep toward the end of the cycle. This is why it's suddenly harder to put him down after 20 minutes (even though it worked like a charm until now 😊), and why he wakes between sleep cycles.

Everything is more interesting now

Generally speaking, your baby is also becoming more aware of everything going on around him – light, people, noise. This can also make it harder for him to focus while feeding, and it can feel like “he's rejecting me,” when really, he's just curious. So what can you do? If you're at home, try feeding in a dark, quiet room. If you're out and about, you can try covering baby to help him focus on feeding without distractions around him.

The leap around week 17

There's also a developmental leap around week 17 – baby starts rolling, or shows signs of getting there, and his little brain is working overtime during these periods, which can cause more frequent wake-ups. It's not a bug! It's a feature.

Generally, night wakings at this age are still completely normal, and there's no “problem” with your baby whatsoever.

Day and night

This is the stage where the body starts developing a body clock, so now's the time to create a clear difference between day and night – natural light during the day, dark and dim lighting at night.

About night feeds

I do want to clear something up, because I keep coming across claims that at this age waking to feed is just a “habit” that needs to be broken – let me be clear: babies still need feeding at night up until age one. Their calorie intake works differently to ours, and they need breastmilk/formula at night too. I get that you're exhausted, but your baby still needs to eat.