Can the 4 month regression happen at 3 months?

Here’s a fun fact for you: the 4 month regression is a permanent change to your baby’s sleep cycles. As a newborn, they cycled through light/active or deep/quiet sleep (so 2 sleep cycles) and as an adult with mature sleep cycles, they have 4 sleep cycles (which means more opportunities for light sleep/waking up).

This is the *only* developmental change that happens to sleep and it’s not like normal regressions where sleep returns to their “normal” after a few weeks. Their sleep may improve from waking every sleep cycle, but their sleep doesn’t actually return to its previous state like the term regression implies.

So can the 4 month regression happen at 3 months?!

YES 😩

The 4 month regression can actually begin any time after their circadian rhythm is developed, which is fully formed by 12 weeks of age. It can also happen as late as 5-6 months. 

If you’re wondering if you’re in the clear, just know that not every regression impacts a baby’s sleep. While their sleep cycles WILL change and mature, it doesn’t mean it’ll affect their sleep in any way (or maybe it only impacts naps and not nights, for example).

To learn more about the 4 month regression, check out this blog!

And if you’re wondering if you can sleep train through a regression/or sleep train at any age, check out this blog then set up a free chat to find the perfect support package for your situation!