Sleep guides · Baby & infant
Sleep regressions:what's actually happening.
Sleep was working. Maybe not perfectly, but working — and then, in the space of a week, it wasn't. Wakings doubled. Naps shrank. Someone online told you it's the regression, and it'll pass. Someone else told you it never passes on its own.
Here's the calmer truth about regressions.
What's actually happening
The famous '4-month regression' isn't a regression at all — it's a permanent maturation. Baby sleep reorganizes into adult-like cycles, which means more junctions in the night to surface at. Babies who could already link cycles sail through it; babies who relied on being fully helped to sleep start waking at every junction.
Other regressions cluster around development: rolling, crawling, standing, language bursts, separation awareness. The skill rehearses at night; sleep temporarily frays.
Which ones pass — and which linger
Developmental bursts usually settle in one to three weeks once the skill is mastered.
The 4-month maturation doesn't reverse — but sleep can absolutely be rebuilt on the new wiring.
A 'regression' that runs six-plus weeks usually isn't a regression anymore — it's a new pattern that formed during one.
How to come out the other side
During a developmental burst: keep the structure, offer the extra comfort, practice the new skill during the day, and wait for the wave to pass. What you don't want is five new habits installed during a two-week storm.
After the 4-month shift: the work is sleep onset — helping your baby learn to fall asleep (and link cycles) with progressively less help, at a pace your family can actually hold.
When it's worth a conversation
If the wave never passed — if you're six weeks past 'it should settle any day now' — that's the moment. We'll figure out what's developmental and what's become structural, and rebuild from there.
A few things parents ask me
Do sleep regressions happen at specific ages?
The honest answer: development doesn't follow a calendar as tightly as the internet says. The 4-month maturation is real and physiological; beyond that, 'regressions' tend to track skills and changes more than birthdays.
Should I sleep train during a regression?
Mid-storm is rarely the moment to start something new. Stabilize first; then, if the underlying pattern needs work, choose a settled week and a method that fits your family. What that looks like is exactly what we can figure out together.
Tell me what happened last night.
You don’t need to have any of this figured out before we talk. I’ll ask some questions, we’ll look at what you’ve already tried, and I’ll tell you what I notice. Then you decide.