Why does my baby roll one way but not the other?

Rolling at four months, one direction only

She was rolling from back to tummy easily, both sides, and couldn't get back again.

We asked how long that usually takes, and the honest answer is that it's normal and it can be several weeks. Sometimes longer.

The harder one comes first

That seems backwards and it isn't. Back to tummy uses a push and a twist that babies develop earlier. Tummy to back needs a different set of muscles and a bit of weight-shifting that takes longer to work out.

So the common pattern is: she learns to roll onto her front, immediately does it in her cot at two in the morning, and then lies there furious because she can't undo it.

That phase is genuinely annoying and it passes.

What changes the moment she rolls at all

Swaddling stops. Not when she rolls reliably — at the first sign. A swaddled baby who ends up on her front can't use her arms, and that's the situation to avoid entirely.

The cot stays completely empty. No positioners, no rolled towels, nothing to stop her turning.

And you still put her down on her back every time. Once she can roll herself, you don't need to keep turning her back over through the night — but she goes down on her back.

A sleeping bag rather than a blanket makes all of this simpler.

Practise it in daylight. Lay her on her front, put something interesting off to one side, and let her work at it. Guide her hip gently if she's stuck, rather than doing it for her.

Floor time, more of it than feels necessary. Babies parked in seats and bouncers simply don't get the reps.

And expect one side to come before the other. Ours rolled beautifully to one side and hopeless to the other for a while, which is entirely usual.