Why is my baby sleeping badly since learning something new?

Things were just going so well. And suddenly it's three wake-ups a night, while nothing has changed about the room, the routine or the feeding.

Then take a look at what your baby is learning during the day.

Practice continues at night

New skills come back at night. What gets practiced during the day, the brain processes and repeats during sleep, and that makes sleep more restless. That's a sign of healthy development.

Knowing that ahead saves a lot of panic: if your baby suddenly sleeps badly for no clear reason, you can often count on something new coming soon.

Which milestones hit hardest

Rolling, around four months. The biggest of all. It gets practiced in bed, and then your baby lands on the tummy with no way back. At the transition between two sleep cycles the changed position sinks in, and then loud crying follows. Then simply put your baby back on their back quickly. As soon as the way back works too, it solves itself. In detail in rolling and sleep.

Sitting, crawling, pulling up, cruising along the couch, first steps. Same pattern. Think of a baby who wakes up, sits up and no longer knows how to lie down again. Then you get called, because your baby does want to sleep, only the way there is lost.

Separation anxiety. At some point it sinks in for the first time that you can leave. For a baby that's enormous: when you walk out of the room, the idea that you'll never come back is very real. Hence the crying at bedtime. No technique helps here, only closeness: stay sitting a little longer, give extra comfort, show that you come back. More in separation anxiety and sleep.

Physical discomfort, such as teething, being sick or reflux. Give extra comfort and cuddles, chilled teething toys for teething, and otherwise keep your routine intact. This passes on its own. What teething does to the night exactly is in teething and sleep.

What else changes

In the first months there's no rhythm yet: lots of sleep, in short stretches, with day and night mixed up. Around three months the body clock has developed and night blocks can get longer. Before that, it simply isn't there.

Around four months the sleep structure itself changes, and that's the biggest of all: the four-month sleep regression. Mental leaps play a part too, see Wonder Weeks and sleep.

What you can do

1. Practice the skill during the day. This is the most important one. The better it works during the day, the less your baby stays busy with it at night.
2. Keep your bedtime routine intact. Especially now. Predictability is what's needed in a restless phase.
3. Give extra calm, comfort and closeness. This isn't the moment to force something new.
4. Prevent overtiredness and watch the tired cues. See wake windows by age.

Otherwise, stay consistent. A restless phase is a bad moment to overhaul your approach, because then confusion gets added on top of the development.