How long does a sleep regression last?

Between 2 and 6 weeks in most cases. Keep the schedule and the usual way of falling asleep, and sleep tends to settle back on its own. If it lasts longer, something else is usually going on: a pending nap transition, misaligned wake windows or a new habit that has stuck.

Does every baby go through every regression?

No. Some babies hit all of them clearly and others barely flinch. The only near-universal one is the 4 month regression, because it’s a change in sleep architecture, not a phase.

What should I avoid doing during a regression?

Changing everything. Suddenly introducing hard-to-remove habits (a car nap every day, unplanned co-sleeping, stretching the routine to an hour) tends to prolong the dip. Better to keep the structure and add temporary extra comfort.

How do I tell a regression from a schedule problem?

A regression hits suddenly in a baby who slept well and coincides with developmental leaps. A schedule problem builds up gradually: naps or bedtime get a little harder every week. For the latter, review the wake windows for their age.

Siestita Guide

Sleep regressions: when they arrive and what to do

Your baby was sleeping well and, overnight, nights fill with wakings and naps go on strike. Welcome to the sleep regression: a temporary dip tied to a developmental leap. Annoying, but it follows a known script.

What is a sleep regression?

A sudden, temporary worsening of sleep in a baby who was sleeping well, triggered by a developmental leap: new motor skills, language, separation anxiety or changes in sleep architecture. The brain is so busy learning that it “rehearses” at night too.

The general recipe for all of them: keep the schedule and the wake windows for their age, keep the bedtime routine, add extra comfort without dismantling the usual habits, and wait — most last 2 to 6 weeks.

The regressions, one by one

The 4 months regression

The only “permanent” regression: your baby switches to adult-like sleep cycles. More wakings, broken naps and a very tired household. It has its own full guide.

Full 4 month regression guide →