The 8-to-10-month sleep regression

Medically-informed · Sources: AAP, CDC · Updated July 2026 · 3 min read

A different animal than 4 months

The 4-month shift rebuilt sleep architecture permanently. This one is simpler and kinder: a temporary collision of three big developments. Your baby just acquired motion (crawling, pulling up), a working memory of you (separation awareness peaks in this stretch), and often a nap schedule in mid-renovation. The brain rehearses new skills at night, the body pops into standing at 2 AM without knowing how to get down, and the heart objects loudly to your exit. Typical run: two to six weeks, then sleep returns to its previous baseline — because unlike at 4 months, nothing structural changed.

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What it looks like

Sudden night wakings in a formerly solid sleeper, crib gymnastics at bedtime, a baby standing in the dark holding the rail like a tiny night watchman, nap refusal — usually the third nap dying on schedule — and dramatic protest at goodnight that ends fast once you leave. Cheerful days, chaotic nights: that combination is the signature of a developmental regression rather than illness.

Is this normal for your baby?

FirstWeeks answers with your baby’s age and today’s log in mind — with pediatric sources attached.

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What steadies it

Give the skills a daytime gym: lots of floor practice pulling up and — critically — sitting back down, so the 2 AM standing trap has an exit your baby knows. Keep bedtime boring and identical; this is the worst possible fortnight to renovate the routine. Handle wakings with minimum viable comfort — brief, low-light, low-drama — and resist importing new habits (a rocking-to-sleep service launched during a regression tends to outlive it by months). For the separation piece, an extra dose of unhurried together-time before bed pays back at night.

What not to do

Don't drop to one nap because naps got messy — at this age that usually backfires into overtiredness. Don't test three strategies in three nights; nothing gets a fair trial. And don't benchmark against the baby next door whose regression lasted four days.

When to check in

See your pediatrician if wakings come with fever, ear-pulling plus crying, breathing changes, feeding refusal, or if weeks pass with zero improvement — ear infections and reflux both audition for the role of "regression" convincingly. Bring the sleep log; the pattern across two weeks answers questions memory can't.