Changes are commonly reported around several developmental stages, but timing and duration vary substantially. Keep safe-sleep basics independent of the pattern, use routines only when they help your family, and seek clinical advice if sleep changes accompany illness or concern you.
Glossary
Sleep regression
“Sleep regression” is a caregiver label for a stretch of more broken sleep, extra wakings, or shorter naps; the pattern itself does not identify a cause.
Related guides
The 4-month sleep change
Around four months your baby's sleep grows up — more wakings now are usually a sign of healthy brain development, not a step backwards.
The 8–10 month sleep wobble
Around 8 to 10 months, big motor leaps and separation anxiety can shake up sleep that had settled — it's developmental, and it passes.
Related terms
General information, not medical advice. For concerns about your child, talk with your doctor or child-health nurse.