Sleep regression: why and when it happens
A baby who was sleeping well and suddenly starts waking up often — here's what's going on and how to get through it.
A sleep regression is a stretch, often a few days to a few weeks, during which a baby who had good sleep habits starts waking frequently at night or resisting naps again. The most commonly reported windows are around 4 months, 8-10 months, and 18 months, though this isn't universal or fixed in time.
These regressions often coincide with major developmental leaps: at 4 months, the maturing of sleep cycles themselves; later on, learning new motor skills (crawling, walking) or separation anxiety, all of which can temporarily disrupt sleep.
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During this period, keeping your usual bedtime routine — even if it takes longer or needs more patience — generally helps get through the phase faster than changing everything at once. Offering a bit more comfort temporarily won't create a permanent 'bad habit.'
The good news is that most regressions resolve on their own within 2 to 6 weeks, once the underlying development has stabilized. If sleep struggles persist well beyond that, or come with other concerning signs, it can be worth discussing with your healthcare provider.
This information is general and does not replace advice from your healthcare professional (doctor, midwife, nurse, pharmacist). Every situation is unique: always check with them before making a decision. In an emergency, call 911 or your local emergency services.
