Baby sleep changes quickly and unevenly. This guide uses broad seasons because official guidance supports variation rather than fixed regression weeks.
Birth to around 3 months
Newborn sleep is spread across day and night in short stretches. Feeding and comfort needs are frequent, and a day–night rhythm is still developing. The useful goal here is not a schedule. Focus on safe, responsive care and enough support for the adults too.
Around 3 to 6 months
Some babies begin to sleep for longer stretches. Others continue to wake often. New movement, feeding changes and ordinary variation can all alter a week without that week being a universal “regression.”
Around 6 to 12 months
NHS guidance notes that some babies may no longer need night feeds, while hunger and teething can still disturb sleep. New skills and stronger awareness of a caregiver’s absence may also change settling from night to night.
Waking frequency is not a measure of your parenting or your baby’s development. If sleep is affecting safety, feeding, health or your ability to cope, ask a qualified professional for individual support.
Why we do not publish a regression calendar
Popular calendars assign disruption to precise ages such as “the four-month regression.” A precise week suggests a level of prediction that the sources do not provide. On the timeline, sleep therefore appears as broad change bands with plain-language uncertainty.
Keep safety guidance local and current
Safe-sleep advice is safety-critical and can be updated. Follow the current official guidance for your country and the advice of a professional who knows your baby, especially if your baby was born early or has a health condition.