Sleep changes around four months: Adjusting Expectations and Routines

A baby who previously slept a longer stretch may begin waking more often around four months. Parents often call this a sleep regression. The label describes an experience, but it does not tell you why your particular baby is waking or how long the change will last.

Development does not follow a fixed sleep calendar

Sleep organisation changes during infancy, with more regular cycles emerging around this age. That does not mean every baby has the same difficult week or suddenly becomes ready to sleep through the night.

Look at what has changed for your baby. Are feeds different, naps shorter or evenings busier? Our baby nap guide can help you notice the pattern without trying to impose an exact timetable. Keep a few simple observations rather than searching for a date when the phase must end.

Check needs before changing the routine

Offer milk in response to hunger and follow any individual feeding plan. Waking at this age can still include a need for night feeds. Do not assume that reaching four months means feeding overnight should stop.

Extra waking alone is not a sign that your baby is ready for solid food. Do not introduce solids as a sleep treatment. Readiness for complementary feeding is a separate question, usually considered around six months with appropriate developmental signs and advice for your baby.

If feeding has become painful, difficult or noticeably less effective, seek help rather than treating the resulting unsettled nights as a behaviour problem.

Make one manageable adjustment

Choose something you can repeat, such as a quieter final part of the evening or sharing one settling period with another adult. Keep nights calm and let daytime include ordinary light and activity.

You may try placing your baby down drowsy but awake when it suits them, but this is not a test they must pass. Comforting a baby who needs help does not spoil them. Our night waking guide covers feeding, comfort and caregiver support in more detail.

Recheck the sleep setup as movement changes

Continue placing your baby on their back on a firm, flat, clear surface. Stop swaddling at the first attempts to roll, even if they have not completed a roll. The rolling during sleep guide explains the difference between starting position and a baby moving independently.

Do not add pillows, positioners or weighted bedding because settling has become harder. Keep a separate sleep space nearby and avoid sleeping with your baby on a sofa or armchair.

Do not let the label hide illness

Breathing difficulty, unusual floppiness, blue or grey colour or difficulty waking needs emergency help. Seek prompt advice for poor feeding or a baby who seems unwell. A sleep change can be ordinary development, but that explanation should never replace checking concerning symptoms.