The 4-month sleep regression: a calm routine that helps
General information, not medical advice. Talk to your paediatrician about your baby’s sleep and hearing.
Somewhere around three to four months, many babies who had started sleeping better begin waking more often. Parents call it the “4-month sleep regression”. Many sleep specialists describe it as a change in how babies sleep — their sleep cycles become more like an adult's, with lighter stretches in between — rather than something going wrong. It is common, usually temporary, and a calm routine helps.
What you might notice
- More night waking and shorter naps.
- A baby who used to fall asleep easily now protests.
- Fussiness, sometimes alongside growth spurts or new skills.
A calm routine that helps
- Watch the wake windows. An overtired baby often sleeps worse. Offer the nap a little earlier if your baby shows tired signs.
- Same bedtime routine, same order. Bath, feed, story or song, lights down — the sequence itself becomes the cue.
- Dark room, comfortable temperature.
- One steady sound cue. A soft fan sound or white noise at a low volume, played the same way each time, can help your baby link the sound with sleep. Keep it quiet, keep the speaker across the room, and use a timer (safe-volume guide).
- Put your baby down drowsy but awake when you can, so falling asleep becomes a familiar skill.
How long does it last?
Families commonly report a few weeks. If your baby's sleep or feeding seems off, or you are exhausted and worried, talk to your paediatrician — they can also check for other causes of waking, such as illness or reflux.
A quick safe-sleep reminder
Sound does not replace safe sleep. Always place your baby on their back, on a firm, flat sleep surface, in an empty crib or bassinet — no pillows, blankets, bumpers or soft toys (see the AAP safe-sleep guidance). If your baby has trouble sleeping, you have hearing concerns, or anything else worries you, talk to your paediatrician.
Sources
- HealthyChildren.org (American Academy of Pediatrics) — How to keep your sleeping baby safe: AAP policy explained
- Children's National Hospital — Baby sound machines and hearing loss