Baby sleep: how to help them sleep well from 0 to 12 months?

The baby sleep is one of the major concerns for new parents — and often the primary source of exhaustion. At what age does a baby sleep through the night? How do you establish good habits? What should you do about night waking? This comprehensive guide on the baby sleep answers all your questions, month by month. 🌙

🧠 How does baby's sleep work?

The baby sleep is fundamentally different from adult sleep. A baby has shorter sleep cycles (45-50 minutes compared to 90 minutes for an adult), with a much greater proportion of active sleep (the equivalent of REM sleep). This active sleep is essential for their neurological development — never interrupt it.

What this means in practice: baby wakes up naturally between cycles. Their ability to fall back asleep on their own – what specialists call 'self-soothing» – develops gradually, often between 3 and 6 months. Before then, waking up is normal and doesn't mean anything is wrong.

📅 Baby sleep month by month

0 to 3 months: chaos (normal)

A newborn sleeps 16 to 20 hours a day in small stretches of 2 to 4 hours, with no day/night distinction. Their biological clock is not yet programmed. Waking up every 2 to 3 hours at night is normal and necessary — the baby needs to feed frequently. No routine is possible before 6 to 8 weeks.

3 to 6 months: the first regularities

The day/night rhythm is starting to settle in. Baby sleeps 14 to 16 hours, with longer periods of night-time sleep (sometimes 4-6 consecutive hours). This is a good time to start a simple evening routine. The first naps are beginning to stabilise (morning, midday, late afternoon).

6 to 9 months: the 6-month regression

Paradoxically, the baby sleep can deteriorate at 6 months even though it was improving. This is the «6-month regression» — linked to a major developmental leap (motor skills, cognition). It lasts 2 to 6 weeks and resolves on its own. Maintain the routine, stay the course.

9 to 12 months: towards sleeping through the night

Many babies (not all) sleep through the night by 9-12 months. 2 naps a day (morning and lunchtime). Total sleep: 13-15 hours. The 9-month sleep regression (linked to separation anxiety and motor development) can temporarily disrupt established habits.

🌙 Bedtime routine: the key to baby's sleep

The evening routine is the most effective tool for improving the baby sleep. It signals to baby that night is coming and prepares their brain for sleep. A good routine:

  • Start at the same time each evening (ideally between 7 pm and 8:30 pm)
  • Takes 20 to 40 minutes
  • Always takes place in the same order
  • Ends in the nursery

Example of an effective routine: a lukewarm bath → massage → pyjamas → breastfeeding or bottle feed → a song or story → comfort toy → off to bed.

The nightlight: an ally of the routine

Soft lighting during the evening routine (and turned off or very dim for the night) signals to baby the transition to sleep. Choose a nightlight with a warm light (amber or orange) that does not disrupt melatonin — no blue or white light for the evening.

View PetitMaxou baby night lights

🛏️ Safe sleeping for babies

Sudden infant death syndrome (SIDS) is the leading cause of mortality between 1 and 12 months. Official recommendations for a safe baby sleep :

  • On the back - always, until baby rolls over by themselves
  • Bed in the master bedroom — ideally up to 6 months
  • Firm surface — suitable mattress, without topper or cushion
  • No toys in the bed — no cot bumper, no soft toy, and no blanket before 12 months
  • Sleeping bag instead of blankets — suitable for the room temperature
  • Bedroom temperature 18-20°C
  • No smoking in baby's environment

😴 Helping baby to fall asleep on their own

Self-soothing develops naturally — you cannot force it before a baby's brain is ready (generally, not before 4-6 months). A few approaches:

The progressive method (modified Ferber method)

Put baby down drowsy but awake. If they cry, wait a few minutes before intervening, then gradually increase the interval. Reassure without picking them up. Controversial but effective for some babies from 6 months onwards.

The «no cry» method (Harvey Karp, Elizabeth Pantley)

Gradually reduce sleep associations (breast, bottle, arms) by replacing them with other routines. Slower but tear-free. Suitable for families who do not want to let their child cry.

Safe co-sleeping

Sharing the parental bed while following strict safety rules (no alcohol, no medication, firm surface, no thick duvet). Makes night-time breastfeeding easier. Not recommended before 3 months and for premature babies.

🔄 Sleep regressions: what you need to know

Sleep regressions are periods when the baby sleep — which was improving — suddenly deteriorates. They systematically correspond to a developmental leap:

  • 4 months restructuring of sleep cycles (the most difficult)
  • 6 months motor and cognitive leap
  • 9 months separation anxiety
  • 12 months walking and language
  • 18 months vocabulary explosion

Sleep regressions last for 2 to 6 weeks. The most effective strategy: maintain the routine, increase daytime cuddles, and wait it out.

❓ FAQ — Baby sleep

At what age does a baby sleep through the night?

The medical definition of «sleeping through the night» is 5-6 consecutive hours of sleep. Some babies manage this by 3-4 months, while others do not until 12-18 months. The average is around 6-9 months. There is no universal «normal» age — it all depends on the baby, feeding and temperament.

My baby only sleeps in my arms – how do I change that?

This is a classic sleep association. To change it gradually: start by putting baby down asleep in the cot, then drowsy, then increasingly awake over several weeks. Go at your own pace — there is no rush to change an association that works if you are comfortable with it.

Does a dummy help a baby sleep?

Yes — sucking is soothing, and a dummy is even recommended to reduce the risk of SIDS. If baby falls asleep with the dummy and wakes up when it falls out, you can put several in the cot around 6-8 months so they can find one on their own.

Does a baby need to sleep in complete darkness?

For daytime naps, darkness makes sleep easier but is not essential. For the night, complete darkness (or a very dim amber nightlight) is ideal to encourage melatonin production. Avoid white or blue nightlights, which disrupt falling asleep.

🛍️ Create a sleep-friendly environment at PetitMaxou

Gentle night lights, cot accessories, safe doudous: PetitMaxou offers everything you need to help your baby sleep soundly. Free delivery throughout the EU, returns within 14 days.

→ See the PetitMaxou nursery

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