Baby sleep at 4 months
what really changes
Four months is the age of every worry: people talk about regression, starting solids, nights getting worse. What do the ranges really say?
The ranges at 4 months
| Range | At 4 months |
|---|---|
| Total sleep over 24 h | 12 to 16 hours |
| Naps per day | 3 |
| Wake window | 2 to 3 hours |
Does the "4-month regression" exist?
No published study shows a peak in night waking shared by all babies at 4 months. What happens around this age is real, but it is maturation, not a step back: sleep becomes organised in cycles closer to an adult's, with brief wakings between cycles. Some babies go through them quietly, others need help to fall back asleep. What the data really say.
Three naps, often irregular
Most babies still take three naps at this age. The last one, late in the afternoon, is often short: it mainly helps them hold on until bedtime. Short naps are common at this age: what matters is your baby's mood when they wake and through the day.
What about starting solids?
France's public health agency, Santé publique France, advises starting between 4 and 6 months, whenever suits you within that period. Before 4 months, milk only. Guidance varies from country to country, so check what applies where you live. How to go about it, allergens included.
Safe sleep
France's National Authority for Health (HAS, February 2020) recommends putting your baby to sleep:
- always on their back, on a firm mattress, in a cot with bars;
- in a suitable baby sleeping bag, with no pillow, duvet or blanket;
- with no cot bumper, positioner, soft toy or comforter in the cot;
- in a room at 18 to 20 °C, free of tobacco smoke;
- ideally in the parents' room for the first 6 months, in their own cot: no bed sharing.
When to talk to a doctor
See a doctor if your baby consistently sleeps much less than these ranges, is hard to wake or drowsy all the time, or if their sleep comes with loud snoring, pauses in breathing or a drop in their growth curve.