Baby sleep at 3 months
day and night start to differ
At 3 months, day and night start to differ. Nights often get longer, while naps stay frequent and irregular. Here are the ranges for this age, and what they mean.
The ranges at 3 months
| Range | At 3 months |
|---|---|
| Total sleep over 24 h | 14 to 17 hours |
| Naps per day | 3 or 4 |
| Wake window | 1 h 15 min to 2 h 30 min |
What changes around 3 months
Before 3 months, a newborn lives in short cycles driven by hunger, regardless of day or night. Their own melatonin production starts at around 8 to 12 weeks: this is what gradually gathers sleep into the night.
Sleeping 5 to 6 hours in a row, what studies call "sleeping through the night", becomes possible around 3 to 4 months. Possible does not mean achieved: many babies still wake up, and that is normal.
Good news for your evenings: crying increases from the second week, peaks between the fifth and eighth, then decreases (Barr, 1990).
Helping the rhythm settle
- Daylight during the day, especially in the morning, and dim light in the evening.
- A short routine before the night: the same steps, in the same order. Why it matters.
- Put your baby down at the first signs of tiredness: yawning, a faraway look, rubbing the eyes. An overtired baby often finds it harder to fall asleep.
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.