LullsongSleeping through the night: what’s normal
Updated 24 October 2026 · Written by the Lullsong team. General information, not medical advice.
Short answer
Many babies don’t sleep through the night in their first year, and that is normal. In a Canadian study of 388 babies, 62% slept at least 6 hours in a row at six months and 72% at twelve months. For 8 hours, the figures were 43% and 57%. Babies who woke more did not show slower development.
What “sleeping through” means
Studies use different yardsticks: 6 hours in a row, 8 hours, or midnight to 5 am. In a New Zealand study of 75 babies whose sleep diaries were checked against video (Henderson et al., 2010), half of the babies slept from midnight to 5 am and for 8 hours by three months, and from 10 pm to 6 am by five months. At twelve months, about 72% to 85% were sleeping through, depending on the yardstick.
Read the other way, that means more than one baby in ten still woke at night at one year.
Some babies take longer
A US study followed more than 1,200 children from six months to three years (Weinraub et al., 2012). About two thirds woke rarely by six months. The other third woke most nights at six months, then less and less: about two nights a week at fifteen months and one night a week by two years.
Does it matter for development?
In the Canadian study (Pennestri et al., 2018), sleeping through the night at six or twelve months was not linked to the babies’ mental or motor development, or to their mothers’ mood. It was linked to less breastfeeding.
What helps
- Expect wide differences between babies, even between siblings.
- Keep safe sleep rules at every waking, especially when you are exhausted.
- Talk to your paediatrician about feeding, weight or breathing worries, or if your own sleep or mood is suffering.
Sources
- Pennestri MH, Laganière C, Bouvette-Turcot AA, et al. Uninterrupted infant sleep, development, and maternal mood. Pediatrics 2018;142:e20174330. https://doi.org/10.1542/peds.2017-4330
- Henderson JMT, France KG, Owens JL, Blampied NM. Sleeping through the night: the consolidation of self-regulated sleep across the first year of life. Pediatrics 2010;126:e1081-e1087. https://doi.org/10.1542/peds.2010-0976
- Weinraub M, Bender RH, Friedman SL, et al. Patterns of developmental change in infants' nighttime sleep awakenings from 6 through 36 months of age. Dev Psychol 2012;48:1511-1528. https://doi.org/10.1037/a0027680
More sleep guides
- Wake window calculator
- Nap schedule maker
- Safe sleep: the essentials
- The 4-month sleep regression: what’s actually known
- Wake windows: what the research actually says
- Is white noise safe for babies?
- When to stop swaddling
- Room temperature and what to wear
- Contact naps: what’s safe and what’s known
- Dream feeds: do they work?
- Lullabies and singing: what the research shows
Lullsong
Lullsong plays soft white noise and lullabies for naps and bedtime, with a 30-minute timer on by default.