Is your baby sleeping enough for their age?

From an expert panel, rather than from a survey of how babies actually sleep. The National Sleep Foundation brought sleep specialists and paediatric bodies together in 2015 to agree a recommended band and a wider may-be-appropriate band for each age, and the AASM published its own consensus in 2016. Galland et al. (2012) is the descriptive half of the picture, pooling studies of what babies do rather than what they should do.

The largest randomised controlled trial we have says no. Hiscock et al. (2008) followed 328 children to age 6 and found no difference between the sleep-trained and the rest on emotional health, behaviour, sleep quality, the child-parent relationship or cortisol. That covers the specific harms people worry about out loud. Whether you sleep train is a decision about your family, and the trial gives you no medical reason to feel pushed either way.

14 to 17 hours across the whole 24 for a newborn aged 0 to 3 months, with 11 to 13 at the bottom and 18 to 19 at the top still counted as possibly appropriate. Those hours arrive in short bouts because the circadian rhythm has not started up yet and a newborn stomach needs feeding often. Stretches of only 2 to 4 hours are completely normal in the first 8 weeks (Hirshkowitz et al., 2015).

Because the spread at any given age is enormous. Galland et al. (2012) pooled the descriptive studies and found wide individual variation, with temperament and feeding method both feeding into how quickly night sleep consolidates. At 12 months, 15 to 25% of babies are still waking at least once, so the friend whose baby sleeps through is describing one draw from a wide distribution and not a standard you have missed.

A baby at the top of the range is usually fine, as long as they feed well, gain weight and are alert when they are awake. What does warrant a call to your doctor is a baby who is consistently hard to rouse for feeds, who seems drowsy or floppy while awake, or who goes well past the upper threshold of 19 or more hours as a newborn. Jaundice, infection and metabolic problems can all show up first as a newborn who sleeps too easily.

Newborns take 4 to 6 irregular naps, most babies are down to 3 by 4 to 6 months, the third one goes between 6 and 9 months, and one nap is the usual pattern by 12 to 18 months. Napping stops altogether somewhere between 2 and 5 years, with a lot of variation. Each of those drops tends to bring a fortnight of overtiredness and extra night waking while the day resettles, and once a toddler is down to one nap the screen time guidelines start to matter for how the rest of the day is shaped.

Around 4 months a baby swaps the two-stage newborn sleep pattern for the four-stage adult one, light stages 1 and 2 included, and the changeover brings 2 to 6 weeks of frequent night waking, short naps and trouble settling. Later regressions pass and leave things as they were. This one does not, because the sleep it disrupts has been permanently rebuilt, so the newborn baseline you are hoping to get back to no longer exists.

No, it does not cost your baby sleep. Back sleeping on a firm flat surface with no soft bedding or loose objects, which is what the AAP and NHS both recommend, leaves total sleep duration unchanged. A baby who has been put down on their front by a hospital or another carer may settle less easily on their back for a few days before adapting. Back sleeping cuts the risk of sudden unexpected infant death (SUID) by roughly 50%, which is the largest single effect in any of this guidance.