Newborns and day-night confusion

Many parents find that their newborn sleeps peacefully through the afternoon and then is wide awake at two in the morning. This is very common, and it is not something you have caused. A new baby simply has no sense yet of which hours are day and which are night.

Why it happens

Adults have an internal body clock that makes us sleepy in the evening and alert in the morning. It works partly through hormones, such as melatonin at night and cortisol in the morning, that rise and fall on a roughly 24-hour cycle.

A newborn's body clock is not running yet. For about the first two months, babies sleep and wake around the clock, with no link to the time of day. They also wake every few hours to feed, whatever the hour.

When it usually settles

The body clock starts working in the second or third month. In a study that followed healthy full-term babies at home, the daily rhythm of cortisol appeared at around 8 weeks and of melatonin about a week later, and this was also when longer night-time sleep began.

So for most babies, the days and nights start to sort themselves out at around 8–9 weeks. Some get there sooner and some later. A range is a better guide than a deadline, so do not worry if your baby takes a little longer.

What helps

You cannot rush a body clock, but you can give it clear signals.

During the day

• Open the curtains and let in plenty of daylight. Babies who get more light in the early afternoon have been found to sleep better at night.
• Talk, sing and play while your baby is awake.
• Let daytime naps happen in normal household noise and light, in a safe sleep space. There is no need to tiptoe around.

At night

• Keep the room dark. Use only a dim light for feeds and nappy changes.
• Keep night-time contact to what is needed: feeding, burping, changing and gentle settling.
• Speak softly, and save play and chat for the daytime.
• Put your baby back down once they are fed and changed.

Night waking and feeding is normal

In the first weeks, babies wake at night because they need to eat. Breastfed newborns usually feed about every 2 hours, around 10–12 times in 24 hours. Formula-fed newborns usually feed every 2–3 hours, and at least 8 times in 24 hours. Your midwife, health visitor or doctor may give you advice that suits your own baby.

In total, newborns sleep about 14–17 hours in 24 hours, and some sleep even more. That sleep comes in short pieces spread across the day and night. Sleeping straight through the night is not expected at this age. Some babies manage a stretch of 5–6 hours by 2–3 months, and many do not.

When to talk to a doctor

Talk to your doctor or health visitor soon if your child:

• snores often, seems to struggle to breathe at night, or is very sleepy during the day;
• is not gaining weight as expected, or has lost their appetite;
• has sleep problems you are finding hard to manage.

If you are worried and not sure what to do, it is always fine to ask.

If your baby is under 3 months old with a temperature of 38 °C (100.4 °F) or higher, or 3–6 months old with 39 °C (102.2 °F) or higher, call your doctor straight away. If you cannot reach a doctor, call your local emergency number.

Call your local emergency number now if your baby:

• stops breathing for more than 20 seconds;
• is breathing very fast or with great effort — grunting, or sucking their tummy in with each breath;
• has blue, grey, pale or blotchy skin, lips or tongue;
• is very hard to wake, or will not wake up;
• is floppy, or is not feeding;
• has a seizure (fit), or a rash that does not fade when you press a glass against it.

Sources

• Joseph D. et al. (2015), Getting rhythm: how do babies do it?, Archives of Disease in Childhood – Fetal and Neonatal Edition — PubMed 25245173
• Harrison Y. (2004), The relationship between daytime exposure to light and night-time sleep in 6–12-week-old infants, Journal of Sleep Research — PubMed 15560769
• American Academy of Pediatrics, HealthyChildren.org — Reversing day-night reversal
• American Academy of Pediatrics, HealthyChildren.org — How often and how much should your baby eat?
• American Academy of Pediatrics, HealthyChildren.org — Sleep apnea: signs to watch for
• American Academy of Pediatrics, HealthyChildren.org — When to call the pediatrician: fever
• NHS — Helping your baby to sleep
• NHS — Is your baby or toddler seriously ill?
• KidsHealth (Nemours) — Sleep and your newborn
• KidsHealth (Nemours) — Failure to thrive: when to see a doctor
• Sleep Foundation (medically reviewed) — Newborn sleep