Circadian rhythm disorder in newborns

Circadian rhythm disorder in newborns ("Swapped day and night")

One of the most common complaints of young parents is that their newborn sleeps wonderfully during the day, but throws a "party" of fussing and crying at night. This condition, known as day‑night confusion, is a classic manifestation of immature circadian rhythms—our internal biological clock. It is not "bad behavior" nor an illness, but a completely normal and expected stage of the child’s adaptation to life outside the womb.

What are circadian rhythms and why are they absent at birth?

Circadian rhythms are 24‑hour cycles that regulate sleep and wakefulness. The main sleep hormone is melatonin, whose production is triggered by darkness. In the womb the baby received melatonin from the mother. After birth, its own production mechanism is not yet established. The internal clock "doesn’t know" when it is day or night. This mechanism matures gradually up to 2–4 months. More details are discussed in the article about newborn sleep physiology.

How to help the child set the clock?

Parents can help the child synchronize its rhythms more quickly:

• Daylight: Provide bright, natural lighting. Do not cover windows during daytime sleep.
• Darkness at night: Maintain maximum darkness. For nighttime care use a dim night‑light.
• Social cues: Interact actively with the baby during the day, and keep all nighttime interactions as calm and quiet as possible.

Read about other sleep problems on our website.