Why does baby wake up at night?
Dr. Valleteau de Moulliac,
Consulting pediatrician for Laboratoires Sarbec
A newborn goes through different types of sleep: drowsiness (the state between being awake and asleep), quiet sleep, and active sleep (in this case, the face is expressive, and the eyes move under the eyelids). Generally, during a sleep period lasting 3 to 4 hours, the phases of active sleep and deep sleep alternate 2 to 3 times in a well-fed baby. If the baby is in active sleep, they may grimace, smile, and sometimes cry. This is normal, there is no need to wake them! However, if the baby is truly awake and hungry, they will move their whole body and have their eyes wide open.
The day-night rhythm normally and naturally settles in before the age of 6 months, often around 4 months, with great variability from one child to another, since some infants can acquire it as early as the 3rd or 4th week. So, up to 4 months (sometimes 6), it is normal for a baby to wake up at night to satisfy their hunger.
After 6 months, most infants sleep 8 to 12 hours per night with 3 naps. The nap before dinner disappears around 9 months. Sleep is no longer regulated by purely instinctive causes (hunger, satiety: so be careful with the milk bottle or breastfeeding for convenience) but by the gradual discovery of the outside world and especially of the mother, who at 9 months is perceived as a separate person on whom the child depends and whose separation is a source of insecurity and anxiety. From this point on, all environmental factors become increasingly important. This period is marked by difficulties falling asleep, leading to bedtime rituals that you need to know and respect.
All these environmental factors can therefore disrupt their nighttime sleep: illnesses, educational mistakes, relationship issues, family or work tensions, crowding/noise, excessive or too low temperature, but all that is… another story!!!
But simply remember that your baby who “wakes up” at night may be between two sleep phases and is trying to fall back asleep. Let them cry for a few minutes (there is no risk in this) to see if they fall back asleep on their own. If not, reassure them by talking to them or gently stroking them. But above all, avoid feeding them or taking them out of bed. Otherwise, you risk really waking them up… and getting them back to sleep will be hard, especially if it becomes a habit!
