Babies don’t generally fall immediately into a deep sleep. Generally, a baby will nod slowly off to dreamland, spending several minutes in an active sleep cycle. During this time she will dream, just like her parents do. You will see her make faces, and she may make noises such as gurgling or even light crying. In addition to baby’s need to go through a light sleep before falling into a deep, comfortable sleep, baby will come out of deep sleep into an active sleep cycle every fifty minutes or so. These cycles typically last only a few minutes if she doesn’t wake up.
During active sleep phases, babies wake up easily. However, if your baby is comfortable, you can often help her fall back into deep sleep. The reason babies’ sleep cycles change so rapidly is that babies can’t take care of their own needs as readily as an adult can. Your baby’s only way of communicating a need is to cry, and if she were to sleep too deeply for too long, she wouldn’t be able to let you know she is hungry, cold, or otherwise uncomfortable.
Of course, when your baby has a need, you want her to wake up, because you want to take care of her. Whether it’s feeding, an extra blanket, a diaper change, or something else, you want to make sure your baby’s needs are met. However, there are many times when babies wake up when it would be better for them to sleep.
If baby is going through an active sleep cycle, she may make faces, noises, or move around. Try singing or speaking soothingly to her, or gently rubbing her back. Try to keep the room quiet and avoid noises that could startle baby awake. Different babies respond to different things, so feel free to experiment a bit. Ultimately, you know your baby best. Some babies are able to drift into deep sleep easier with white noise, such as a fan in the room or a vaporizer.
You can tell when your baby falls into deep sleep because her body will go limp, with her muscles losing tension. She will stop making facial expressions and relax, her breathing becoming slow and rhythmic. Most babies in deep sleep can sleep through normal household noises such as conversation without waking.