The downside is that because they are always in lighter stages of sleep, they do not generally stay asleep for very long stretches. (dreamteambaby.com)
«We know that the breastsleeping mother / baby pair both sleep in lighter stages, which makes them more sensitive to the behavior of the other. (fitpregnancy.com)
To start, as the night wears on, your body naturally moves into lighter stages of slumber, during which it's easier to be roused. (sleep.org)