The blood of a term baby, like that of a child or adult, should be 95 to 100% saturated with oxygen. The blood of a premature baby receiving extra oxygen is usually maintained between about 88 and 95% saturation, not higher, to prevent retinopathy of prematurity, a serious eye condition.
In the hospital, pulse oximetry is used to measure the amount of oxygen in the blood. When the blood does not have enough oxygen, it is called a desaturation. Desaturations can cause a bluish tint to the lips or skin and cause a baby to lose tone or become “floppy.”