Oxygen delivery to the brain before and after birth

We studied the relationship between cerebral oxygen consumption and cerebral oxygen delivery (cerebral blood flow x arterial oxygen content) in fetal, newborn, and adult sheep, Relative to the amount of oxygen consumed, cerebral oxygen delivery in the fetus exceeds that in the lamb and adult by 70 percent. This may represent a protective advantage for the fetus or simply a necessary adaptation to the low arterial oxygen pressure in the intrauterine environment.