An unborn baby needs an uninterrupted flow of oxygen to remain healthy. While in the mother's womb, the baby receives oxygen from the maternal blood supply through the placenta. Sometimes, the normal supply of blood is diminished or interrupted. If during the pregnancy or labor, the baby's blood supply is reduced or the amount of oxygen in the blood is diminished (conditions that are termed ischemia and hypoxia, respectively), the baby enters a state of "fetal distress" and is at risk for permanent brain damage and even death. Depending on the cause of the fetal distress, the mother's life may also be at risk. Because of the high risk that fetal distress presents, it is a condition that requires immediate resolution by either the alleviation of the cause or the immediate delivery of the baby.

When fetal distress is present, immediate action must be taken in order to restore proper blood supply and oxygenation to the baby. If conservative measures are unsuccessful, immediate delivery of the baby (often by cesarean section) is required in order to avoid prolonged periods of oxygen deprivation that cause permanent brain damage and may even lead to death.