The role of blood gas and acid-base assessment in the diagnosis of intrapartum fetal asphyxia.

The diagnosis of fetal asphyxia requires a blood gas and acid-base assessment demonstrating a significant metabolic acidosis. However, the fetus may tolerate an asphyxial insult without central nervous system injury because of the fetal cardiovascular adaptation to hypoxemia. Prediction of the significance of an asphyxial insult to the fetus requires a measure of both the duration and degree of the asphyxia as well as an expression of the fetal compensatory response to the asphyxia.