[Fetal shock syndrome]

Fetal hypoxia before and during delivery occurs if a critical limit of uterine and umbilical blood flow is achieved or subsided below that border. As a result of the increased catecholamine secretion a redistribution of blood flow to the different organs of the fetus takes place. The brain, lungs and adrenals are the preferentially perfused organs, whereas the tissues of the kidneys, the skin and other areas have a reduced blood supply. There is, however, no unlimited protective mechanism of the relatively well perfused organs during fetal shock. Brain injuries are dependent on glucose concentration and the arterial blood pressure. The irreversibility of fetal shock is introduced by the development of coagulation disorders and fibrin deposits in the fetal organs, the fall of blood pressure, fetal acidosis and an increased permeability of the blood vessels. Before this state is reached, cardiovascular alterations, changes in acid base status and the continuously measured PO2 take place. These signs should be used to prevent fetal injuries by application of the right measures at the right time.