Damage to the human brain that occurs around the time of birth is attributable to a variety of proximal causes. These include hemorrhage, infection, metabolic difficulties and hypoxia/anoxia. Of these, hypoxia and related conditions constitute the majority of perinatal injuries. Hypoxia can result from conditions related to the mother or the fetus. For example, hypoxia can result from a decreased concentration of oxygen in the air breathed by the mother as might occur at high altitude. It can also result from a decreased blood flow due to rupture or obstruction (referred to as ischemia) of blood vessels of the mother or fetus. Further, it can be the result of reduced cardiac (abnormal valve functioning of the heart) or pulmonary functioning (e.g., pulmonary disease of the mother; hyaline membrane disease of the infant).
In the perinatal period the predominant cause is ‘birth asphyxia’ which is technically referred to as critically impaired intrapartum gas exchange. This may result from many factors such as umbilical cord prolapse, abruption placentae or immaturity of the lungs. In the prenatal period the most commonly encountered problem of oxygen exchange is prolonged hypoxia due to placental inadequacies; this form of hypoxia often results in babies who are abnormally small for gestational age.
Several terms are used to denote a condition in which the mother or the fetus experience inadequate oxygen. Hypoxia is the term used to indicate a deficiency of oxygen. A related term that is often used in relation to perinatal brain injury is anoxia, meaning without oxygen. Asphyxia refers to the physiological results of hypoxia or anoxia.
KeywordsPreterm Infant Severe Hypoxia Bronchopulmonary Dysplasia Perinatal Asphyxia Birth Asphyxia
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