Intrauterine hypoxia (IH, and birth asphyxia) occur when the fetus is deprived of an adequate supply of oxygen. IH is used to describe inadequate oxygen availability during the gestation period, birth asphyxia (also referred to as perinatal asphyxia or Asphyxia neonatorum ) can result from inadequate supply of oxygen immediately prior to, during or just after delivery. There is considerable controversy over the diagnosis of birth asphyxia due to medicolegal reasons. Because of its lack of precision, the term is eschewed in modern obstetrics.
IH may be due to a variety of reasons such as cord prolapse, cord occlusion, placental infarction and maternal smoking. Intrauterine growth restriction (IUGR) may cause or be the result of hypoxia. Birth asphyxia may result due to prolonged labor, breech delivery in full-term infants; placental abruption, and maternal sedation in premature infants. Oxygen deprivation is the most common cause of perinatal brain injury.
Intrauterine hypoxia and birth asphyxia can cause hypoxic ischemic encephalopathy which is cellular damage that occurs within the central nervous system (the brain and spinal cord) from inadequate oxygen. This results in an increased mortality rate, including an increased risk of Sudden infant death syndrome (SIDS). Oxygen deprivation in the fetus and neonate have been implicated as either a primary or as a contributing risk factor in numerous neurological and neuropsychiatric disorders such as epilepsy, ADHD, eating disorders and cerebral palsy. " The problem of perinatal brain injury, in terms of the costs to society and to the affected individuals and their families, is extraordinary." (Yafeng Dong, PhD)