Future cohort-BIHIVE2: To develop these markers further to the point where we have validated a marker with >90% sensitivity and specificity for moderate/severe HIE we will need to recruit a further cohort of carefully recruited infants with high quality biobanking at birth and detailed clinical phenotyping. This is the main work of this current application. We will require a further cohort of 300 infants with perinatal asphyxia, of whom 60 will develop HIE and 30 will develop moderate to severe HIE. We will also need to recruit 300 contemporary control infants. To recruit this number of infants with perinatal asphyxia we will need to study 30,000 live births. We have therefore expanded our study centres to include Karolinska University Hospital, Stockholm, a large state of the art maternity hospital with 10,000 live births per annum.