Changes in the Circulation at Birth

Changes in the Circulation at BirthIN the recent National Survey of Perinatal M~rtality,'~ in England, Scotland and Wales the 'respiratory distress syndrome' was the commonest cause of death in newborn infants during the first week.Hyaline membrane or massive pulmonary haemorrhage was present in 22 per cent of infants (197 of 901).'Hyaline membrane disease' is responsible for about a third of the neonatal deaths in the United States'.The numerous hypotheses suggested to account for this disease include increased surface tension of the alveoli3, decreased pulmonary fibrinolytic activity'', vasomotor hypotonia 14, % 16, and injury to pulmonary capillaries5> *.The