Infants of very low birthweight. I: Perinatal factors affecting survival.

The neonatal mortality of 692 liveborn infants with birthweights of 2000g or less born in south-east London was studied. They represented 98 per cent of all the liveborn infants of this birthweight born and admitted to hospitals in the study area. The over-all neonatal mortality rate was 303.5 per 1000 live births. The following factors were shown to have significant and independent associations with mortality: birthweight; a history of early bleeding in the mother; hour of birth; condition of the infant assessed after birth; temperature of the infant on admission to the special care unit; and the presence of respiratory disease. Implications for the organisation of neonatal care are discussed.