Perinatal corticosteroids and the developing lung.

A significant number of infants are born prematurely each year, many of whom will develop respiratory disease and require ventilation. A substantial number of these infants will die and many of the survivors will subsequently develop chronic inflammatory lung disease. Administration of corticosteroids to women prior to a premature delivery is associated with a significant reduction in mortality and in the incidence of respiratory distress syndrome and intracranial haemorrhage in their infants once born. Postnatal administration of corticosteroids to the infant who develops chronic lung disease has been widely practised for many years. Recent meta-analyses have suggested that benefit may be limited. Treatment is also associated with a range of different side-effects but it has been assumed that the cost-benefit ratio favoured treatment. Recent evidence of permanent and highly significant long-term adverse effects has questioned the validity of this judgement.