Editor,—Professor Pharoah questions whether the increased rate of cerebral palsy among newborn infants who were randomly allocated early postnatal dexamethasone therapy in the trial by Shinwell et al 1 might be because dexamethasone increased survival of infants who were impaired before birth, and not because dexamethasone caused cerebral impairment.

However, two recent systematic reviews of randomised trials of postnatal dexamethasone therapy in infants at risk of chronic lung disease do not support this hypothesis. Halliday and Ehrenkrantz found no difference in survival in trials of dexamethasone given within 96 hours of birth.2 Doyle and Davis found no difference in survival, overall or in any subgroups, in trials of dexamethasone therapy at any time after birth.3 Both reviews concluded that postnatal dexamethasone may cause neurological dysfunction and called for further trials with appropriate follow up.

Professor Doyle is currently co-ordinating such a trial in infants under 1000 g or less than 29 weeks who are ventilated after 7 days from birth (the DART study, Dexamethasone in tiny infants—a Randomised Trial). Those interested in participating in this important study are very welcome to contact him at l.doyle{at}obgyn-rwh.unimelb.edu.au.