Definition of Bronchopulmonary Dysplasia

To the Editor.—

Once again, a study of bronchopulmonary dysplasia (BPD), this time assessing the effect of antenatal steroid therapy, has timed the criteria for diagnosis (oxygen requirement and radiographic changes) at 28 postnatal days.¹ Unfortunately, oxygen requirement, with or without radiographic changes, at this age, is being accepted widely as the clinical definition of this condition (alternatively termed chronic lung disease).^2,3 Frequently, clinical studies relate minimally, if at all, to the later outcome of infants with BPD.