Neuropathologic features of idiopathic respiratory distress syndrome.

Evaluation of the neuropathologic alterations occurring in 170 consecutive autopsies in premature infants dying of the idiopathic respiratory distress syndrome (IRDS) reveals two large groups, hemorrhagic and nonhemorrhagic. Hemorrhages occurred in all possible sites and formed the single largest group. Such hemorrhages appeared to be related to the early death of many premature infants. The nonhemorrhagic group was quite variable, with the largest category of associated lesions being periventricular leukomalacia, the frequency of which increased with increasing age. We suggest that the nonhemorrhagic group may be an important factor in the morbidity of survivors.