A 15-year survey of chronic lung disease of prematurity.

The in-hospital findings for infants of 500-1,500 g birthweight admitted for intensive care over the years 1971-87 were reviewed at four intervals. Survival rate improved substantially. The incidence of chronic lung disease (CLD) in survivors at 28 days of age was unchanged though severity diminished in terms of both mortality and degree of radiographic change. Mean conceptual age for ceasing supplemental oxygen was 32 weeks for those with normal X-rays and 37 weeks for abnormal X-rays regardless of initial degree of immaturity. CLD was diagnosed twice as often when supplemental oxygen beyond 28 days was used as an indicator as against an abnormal X-ray and was hence unreliable for this purpose. Since candidates for CLD are a heterogeneous group care is needed in analysis or selection of material in forming conclusions which concern etiology or management.