Abstract 1498 Poster Session III, Monday, 5/3 (poster 26)

Objective: To determine the frequency of BPD and postneonatal chronic lung disease (PCLD) in infants at 12 and 36 months adjusted age(aa) over a 20 year period, and to examine the severity of PCLD as reflected by the duration of post-discharge chronic oxygen dependence.

Methods: All infants weighing 1250 g or less, born in Southern Alberta between 1977 and 1996, were prospectively enrolled in a long term Perinatal Follow-up Program. BPD was determined at discharge using Northway's criteria, and PCLD was determined at 12 and 36 months aa. PCLD was defined as presence of any of: chronic post discharge oxygen dependence, repeated hospitalization due to respiratory illnesses, recurrent lower respiratory illnesses and chronic utilization of respiratory medications. BPD and PCLD rates were calculated using total survivors as the denominator.

Results: (Table) The frequency of BPD has not changed significantly. PCLD is slightly more common at 12 mo aa during the most recent time periods, although it has usually resolved by 36 mo aa. The rate of oxygen dependence among infants weighing 1250 g or less at birth in this region remains near 30% but the duration of home oxygen therapy has decreased from a peak of 400 days in 1981-84 to approximately 150 days in 1993-96, suggesting a possible decrease in the severity of PCLD.

Table 1 No caption available
Full size table

Conclusions: Despite multiple changes in antenatal and neonatal interventions and improved survival rates, the rate of BPD in infants weighing 1250 g or less, has not decreased. There has been a slight increase in the frequency of PCLD at 12 mo aa but this increase did not persist to 36 mo. The frequency of chronic post-discharge oxygen dependence remains relatively high in this geographic area, but the duration has markedly decreased, indicating either a change in care or decreased severity of PCLD.