Post-natal Corticosteroids Are Associated with Reduced Expiratory Flows in Children Born Very Preterm

Aim: Infants born very prematurely often received corticosteroids to minimise the risk of developing bronchopulmonary dysplasia (BPD) but their long term impact on lung function at school age is unclear.

Methods: A cross-sectional study of 105 children [mean gestation of 27 weeks] was undertaken. Lung function assessments were conducted at a mean age of 10 years according to standard criteria. Corticosteroid dose was obtained from the medical record.

Results: Spirometry in the BPD group was not significantly different to the non-BPD group, mean per-cent predicted (95% confidence interval) forced expiratory volume in 1 s (FEV1) 83% (79, 87) versus 86% (83, 90), FEF25%-75% 67% (60, 73) versus 75% (69, 81). Antenatal steroid treatment alone did not adversely affect airflow FEV1, 88% (84.92) versus 90% (82.97), and forced expiratory flow (FEF)25%-75%, 75% (69.81) versus 87% (70.104). Children who received post-natal corticosteroids had significantly lower flows than those who did not (FEV1 82% (78.85) vs. 88% (85.92), P = 0.006; FEF25%-75% 65% (59.71) vs. 78% (72.84), P = 0.003). Regression analysis revealed days on oxygen and days ventilated were statistically significant but weak predictors of airflow at 10 years of age.

Conclusions: A diagnosis of BPD did not predict reduced spirometry in middle childhood. Children who received post-natal corticosteroids as preterm infants had reduced expiratory flows compared with those who did not. While post-natal corticosteroids may be a marker of severity of lung disease, the potential of post-natal corticosteroids to influence lung development requires further investigation.