Maternal smoking in pregnancy increases the duration of home oxygen therapy in infants with bronchopulmonary dysplasia

Abstract

Bronchopulmonary dysplasia (BPD) secondary to prematurity is treated with home oxygen therapy (HOT) after discharge from hospital. HOT supports infants, but is burdensome. Antenatal maternal smoking is a risk factor for BPD, but its impact upon duration of HOT in BPD is unknown. We aimed to understand the impact of prenatal maternal smoking upon the duration of HOT for infants with BPD in our clinic. Methods: Our clinic routinely collects data on maternal smoking, home oxygen prescription, and results of sleep studies in BPD for service planning. We do overnight saturation monitoring at approximately 4 weekly intervals guided by the clinical state to efficiently wean oxygen. We reviewed all cases for which we a smoking history for a 10 year period. We compared the time to cessation of HOT in a survival analysis with a log-rank test. Results: We have been referred 231 infants of which 197 have weaned off oxygen. Maternal smoking history was available for 157 cases. HOT duration was longer in the smoking group (p = 0.03, see fig. 1). This effect was most marked for those in oxygen the longest – at the 75th centile of oxygen duration, smoking was associated with an additional 20 days in oxygen. Conclusions: Antenatal smoking is associated with increased duration of home oxygen for infants with BPD. Future work will explore postnatal exposure to cigarette smoke and duration of oxygen therapy.