Neonatal chronic lung disease, oxygen dependency and a family history of asthma.

We examined the relationship between a family history of asthma (FHA), neonatal chronic lung disease (CLD), and oxygen dependency in an inception cohort study of all 24- to 30-week gestation infants admitted to the sole tertiary perinatal center in Western Australia. One hundred and forty-four infants were admitted during the study period; 116 had data analyzed, 112 of whom survived to discharge. Respiratory morbidity was common and the prevalence increased with decreasing gestation. Hyaline membrane disease (HMD) occurred in 92 (79%) and CLD (oxygen dependency at 28 days) in 62 (53%); 35 (30%) were oxygen dependent at 36 weeks corrected age, and 16 (14%) were oxygen dependent at term. Thirty-two infants had an FHA which was equally distributed between those infants with and without CLD. Infants with an FHA were more likely to be oxygen dependent at term (relative risk 4.4; 95% CI 1.7,11.1). Thirty-eight percent of mothers smoked; 68% of their infants developed HMD compared to 89% of those whose mothers did not smoke. Logistic regression identified GA