Perinatal factors associated with bubbly/cystic appearance in bronchopulmonary dysplasia: a nationwide, population-based cohort study in Japan.

Background: Bronchopulmonary dysplasia (BPD) remains one of the most serious morbidities associated with preterm birth. Previous study reported that bubbly/cystic appearance on chest X-rays in the neonatal period is the strongest determinant of impaired lung function at school age in BPD patients.

Objective: To determine perinatal risk factors for bubbly/cystic appearance on chest X-rays in extremely premature infants with BPD exposed to histological chorioamnionitis histological chorioamnionitis (hCAM).

Methods: Multicenter retrospective cohort study. Methods: We analyzed 1369 extremely premature infants with severe hCAM who were admitted to the neonatal intensive care units participating in the Neonatal Research Network, Japan (NRNJ) Neonatal research network Japan. Methods: Perinatal characteristics were compared and logistic regression analysis was performed for multivariate risk factor assessment.

Results: Infants with bubbly/cystic appearance on chest X-rays underwent longer duration of invasive mechanical ventilation and required inhaled nitric oxide and home oxygen therapy more frequently. Low gestational age (odds ratio 1.244; 95% confidence interval 1.139-1.359) and preterm premature rupture of membranes (odds ratio 1.507; 95% confidence interval 1.200-1.893) were significant risk factors.

Conclusions: Low gestational age and preterm premature rupture of membranes were independent risk factors for bubbly/cystic appearance in extremely premature infants with BPD following exposure to severe hCAM.