[Chronic lung disease in a cohort of children born before the 28th gestational week. Incidence and etiological factors].

Introduction: Advances in perinatal care have increased the survival rate of extremely preterm (ETP) infants during the last decades. A key factor has been the ability to provide respiratory support with mechanical ventilation. Mechanical ventilation, however, is associated with pulmonary disease, such as bronchopulmonary dysplasia (BPD).