Perinatal risk factors for bronchopulmonary dysplasia in extremely low gestational age infants: a pregnancy disorder-based approach.

ABSTRACT

OBJECTIVE: To analyze risk factors for bronchopulmonary dysplasia (BPD) or death according to the condition leading to extremely preterm birth, preterm labor, or vascular disorders. STUDY DESIGN: Retrospective study of all premature births before 28 weeks of gestation in a single Level III institution. Mother/infants were attributed to the "preterm labor" or "vascular disorder" group according to the condition leading to delivery. Characteristics and outcomes were compared between groups. Independent risk factors for BPD or the composite outcome "BPD or death" were identified within each group. RESULTS: Three hundred ninety-six infants from 349 pregnancies were characterized for perinatal characteristics. BPD was significantly more frequent in the vascular disease group than in the preterm labor group (29% vs 11%, P < .01). Independent risk factors of BPD were a low gestational age in the preterm labor group and severe growth restriction in the vascular disease group. CONCLUSION: Classification of preterm birth according to the condition leading to delivery might help to reduce confounding of risk factors for BPD. Intrauterine vascular disorders are significantly associated with BPD.