Antecedents of clinically significant pulmonary hemorrhage among newborn infants

OBJECTIVE: To evaluate risk factor profiles associated with clinically significant pulmonary hemorrhage (PH) in preterm (PT) and term infants. STUDY DESIGN: Case-control study of all infants with PH cared for in three Harvard-affiliated neonatal intensive care units between 1987 and 1994. RESULTS: A total of 50 cases of PH occurred in PT infants (gestational age (GA) of ≤34 weeks), and 26 cases occurred in near-term/full-term (NT/FT) infants (GA of >34 weeks). The median age at the time of PH was 46 hours among PT infants compared with 6 hours among NT/FT infants. For PT infants, four factors best predicted PH: a GA of between 24 and 26 weeks and antenatal glucocorticoid treatment reduced the risk (odds ratios (ORs) of 0.7 and 0.3, respectively), whereas requirement for resuscitation with positive pressure ventilation and thrombocytopenia were associated with increased risk (ORs of 4.3 and 4.0, respectively). Among the NT/FT infants, the model included three variables: meconium aspiration (OR 4.9), requirement for resuscitation with positive pressure ventilation (OR 2.9), and hypotension (OR 3.5). CONCLUSION: Antecedent factors and timing of PH differ between PT and NT/FT infants, suggesting that the mechanisms contributing to PH are influenced by developmental maturity as well as perinatal and neonatal medical conditions and interventions.