Reduced mortality and increased BPD with histological chorioamnionitis and leukocytosis in very-low-birth-weight infants.

OBJECTIVE: To investigate the association between leukocytosis, mortality and bronchopulmonary dysplasia (BPD) in very-low-birth-weight infants (VLBW) born to mothers with histological chorioamnionitis. STUDY DESIGN: A retrospective cohort study from a single level 3 neonatal intensive care unit. The study sample included infants born to mothers with histological chorioamnionitis (n=252). Total white blood cells (WBCs) after birth were measured. Leukocytosis was defined as a total WBC count \u3e30 000 per mm(3) in the first 2 days of life. Outcomes investigated included BPD and death. Both unadjusted and multivariable analyses were carried out. RESULT: After controlling for potential confounding variables, infants who developed a leukocytosis after birth had increased odds of BPD (4.6, 95% confidence interval (95% CI): 2.0 to 10.3), but decreased odds of death (0.3, 95% CI: 0.1 to 0.90). CONCLUSION: In our population of VLBW infants born to mothers with histological chorioamnionitis, leukocytosis after birth is associated with a decrease in mortality but an increase in BPD