Association of development of chronic lung disease of newborns with neonatal colonization of Ureaplasma and cord blood interleukin‐8 level

Background: The aim of the present study was to investigate the association of chronic lung disease (CLD), neonatal Ureaplasma colonization, and interleukin‐8 (IL‐8) level of cord blood in preterm infants. Methods: In 77 infants of <32 weeks gestation, the relationship between IL‐8 level of cord blood, neonatal colonization of Ureaplasma, histological chorioamnionitis (CAM), and development of CLD was studied. Results: Five infants died and 29 infants developed CLD. The CLD group had significantly lower gestation (mean ± SD: 26.6 ± 1.8 weeks) compared with the infants without CLD (28.9 ± 1.9 weeks, P < 0.0001). Logistic analysis showed that the development of CLD was associated with gestational age (odds ratio [OR], 0.5; 95% confidence interval (CI): 0.4–0.8) and Ureaplasma colonization (OR, 4.1; 95%CI: 1.2–14.4). Ureaplasma colonization was also associated with CAM (OR, 6.5; 95%CI: 1.8–23.5), absence of respiratory distress syndrome (OR, 6.2; 95%CI: 1.3–30.5), and development of CLD (OR, 4.0; 95%CI: 1.1–15.3). Elevated cord blood IL‐8 ≥100 pg/mL was associated with female sex and the isolation of microorganisms (OR, 49.4; 95%CI: 4.6–525). Conclusion: The development of CLD defined by oxygen requirement at 36 weeks was associated with neonatal Ureaplasma colonization but not with IL‐8 level of cord blood. Elevated cord blood IL‐8 was associated with neonatal microorganisms isolation.