Association of Early Postnatal Neutropenia and Development of Bronchopulmonary Dysplasia in Preterm Infants

ABSTRACT

PURPOSE: To see if a similar relationship exists between the decreased number of circulating neutrophils and the development of bronchopulmonary dysplasia (BPD) in preterm infants, we tried to test the hypothesis that claims that preterm infants, who develop BPD, have decreased number of circulating neutrophils than those who do not develop BPD. METHODS: A retrospective cohort study was conducted in 167 preterm infants from August 1995 to July 1997, who were admitted in the neonatal intensive care unit (NICU) of Seoul National University Children's Hospital. RESULTS: BPD was diagnosed in 16% (27/167) of preterm infants. We compared the clinical characteristics of the study population according to the presence or absence of BPD. Compared to non-BPD group, the BPD group had a lower gestational age (29.4 +/- 2.7weeks versus 32.7 +/- 1.7 weeks), lower birth weight (1,240 +/- 486g versus 1,780 +/- 420g), lower incidence of prenatal steroid use (2/27 versus 41/140), decreased number of circulating neutrophils (3,622 +/- 4,866/microliter versus 7,586 +/- 4,545/microliter) at 1 day of life. After adjusting for the variables of the above risk factors, neutropenia (<2,500/microliter) in the peripheral blood increased the odds ratio of developing BPD (OR 46.3, 95% CI 17.3-117.2). CONCLUSION: Early postnatal neutropenia might be an important risk factor for the development of BPD and lung injury responsible for the development of BPD might begin at the early postnatal period.