ABSTRACT
<p><b>OBJECTIVE</b>To study the relationship between Ureaplasma urealyticum (UU) infection in the lower respiratory tract and the incidence of bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW) infants with respiratory distress syndrome (RDS).</p><p><b>METHODS</b>Seventy-three VLBW infants diagnosed with neonatal RDS, who had received at least one dose of pulmonary surfactant, as well as mechanical ventilation, and were hospitalized for over 28 days, were recruited. Endotracheal aspirates were obtained from the lower respiratory tract and examined by real-time PCR to detect UU DNA. The infants were divided into UU infection and non-UU infection groups according to examination results. Clinical characteristics and the incidence of BPD were compared between the two groups.</p><p><b>RESULTS</b>Compared with the non-UU infection group, the UU infection group had a higher rate of maternal vaginal delivery, higher incidence of recurrent nosocomial pulmonary infection and premature rupture of membranes (PROM), and longer durations of PROM, oxygen supplementation, and hospital stay; in addition, the UU infection group had higher plasma IgM level, leukocyte count, and neutrophil count within 3 hours after birth. Among 73 VLBW infants, 45 developed BPD; the incidence of BPD in the UU infection group was 90% (19/21), versus 50% (26/52) in the non-UU infection group (P<0.01).</p><p><b>CONCLUSIONS</b>UU infection in the lower respiratory tract increases the incidence of BPD in VLBW infants with RDS.</p>