ABSTRACT
Objective:To investigate the association between ureaplasma urealyticum (UU) colonization in the respiratory tract and bronchopulmonary dysplasia (BPD) in extremely preterm or extremely low birth weight infants.Methods:This was a retrospective study involving preterm infants with gestational age <28 weeks or birth weight <1 000 g who was hospitalized in the Neonatal Intensive Care Unit (NICU) of Chengdu Women's and Children's Central Hospital from June 2019 to March 2022. Respiratory tract secretion was collected for UU DNA detection within 24 h after admission. All the participants were divided into the UU-positive or negative groups based on the detection results. Clinical characteristics of the two groups were analyzed using Mann-Whitney U, t-, or Chi-square tests (Fisher exact test). Results:A total of 82 infants were enrolled, including 31 cases (37.8%) in the UU-positive group and 51 patients (62.2%) in the negative group. Among the 30 cases treated with azithromycin in the positive group, 27 (90.0%, 27/30) turned negative after two courses of treatment. The rates of premature rupture of membranes [51.6% (16/31) vs 17.6% (9/51), χ2=10.50] and prenatal antibiotic exposure [71.0% (22/31) vs 47.1% (24/51), χ2=4.47] in the UU-positive group were both higher than those in the UU-negative group (both P<0.05). Multivariate logistic regression analysis showed that premature rupture of membranes ( OR=5.893, 95% CI: 2.016-17.228) and gestational age ( OR=0.663, 95% CI: 0.441-0.999) were independent risk factors for UU colonization (both P<0.05). UU-positive group had a longer duration of oxygen use [ M ( P25- P75), 1 756 h (1 385-2 088 h) vs 1 357 h (1 128-1 656 h), Z=2.98], a longer length of hospital stay [81 d (70-105 d) vs 68 d (59-84 d), Z=3.05], and higher hospitalization costs [(201 574±70 326) yuan vs (161 288±53 412) yuan, t=－2.74] compared to the UU negative group (all P<0.05). The incidence of BPD [74.2% (23/31) vs 47.1% (24/51), χ2=5.80] and retinopathy of prematurity [93.4% (29/31) vs 74.5% (38/51), χ2=4.68] in the UU positive group was higher than those in the UU-negative group (both P<0.05). No significant correlation was found between UU colonization and the severity of BPD ( P>0.05). Conclusion:UU colonization may increase the incidence of BPD, but there was no clear correlation with the severity of BPD.