[Neonatal colonization by Ureaplasma urealyticum and the development of bronchopulmonary dysplasia]

The study purpose was to investigate the association between neonatal Ureaplasma urealyticum isolation, and bronchopulmonary dysplasia (BDP), in infants who had birth weights < 1,500 g, admitted in the Pediatric Intensive Care Unit, La Fe Hospital, Valencia, Spain.

A cohort study was designed, since March 1996 until April 1998, with a cohort of exposed and no exposed, determined by isolation of U. urealyticum in tracheal aspirate or pharyngeal cultures. 137 infants were admitted to the intensive care unit in this period, and 101 of them were enrolled in this study.

U. urealyticum was isolated in 27 (26.7%) patients. The infants with U. urealyticum positive culture had a significantly lower gestational age (mean 28.1, SD 2.4 vs 29.2, SD 2.4; p = 0.048) than negative culture infants. BDP occurred in 30 infants (29.7%), and was significantly associated with decreasing gestational age (mean 26.9, SD 1.7 vs 29.7, SD 2.2; p < 0.001) and lower birth weight (mean 965.8, SD 166.7 vs 1121.4, SD 232.1; p < 0.001). However, after correction for gestational age by logistic regression analysis, DBP was significantly related to decreasing gestational age, but not to the presence of a positive U. urealyticum culture. In the cohort of U. urealyticum positive infants, BPD occurred in 9 (33%) vs 21 (28%) in the not colonized cohort. The odds ratio associated with colonization was 1.3 (CI 95% 0.5-3.2; p = 0.63).

BPD was significantly associated with decreasing gestational age, independently of birth weight and U. urealyticum colonization.