Association between Ureaplasma colonization and bronchopulmonary dysplasia defined by different criteria in very low birth weight infants: A retrospective cohort study

Objective: To study the association between Ureaplasma colonization and bronchopulmonary dysplasia (BPD) with different definitions in very low birth weight (VLBW) infants. Methods: A retrospective cohort study was performed with VLBW infants admitted from January 2019 to October 2021. Neonates with a positive respiratory tract Ureaplasma culture were included in the study group. Control group infants, matched for gestational age (+/- 1 week), birth weight (+/- 100 g), and birth year, had a negative respiratory tract Ureaplasma culture during the same period. The primary outcomes included the incidence and severity of BPD, defined by various criteria. Results: The study included 302 neonates (151 in the study group and 151 in the control group). After adjusting for confounders, Ureaplasma colonization was not associated with BPD as defined by the National Institutes of Health (NIH) in 2001 (adjusted odds ratio [aOR]: 0.820, 95% confidence interval [CI]: 0.362-1.860, p = .635). However, it was associated with BPD as defined by the NIH in 2018 (aOR: 2.490, 95% CI: 1.128-5.497, p = .024) and the Neonatal Research Network (NRN) in 2019 (aOR: 2.352, 95% CI: 1.077-5.134, p = .032). Additionally, VLBW infants with Ureaplasma colonization had a higher risk of moderate-severe BPD according to the NIH 2001 (aOR: 2.352, 95% CI: 1.077-5.134, p = .032), NIH 2018 (aOR: 6.339, 95% CI: 1.686-23.836, p = .006), and NRN 2019 definitions (aOR: 3.542, 95% CI: 1.267-9.904, p = .016). Conclusions: Ureaplasma colonization is not associated with BPD by the NIH 2001 definition, but is associated with an increased incidence by the NIH 2018 or NRN 2019 definitions.