Azithromycin for Preventing Bronchopulmonary Dysplasia in Extremely Preterm Infants: A Cohort Study

To test the effect of azithromycin in reducing bronchopulmonary dysplasia (BPD) risk in extremely preterm infants (EPI) without pulmonary infection.

A retrospective cohort study was performed in EPI in a tertiary unit from September 2018 to September 2022. Since only Ureaplasma species positive infants were treated with azithromycin, we included infants without Ureaplasma species (no azithromycin treatment) and those diagnosed with Ureaplasma species colonization (azithromycin treatment) in the study, while infants with Ureaplasma species pneumonia were excluded. The primary outcome was grade II⁺ BPD, defined as BPD of grade II or higher according to the updated NICHD criteria (2018). Multiple logistic regression analysis was used to identify the independent association between grade II⁺ BPD and azithromycin treatment.

A total of 237 EPIs were included in the current study, of which 202 infants were classified as no azithromycin treatment (Ureaplasma species negative) and 35 infants were classified as azithromycin treatment (Ureaplasma species colonization). Clinical characteristics were similar between groups. Infants treated with azithromycin had a significantly lower rate of grade II⁺ BPD (8.6% vs. 31.2%, p = 0.006), and shorter duration of invasive ventilation (0 vs. 3 days, p = 0.045) compared to untreated ones. After adjusting for confounders, azithromycin treatment was significantly associated with reduced risk of grade II⁺ BPD in the whole cohort (odd ratio [OR] 0.211, 95% CI: 0.056, 0.786, p = 0.020], and infants absent of other pulmonary infection (OR 0.115, 95% CI: 0.014, 0.979, p = 0.048).

Azithromycin is associated with a reduced risk of grade II⁺ BPD in EPIs, likely due to its anti-inflammatory effect.