Authors' objectives: Systematic reviews have reported conflicting evidence to confirm if macrolides reduce rates of chronic lung disease of prematurity in at-risk preterm-born infants, including in those colonised with pulmonary Ureaplasma spp. Since an adequately powered trial has been lacking, we conducted a double-blind, randomised, placebo-controlled trial to assess if the macrolide azithromycin improved survival without the development of physiologically defined moderate or severe chronic lung disease of prematurity in infants born at 

Authors' methods: Infants recruited from 30 neonatal units (median gestational age 27.0 weeks, interquartile range 25.3–28.6) requiring respiratory support within 72 hours of birth were randomised to intravenous azithromycin 20 mg/kg/day for 3 days followed by 10 mg/kg for 7 days or to placebo. Primary outcome was survival without development of physiologically defined moderate/severe chronic lung disease of prematurity at 36 weeks’ postmenstrual age. A total of 796 infants were required to detect 12% improvement in survival without development of moderate or severe chronic lung disease of prematurity, including 10% dropout, with two-sided α-level of 5% and 90% power. The primary outcome was analysed using three-level logistic regression to account for clustering of multiple births and participants within centres and was adjusted for gestational age as a fixed effect. Secondary outcomes included death, chronic lung disease of prematurity severity, treatment interaction with Ureaplasma spp. colonisation, days of invasive and days of non-invasive respiratory support, treatment for nosocomial infections, treated patent ductus arteriosus, severe intraventricular haemorrhage, necrotising enterocolitis, treated retinopathy of prematurity and emergence of azithromycin resistance in stool and respiratory samples. Quantitative polymerase chain reaction identified respiratory Ureaplasma spp. and antibiotic resistance genes. Safety was also monitored. Limitations include the (limited) missed oxygen reduction tests, inadequate collection of respiratory support data and lower-than-anticipated baseline sampling.

Project Status: Completed

URL for project: https://www.journalslibrary.nihr.ac.uk/programmes/hta/NIHR135886

Year Published: 2026

URL for published report: https://www.journalslibrary.nihr.ac.uk/hta/GJSK0401

URL for additional information: English

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: England, United Kingdom

DOI: 10.3310/GJSK0401

Organisation Name: NIHR Health Technology Assessment programme

Contact Address: NIHR Journals Library, National Institute for Health and Care Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK

Contact Name: journals.library@nihr.ac.uk

Contact Email: journals.library@nihr.ac.uk