Abstract: BACKGROUND:Early empiric antibiotic exposure appears to negatively influence feeding tolerance in preterm infants. However, the effect of prolonged antibiotic treatment is unknown. The objective of this study was to investigate whether prolonged antibiotics impact the time to full enteral feed in infants less than 29 weeks of gestational age with negative blood cultures. METHODS:Retrospective data for infants less than 29 weeks gestation age were retrieved from the PEARL-Peristat perinatal registry in Qatar. Exclusion criteria were major congenital anomalies, conditions requiring surgery in the first 10 days of life, positive blood cultures in the first 48 hours of life, and death within the first week of life. Antibiotic courses were categorized as prolonged if continued more than 48 hours. The primary outcome was the duration of total parenteral nutrition. RESULTS:Of 199 study infants, 185 (92.9%) underwent antibiotic treatment for > 48 hours despite negative blood cultures. The median duration of parenteral nutrition was not significantly different between the prolonged and short antibiotic groups (25 and 22 days, respectively; p = 0.139). Infants with prolonged antibiotic courses experienced non-significantly higher levels of necrotizing enterocolitis (7.1% and 18.4%, respectively), bronchopulmonary dysplasia (28.6% and 45.4%, respectively), and retinopathy of prematurity (14.3% and 38.4%, respectively). There were no differences in the late-onset sepsis rate (78.6% and 82.1%, respectively) and the in-hospital death rate (7.1% and 7.6%, respectively). CONCLUSIONS:Prolonged antibiotic treatment in infants less than 29 weeks gestation with negative blood cultures has no significant impact on the time to full enteral feed.