Background and aims: Recent pharmacological data suggest increased ibuprofen doses for treating patent ductus arteriosus (PDA). We evaluated the effectiveness and tolerance of a double dosed second ibuprofen course in our population.Methods: In our unit PDA management relies on systematic and repeated echocardiographic exams seeking strict treatment criteria (ductal diameter, left atrium/aortic root, left pulmonary artery diastolic blood flow). Persistent echocardiographic criteria after a first ibuprofen course induce a second course if not contra-indicated.We conducted a monocenter retrospective study by comparing two time periods: November 2004 to March 2006 and April 2006 to November 2009 where the second ibuprofen course doses respectively were 10-5-5 (IBU1) and 20-10-10 (IBU2) mg/kg. Baseline characteristics, treatment incidence, ductal closure and complications were compared between IBU1 and IBU2. Term-based subgroup analysis was performed (< or = 26 wks GA).Results: IBU1 and IBU2 populations were comparable. Ductal closure was more frequent for IBU2 (23/55,42%) than for IBU1 (3/23,13%) (p=0,02). Subgroup analysis confirmed this result only for infants = 26 wks GA.Incidence of mortality and common morbidities were comparable between IBU1 and IBU2. Among infants < 26 wks GA we observed a higher, although not significant, incidence of “death or BPD” for IBU2 vs IBU1 (37% vs 9%).Conclusions: This is the largest report of increased ibuprofen doses in infants < 28 wks GA with systematic echocardiographic assessment. In this study risk/benefit balance supports the use of a double-dosed second course of ibuprofen for PDA treatment only in infants = 26 wks GA.