A large patent ductus arteriosus (PDA) is associated with congestive heart failure, pulmonary hemorrhage, chronic lung disease (CLD), necrotizing enterocolitis (NEC) and intraventricular bleeding. Indomethacin is the first line of treatment for PDA. Failure of ductal closure with the first course of indomethacin is reported in 30-40% of infants, with a higher failure rate in infants weighing < 1000 gm. PDA ligation is associated with early postoperative hypotension, oxygenation failure and adverse neurodevelopmental outcome in preterm infants. The use of escalating doses of Indomethacin in the treatment of persistent PDA was found to be safe and decreased the need for PDA ligation without adverse effects in one observational study.We hypothesize that the use of an escalated dose of intravenous indomethacin will result in an increase in the probability of survival without need for surgical ligation of PDA as compared to a standard dose indomethacin in newborn infants < 29 weeks of gestational age with persistent PDA.