A patent ductus arteriosus (PDA) complicates the clinical course of preterm infants, increasing their risks of developing chronic lung disease (CLD), necrotizing enterocolitis (NEC), and intraventricular hemorrhage (IVH). Indomethacin is used as standard therapy to close a PDA, but is associated with reduced blood flow to the brain, kidneys and gastrointestinal tract. Ibuprofen, another cyclo-oxygenase inhibitor, may be as effective as indomethacin, with fewer side effects.