Patent ductus arteriosus (PDA) is a common problem for premature babies. Indomethacin, traditionally the treatment of choice for PDA closure, varies in effectiveness and can have serious side effects, such as intraventricular cerebral hemorrhage and decreased mesenteric and renal blood flow. Researchers abroad are examining the efficacy and safety of ibuprofen as an alternative PDA therapy. Their findings have been promising and indicate the need for clinical trials in the U.S.