Premature infants often suffer from respiratory problems due to their underdeveloped lungs. Over the past decade, many of these infants have been treated with inhaled nitric oxide — a treatment designed to ease breathing by widening blood vessels in the lungs. This week, an independent panel convened by the National Institutes of Health determined that the scientific data taken as a whole do not support the use of inhaled nitric oxide in the routine clinical care of premature infants born before the 34th week of pregnancy. Additional studies are needed to ascertain the short and long-term benefits and risks of this treatment.