Primary Outcome Measures:
This is a retrospective chart review to look at the timing of using indomethacin and ibuprofen for PDA closure for infants admitted into the NICU of the University of Utah Hospital from 1/2007-8/2008. The purpose is to compare the outcomes of medical intervention in preterm infants if intervention occurs day of life 4 or less, or day of life 5 or greater, with the birthdate being counted as day of life 1. All infants born less than 1200 gms will be evaluated for whether or not an echocardiogram was done. If an echocardiogram was done that showed a PDA, data will be collected as to what medical interventions were done, at what age, and what were the results of the medical intervention. Infants will be stratified into birthweights <800 gm and 800-1200 gm.