METHODS	Forty preterm infants with gestational ages of less than 33 weeks , with respiratory distress syndrome ( RDS ) and echocardiographically confirmed PDA , were randomly assigned at days 2 to 3 of life to receive either intravenous indomethacin 3 x 0.2 mg/kg at 12 hour intervals or intravenous ibuprofen 1 x 10 mg/kg , followed by 5 mg/kg 24 and 48 hours later .\