Transcatheter closure of the PDA in the smallest of preterm infants (< 1000 grams) is being done in an increasing number of centers (1). Table Indomethacin Dosing Guidelines * Age at Dose 1 Dose 1 Dose 2 Dose 3 < 48 hours 0.2 mg / kg IV 0.1 mg / kg IV 0.1 mg / kg IV 2 - 7 days 0.2 mg / kg IV 0.2 mg / kg IV 0.2 mg / kg IV > 7 days 0.2 mg / kg IV 0.25 mg / kg IV 0.25 mg / kg IV * Dose intervals are based on urine output (see text).