Background and Aims Emerging evidence suggests, that routine pharmacological or surgical closure of patent ductus arteriosus (PDA) is not beneficial for preterm infants. Informations about natural closure of ductus are lacking. Aim of the study was to evaluate untreated preterm infants with PDA.

Methods Retrospective observational study. Very low birth weight infants born during the 18 months period were enrolled. Only babies with severe signs of hemodynamically significant PDA were treated. All patients were followed until closure of PDA (clinically or echocardiographically approved).

Results 198 infants with mean birth weight 1113±690 grams and mean gestation age 28.4±7 weeks were eligible for the study. 22 (12%) died before discharge for morbidities directly unrelated to PDA. 13 patients were treated – 6 with ibuprofen and 8 were ligated. One neonate had residual flow through the PDA after ligation. 15 (7.5%) have been discharged with PDA. From them, 8 had spontaneous closure in the first year of corrected age and 1 in the second year. 6 infants have a small, hemodynamically nonsignificant PDA and are in cardiology follow up.

Conclusions Routine treatment of PDA should be abandoned. Chance of spontaneous closure is likely during the first year of corrected age. Cardiological and long term neurological follow up is needed for infants with PDA.