Ductus arteriosus (DA) closure occurs within 96 hours in >95% of neonates >1500 g in birth weight (BW). The prevalence and postnatal age of spontaneous ductal closure in neonates 34% of ELBW neonates and is predicted by variables related to maturation, for example, EGA and an absence of HMD, whereas indomethacin failure could not be predicated.