“The reported incidence of PDA in term neonates is only 1 in 2,000 births, accounting for 5%–10% of all congenital heart disease.6 The incidence of PDA in preterm neonates is far greater, with reports ranging from 20%–60% (depending on population and diagnostic criteria).3 The increased incidence of PDA in the preterm infant is attributable to the lack of normal closure mechanisms due to immaturity. Gestational age and weight are intimately linked to PDA in preterm neonates. Specifically, PDA is present in 80% of infants weighing less than 1,200 g at birth, compared to 40% of infants weighing less than 2,000 g at birth.1,7 Furthermore, symptomatic PDA is present in 48% of infants with a birth weight of less than 1,000 g.”
National Library of Medicine (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3462096/)