In patent ductus aeriosus (PDA), the pulses are bounding, and pulse pressure is widened due to diastolic runoff through the ductus. PDA with left to right shunt is associated with necrotizing enterocolitis (NEC) due to bowel hypoperfusion. It is the most common acquired GI emergency in the newborn and it is most common in preterm infants, with an incidence of 10% in infants less than 1500 g. Pulmonary hemorrhage can occur in PDA from pulmonary over circulation with the pulmonary vascular resistance droping. Ref: Thilo E.H., Rosenberg A.A. (2012). Chapter 2. The Newborn Infant. In W.W. Hay, Jr., M.J. Levin, R.R. Deterding, J.J. Ross, J.M. Sondheimer (Eds),CURRENT Diagnosis & Treatment: Pediatrics, 21e.