Basics -- Developmental Anatomy of the Ductus Arteriosus -- Regulation of Smooth Muscle Contraction -- Prostaglandin Metabolism and Effects of Inhibitors -- Postnatal Circulatory Adaptation -- Epidemiology of Persisting Ductus in Preterm Infants -- Clinical Features -- Persisting Ductus Arteriosus and Respiratory Problems -- Influence on Mesenteric Perfusion and Necrotizing Enterocolitis -- Per…