Preterm patent ductus arteriosus: should we treat it?

Debate about the importance of the preterm patent ductus arteriosus (PDA) remains unresolved. Ultrasound studies of PDA have suggested that the haemodynamic impact may be much earlier after birth than previously thought, but we still do not know when to treat a PDA. Studies that have tested symptomatic or pre-symptomatic treatment are mainly historical and have not tested the effect of no treatment. Prophylactic treatment is the best studied regimen, but improvements in some short-term outcomes do not translate to any difference in longer term outcomes. Neonatologists have been reluctant to engage in trials that test treatment against not treating at all or very rarely. Targeting treatment on the basis of the early post-natal constrictive response of the duct is currently being tested as a possible strategy.