What is a PDA?
The ductus arteriosus is a small vessel every baby has before birth, connecting two major blood vessels so blood can bypass the lungs while they are not yet breathing air. It normally closes on its own within the first days after birth.
When it stays open — "patent" — extra blood recirculates through the lungs. In a full-term baby this is often small and causes no problems. In a premature baby, whose ductus is more likely to stay open and whose heart and lungs are less able to compensate, a PDA can matter a great deal more.
Signs that may point to it
How it is diagnosed and treated
An echocardiogram — including, where needed, at the cot side in the NICU — confirms the PDA and shows how much it is affecting the baby. Many close on their own or with medication in the newborn period and need no procedure.
Where closure is needed, transcatheter device closure is now possible even in very small and premature babies, sometimes under a kilogram, avoiding surgery in babies who are already medically fragile. Surgical ligation remains the right choice for some infants, particularly the smallest and sickest.