Patent Ductus Arteriosus
This is an extra blood vessel that is a normal part of the fetal circulation. Every baby has this blood vessel prior to birth and it's purpose is to shunt blood away from the lungs. When a baby is born and his lungs fill with air, this blood vessel starts to close. The "PDA" commonly closes in the first 24-48 hours of life. In some cases, it may remain open for a longer period, or may remain open permanently.