The aorta moves blood away from the heart to the rest of the body. The pulmonary artery moves blood from the heart to the lungs.
Before birth and for a few days after birth, the pulmonary artery and the aorta are connected by a short blood vessel called the ductus arteriosus.
Because a fetus doesn't breathe, very little blood needs to go to its lungs
The fetus has a ductus arteriosus so blood can bypass the lungs
After birth, the ductus needs to close quickly so blood can flow normally, first through the lungs and then to the body.
What is patent ductus arteriosus (PDA)?
Patent is a medical term that means "open." In patent ductus arteriosus (PDA), the ductus arteriosus doesn't close.
Premature babies are more likely to have PDA
Often there aren't any symptoms, but a doctor listening with a stethoscope may hear a heart murmur (an unusual sound between heartbeats)
Doctors treat PDA with medicine and sometimes surgery
Babies with PDA have a higher than normal chance of getting a heart infection
Patent Ductus Arteriosus: Failure to Close
The ductus arteriosus is a blood vessel that connects the pulmonary artery and the aorta. In the fetus, it enables blood to bypass the lungs. The fetus does not breathe air, and thus blood does not need to pass through the lungs to be oxygenated. After birth, blood does need to be oxygenated in the lungs, and normally the ductus arteriosus closes quickly, usually within days up to 2 weeks.
In patent ductus arteriosus, this connection does not close, allowing some oxygenated blood, intended for the body, to return to the lungs. As a result, the blood vessels in the lungs may be overloaded and the body may not receive enough oxygenated blood.
What causes PDA?
Doctors aren't sure why the ductus arteriosus doesn't close as it should in some babies, but PDA is much more common in premature babies Premature Baby "Pre-" means before, and "mature" means fully grown. A premature baby is born too early. A full pregnancy lasts 37 to 40 weeks, so a premature baby is born anytime before the 37th week of pregnancy... read more .
What are the symptoms of PDA?
If the PDA is small, a baby may not have any symptoms. If the PDA is larger, your baby may have:
Low blood pressure
Slow or poor growth
How can doctors tell if my baby has PDA?
Doctors suspect PDA if they hear a certain type of heart murmur. Doctors confirm the diagnosis by:
Echocardiography Echocardiography and Other Ultrasound Procedures Echocardiography can be used to detect abnormalities in heart wall motion and to measure the volume of blood being pumped from the heart with each beat. This procedure can also detect abnormalities... read more (ultrasound of the heart)
Doctors will also do:
ECG/EKG Electrocardiography Electrocardiography is a test that measures your heart’s electrical activity. It's quick, painless, and harmless. The results of that test are shown in an electrocardiogram. It looks like a... read more (electrocardiography—a painless test that measures the heart’s electrical currents and records them on a piece of paper)
How do doctors treat PDA?
Treatment depends on:
The size of the PDA
How premature the baby is
What symptoms the baby has
Sometimes a small PDA will close on its own. This usually happens before a baby is 1 year old. If doctors need to treat your baby's PDA, they may:
Give your baby certain medicines that can help close the ductus
Place a long, thin tube (catheter) in the baby's heart and use a device to close the ductus
If the PDA is unusually large, do surgery to close the ductus