Patent ductus arteriosus (PDA) is an extra blood vessel found in babies before
birth and just after birth.
In most babies who have an otherwise normal heart,
the PDA will shrink and close on its own in the first few days of life. If it stays
open longer, it may cause extra blood to flow to the lungs. Problems are most likely
if the PDA is large. Some smaller PDAs that don't close early will seal up on their
own by the time the child is a year old.
A patent ductus arteriosus (PAY-tent DUK-tus are-teer-ee-OH-sus) is more likely
to stay open in a premature infant,
particularly if the baby has lung disease. When this happens, doctors might need to
close the PDA.
What Happens in Patent Ductus Arteriosus?
The ductus arteriosus is a normal blood vessel that connects two major arteries
— the aorta and the pulmonary artery — that carry blood away from the
The lungs are not used while a fetus is in the womb because the baby gets oxygen
directly from the mother's placenta. The ductus arteriosus carries blood away from
the lungs and sends it directly to the body. When a newborn breathes and begins to
use the lungs, the ductus is no longer needed and usually closes by itself during
the first 2 days after birth.
If the ductus doesn't close, the result is a patent (meaning "open") ductus arteriosus.
The PDA lets oxygen-rich blood (blood high in oxygen) from the aorta mix with oxygen-poor
blood (blood low in oxygen) in the pulmonary artery. As a result, too much blood flows
into the lungs, which puts a strain on the heart and increases blood pressure in the
In infants born with other heart problems that decrease blood flow from the heart
to the lungs or decrease the flow of oxygen-rich blood to the body, the PDA may actually
help, and the doctor might prescribe medicine to keep the ductus arteriosus open.
What Causes Patent Ductus Arteriosus?
The cause of PDA is not known, but genetics might play a role. PDA is more common
in premature babies and affects twice as many girls as boys. It's also common among
babies with neonatal respiratory distress syndrome, babies with genetic disorders
(such as Down syndrome),
and babies whose mothers had rubella (also called German measles) during pregnancy.
What Are the Signs & Symptoms of Patent Ductus Arteriosus?
Babies with a large PDA might have symptoms such as:
a bounding (strong and forceful) pulse
not feeding well
shortness of breath
sweating while feeding
tiring very easily
How Is Patent Ductus Arteriosus Diagnosed?
If a PDA is suspected, the doctor will use a stethoscope to listen for a heart
murmur, which is often heard in babies with PDAs. Follow-up tests might include:
an EKG, a test that measures
the heart's electrical activity and can show if the heart is enlarged
an echocardiogram, a test that uses sound waves to diagnose heart problems. These
waves bounce off parts of the heart, creating a picture of the heart. In babies with
PDA, an echo shows how big the opening is and how well the heart is handling it.
How Is Patent Ductus Arteriosus Treated?
The three treatment options for PDA are medicine, catheter-based
procedures, and surgery. A doctor will close a PDA if the size of the opening
is big enough that the lungs could become overloaded with blood, a condition that
can lead to an enlarged heart.
A doctor also might close a PDA to reduce the risk of developing a heart infection
known as endocarditis, which affects the tissue lining the heart
and blood vessels. Endocarditis is serious and requires treatment with intravenous