What is a Patent Ductus Arteriosus (PDA)?

Every baby is born with an open (patent) ductus arteriosus. This ductus arteriosus is a blood vessel that connects the two major blood vessels that leave the heart, the pulmonary artery and the aorta. Before birth blood bypasses the baby’s lungs because the mother’s lungs and the placenta do the work of “breathing” for the baby. The ductus arteriosus provides one route for blood to be directed away from the lungs of the fetus. After birth the baby’s lungs start functioning and the ductus arteriosus is no longer needed. In full-term babies, the ductus arteriosus usually closes shortly after birth. However, the closure of the ductus arteriosus may not occur as it should in premature infants. A PDA is not a type of heart malformation. It is a failure of normal transitions in blood flow to occur after delivery.

What happens if this blood vessel stays open?

If the ductus arteriosus remains open after birth it may allow blood to flow from the aorta back towards the lungs. Over time (days to weeks) a Patent Ductus Arteriosus, also referred to as a PDA, can allow too much blood to flow into your baby’s lungs. This excessive fluid in the lungs makes it harder for your baby to breathe. It can also cause your baby’s heart to work harder.

What are the signs and symptoms of a PDA?

Some small PDAs may not cause any symptoms in your baby. However, your baby may have one or more of the following signs when he/she has a significant PDA:

• Heart murmur
• Throbbing pulses
• Rapid or labored breathing
• Poor weight gain
• Tiring easily, especially during feeding
• Enlarged heart on x-ray with hazy lungs

How is a PDA diagnosed?

In some instances your baby’s doctors can tell that your baby may have a PDA based on the physical exam. Usually an ultrasound of the heart (called an ECHOCARDIOGRAM) is performed. An echocardiogram uses sound waves to create a picture of your baby’s heart and the blood flowing through it. This test is painless and is performed at your baby’s bedside. An echocardiogram can also diagnose problems with the formation of the heart that could cause a heart murmur.

How is a PDA treated?

In some instances, especially with small PDAs, doctors may wait to see if this blood vessel closes on its own. However, if your baby’s PDA is causing him/her difficulties it needs to be closed. Initially, your baby will be given a medicine called Indomethacin. If this first “course” is unsuccessful at closing the PDA a second and sometimes third course may be ordered.

Indomethacin can have side effects that need to be watched for closely. Most often, it may cause your baby’s urine output to decrease. This is usually a temporary problem that improves on its own.

If two or three courses of Indomethacin are unsuccessful in closing a significant PDA it may be necessary to surgically close it. This is termed “PDA ligation” and involves tying off the PDA or placing a clip on it. This type of surgery is performed by a cardiothoracic (heart) surgeon and requires general anesthesia. The surgery to close a PDA requires a small incision in the left side of the chest.

Will the PDA come back?

Once the PDA is closed with medicine there is a chance that it may re-open. This usually occurs within a few days to weeks. If your baby’s PDA is still open when he/she goes home from the NICU your baby will be followed by a pediatric cardiologist after discharge. There is a chance that the PDA may never close on its own. In this case, the cardiologist will decide when and how to close the PDA.

A PDA that is closed (clipped) surgically will not re-open.

A PDA does not predispose your baby to future heart problems.