What is Patent Ductus Arteriosus?
Patent Ductus Arteriosus (PDA) is a condition where the tube of the ductus arteriosus, a fetal artery in the heart, remains open at birth and does not close. This opening causes extra blood to be pumped into the lung arteries, which may cause the heart and lungs to be overworked.
The ductus arteriosus is a normal structure in the heart of the fetus. It is a tube that connects the two major blood vessels of the heart, the aorta (which brings blood to the body) and the pulmonary artery (which brings blood to the lungs).
Before a baby is born, blood cannot get oxygenated in the baby's lungs as they are not yet breathing. Instead, it must be oxygenated by the mother at the placenta. The tube of the ductus arteriosus allows the oxygen-rich blood that would normally travel to the baby's lungs to flow from the pulmonary artery to the aorta and back to the mother.
After birth, the ductus arteriosus is no longer needed, and typically closes on its own during the first few days of life. When the tube fails to close completely, it is called a patent (“open”) ductus arteriosus or PDA.
Symptoms of PDA depend upon the size of the remaining tube. With a tiny PDA, there may be no symptoms at all, and it might not be discovered for many years, if ever. With very large PDAs, the baby can be very ill soon after birth.
Signs & Symptoms of Patent Ductus Arteriosus
If your baby has only a small patent ductus arteriosus, they might not have any symptoms. The patent ductus arteriosus might not even be diagnosed unless your doctor hears a heart murmur (usually not in the newborn period). But if it’s larger, your baby may have the following symptoms:
- Rapid breathing
- Heavy breathing
- Congested breathing
- Trouble feeding
- Poor weight gain
- Rapid heartbeat
All PDA symptoms are related to blood being diverted from the aorta (body) into the pulmonary artery (lungs). The amount of blood being diverted determines the presence and severity of the baby's PDA symptoms.
What Causes Patent Ductus Arteriosus?
There is no known cause of PDA other than prematurity and some genetic abnormalities like Down Syndrome. In premature infants, the muscles lining the inside of the ductus arteriosus tube may not be fully formed. In that case, the tube will be unable to close on its own after the baby is born. In full term babies, the muscle layer may partial close the ductus arteriosus, which typically results in a much smaller PDA.
- A PDA occurs in less than one-tenth of one percent in full-term (40 weeks) babies but may occur in about 20 percent of babies born at 32 weeks, and in 90 percent of those born at 26 weeks.
- PDA is about twice as common in girls than in boys.
- Mothers who have German measles during their pregnancy are more likely to have a baby with a heart defect, including PDA.
- Newborns, particularly premature infants, with lung complications after birth are more likely to have a PDA.
If a PDA is treated, then your baby’s long-term outcome is normal. Most children have no need for additional medication, chronic medical care or surgeries. But if left untreated, PDA can be associated with several potentially life-threatening complications.
Complications for large, unrepaired PDA may include:
- Congestive heart failure in infancy - blood is diverted from the body to the lungs, making it harder for the baby to breathe, and difficult for the baby to exert themselves (crying/eating). These babies fail to gain weight, which often leads to a PDA diagnosis.
- Pulmonary edema - with too much blood flowing to the lungs, water can leak out of the blood vessels into the air spaces of the lungs, making it difficult for the baby to breathe.
- Pulmonary hypertension - large patent ductus arteriosus allows too much blood to circulate through the lungs, which causes blood pressure to rise to very high levels. Untreated, this can cause permanent lung damage.
In a smaller PDA, not as much blood can travel to the lungs, and patients are usually not symptomatic. Complications from smaller PDAs include:
- Endocarditis – due to turbulent flow through the PDA, the smooth lining of the ductus tube can be disrupted. Bacteria in the blood, especially associated with dental procedures, can stick to its roughened surface and cause an infection of the blood vessels.
- Chest pain - though considered rare, adults with undiagnosed PDA may develop chest pain when cholesterol blockages form in the coronary arteries, as the PDA "steals" some of the blood flow from the coronaries.
If you have a PDA and are considering getting pregnant, speak with your physician. Most of the time, pregnancy is low risk in patients with PDA unless they have pulmonary hypertension or heart failure. Consult your healthcare provider or a pediatric cardiologist to see if high-risk obstetric care or a procedure to close the PDA will be needed.
Routine prenatal care during pregnancy is the main way to prevent premature birth and PDA in your baby. Stay up-to-date on vaccinations, including against rubella before you become pregnant, since this infection raises your baby’s PDA risk.
Take care to ensure a healthy pregnancy with the following steps:
- Prenatal care - medical checkups and screening tests help monitor the health of you and your baby during pregnancy.
- Regular exercise and a healthy diet - include foods rich in protein, iron, calcium, and folic acid to meet your nutrition needs during pregnancy. Healthy pregnant women should get at least thirty minutes of moderate-intensity aerobic exercise most days of the week. Research also suggests women who are active during pregnancy have a lower risk of pre-term delivery.
- Avoid infection - as certain infections, such as influenza or COVID-19, raise your risk of premature birth and pregnancy-related complications.
- Keep underlying medical conditions under control - including if you have asthma, type 2 diabetes, or high blood pressure, which are associated with a higher risk of pregnancy complications that could lead to premature birth. Manage chronic health conditions and get care before you become pregnant.
Trust NewYork-Presbyterian for Patent Ductus Arteriosus Care
NewYork-Presbyterian Morgan Stanley Children’s Hospital and NewYork-Presbyterian Komansky Children’s Hospital have an integrated Congenital Heart Center which is one of the largest and most preeminent pediatric cardiology and cardiac surgery centers in the nation.
We provide pediatric and adult patients with patent ductus arteriosus and other heart defects with the latest treatment options. Contact us now to schedule an appointment.