The patent ductus arteriosus (PDA) is a condition where the gap between the two major blood arteries in the heart persists even after birth. Normally, this opening occurs before birth, which plays a critical role in fetal circulation. However, PDA in babies refers to a gap that remains open after delivery and can cause major health concerns.
Depending on the extent of the defect, symptoms, and the baby’s term, doctors may recommend monitoring, medicines, surgery, or catheterization to treat PDA.
Read on to know more about the causes, symptoms, complications, diagnosis, treatment options, and prevention of PDA in infants.
Causes Of PDA In Babies
The exact cause of patent ductus arteriosus is not known. Congenital heart defects can be due to fetal heart development issues, which could be influenced by environmental or genetic factors.
The following risk factors may increase the chance of having patent ductus arteriosus (1).
- Positive family history of heart defects
- Genetic conditions, such as Down syndrome
- Gender of the baby (female babies may have a higher risk of PDA than males)
- German measles (rubella) infection during pregnancy may lead to PDA since the virus moves through the placenta and damages blood vessels and fetal organs, such as the heart.
- Babies born at places on a high altitude may have an increased risk of PDA than babies born at places on a low altitude.
Some babies may not develop PDA despite the presence of risk factors, while some babies may have PDA without any discernible causes and risk factors.
Signs And Symptoms Of PDA
The condition shows symptoms depending on the severity of shunt across the patent ductus arteriosus. Symptoms also vary depending on the baby’s term and the size of the defect. A small PDA may go undetected until adulthood since it may not cause severe symptoms. In contrast, a large-sized defect shows signs and symptoms soon after birth.
Common signs and symptoms seen in infants with a large PDA may include (2):
- Sweating while feeding or crying
- Getting tired easily
- Rapid heart rate
- Fast breathing or breathlessness
- Slow growth due to poor eating
- Recurrent respiratory infections
You may consult a pediatrician for an exact diagnosis since these symptoms and signs can also be seen in other conditions.
Possible Complications Of PDA
A small-sized patent ductus arteriosus may not result in complications. A large-sized PDA, on the other hand, may cause excessive blood to circulate in the baby’s heart and lungs, leading to lung congestion and pulmonary hypertension. It may eventually result in heart failure.
Untreated large PDA may lead to the following complications in some babies (3).
- Heart failure may happen when the heart becomes enlarged and weakened due to patent ductus arteriosus. It is a chronic condition where the heart fails to pump enough blood.
- Pulmonary hypertension is high blood pressure in the lungs that can result in permanent lung damage. Large PDA may cause Eisenmenger syndrome that leads to irreversible pulmonary hypertension.
- Endocarditis is the inflammation of the inner lining of the heart. The risk of infective endocarditis is high in cases of structural heart defects.
Complications are more severe and cause permanent damages than PDA itself. Early interventions and medications could help resolve PDA before it causes adverse effects.
When To See A Doctor?
You may consider visiting a pediatrician if your baby has any of the following signs and symptoms.
- Getting tired easily when eating or playing
- Not gaining weight
- Breathlessness while eating or crying
- Rapid breathing or shortness of breath
You may explain your baby’s symptoms and signs to a pediatrician for an early appointment. Waiting for the regular checkup may not be ideal if your baby has symptoms of PDA.
Diagnosis Of PDA
An asymptomatic PDA case can be discovered during regular checkups since doctors can hear heart murmurs through the stethoscope. If the physical examination suggests a heart defect, doctors may order the following tests to confirm the diagnosis (4).
- Echocardiograms help evaluate the structure and function of the heart. Heart valve pathologies, enlarged heart chambers, and other heart defects can be assessed through echocardiography.
- Electrocardiogram (ECG) could help determine the rhythm of the heart and any conduction abnormalities.
- Chest X-ray could help visualize the chest cavity and identify any other conditions.
- Cardiac catheterization helps diagnose and also treat PDA.
These tests can be performed to confirm or exclude the diagnosis of various heart defects. Cardiac catheterization also provides treatment along with the diagnosis. This diagnosis method is chosen when the pediatric cardiac surgeon plans to diagnose and close the PDA simultaneously.
Treatment For PDA In Babies
Treatment options may vary depending on the term of the baby. The doctor may consider the following treatments for PDA in babies (5).
- Watchful waiting is recommended for premature babies since the PDA may close on its own. Term babies and children with small defects may also continuously be monitored without any intervention if there is no cause for concern.
- Paracetamol is also under vigorous trials as an alternate medical therapy for PDA closure with minimal adverse effects.
- Catheter procedures are preferred for term babies and children. Preemies are too small to undergo cardiac catheterization procedures. Coils or plugs depending on the size of the ductus may be placed to close the abnormal opening.
- Surgical closure is recommended if medication fails to close PDA, the defect is large or associated with complex anatomy and severe symptoms or complications are present. The surgical incision is made between ribs to access the heart and may require several days of hospitalization.
Taking preventive antibiotics for six months is recommended after the surgery to prevent infectious endocarditis. Periodic follow-up care is required for babies with PDA to monitor heart functions.
Prevention Of PDA
There is no exact way to prevent PDA in babies. Maternal health and lifestyle may play a role in the development of healthy hearts in babies. Perhaps taking measures to prevent preterm births may result in decreased incidence of PDA as this condition is known to occur more frequently in premature babies. The following measures may help reduce the risk of heart defects.
- Seek early prenatal care
- Consider preconception care, such as reducing stress and quitting smoking
- Follow a healthy diet containing iron, folic acid, vitamins, and minerals
- Do regular physical activity
- Avoid the use of tobacco, alcohol, and narcotics before and during pregnancy
- Get vaccinated to avoid infections, such as rubella
- Keep diabetes and other medical conditions under control
- Always take pregnancy-safe medications as per the doctor’s prescription
Can PDA Ever Be A Good Thing?
Yes. There are certain heart defects in which persistent ductus arteriosus is essential for adequate circulation of blood in the body. The structure is such that the PDA becomes essential for survival.
These are the babies born with a small or obstructed ventricle (either right or left) – one of the chambers of the heart. Therefore, they cannot tolerate the transition from fetal to neonatal circulation as described above at the time of birth and depend on the presence of a persistent ductus arteriosus for proper blood circulation. These conditions are called ductal dependent lesions.
As the PDA closes after birth these babies develop bluish discoloration, difficulty in breathing, cold extremities, and weak pulse. If this happens, it is an emergency requiring urgent medical attention. The doctors might need to give medicines to keep the PDA open until the ductal dependent lesion is definitively treated (6).
If you or your spouse has a family history of genetic conditions and heart defects, or you already have a child with any of these conditions, seek genetic counseling before planning a pregnancy.
Frequently Asked Questions
1. How common is PDA in babies?
PDA is more common in preterm infants and affects twice as many girls as boys (7). It develops in about ten percent of the babies born from 30 to 37 weeks of pregnancy, and 80 percent of the babies born from 25 to 28 weeks. On the other hand, the incidence of this heart condition is 90 percent of the babies born before 24 weeks (8).
2. At what age does a PDA close?
PDA functionally closes within 12 to 24 hours of birth with permanent closure within two to three weeks in healthy, full-term infants (9). In premature babies, the PDA closes within the first two years of life (10).
3. How soon after treatment will blood flow return to normal?
After surgery, the blood flow returns to normal almost immediately, provided no other heart defects are present in the baby (8).
4. How does patent ductus arteriosus affect blood flow?
When a baby has PDA, the oxygenated blood from the aorta mixes with deoxygenated blood in the pulmonary artery. This mix-up causes excessive blood flow into the lungs, putting an undue strain on the heart and increases blood pressure in the pulmonary arteries (7).
Although the exact cause of PDA in babies is not known, premature birth or genetic conditions might increase the risks of this condition. It is better to get proper treatment for your baby while the PDA is still small in size as it reduces the chances of complications such as heart failure or endocarditis. However, if you notice signs of breathlessness or difficulty in breathing, consult your child’s pediatrician immediately. In addition, seeking early prenatal care and following a healthy lifestyle can help prevent PDA in babies.
- The exact causes of patent ductus arteriosus in babies are not known.
- It can be due to genetic or environmental factors causing developmental issues of the fetal heart.
- Rapid heart rate, sweating, becoming tired while feeding, slow growth, and recurrent respiratory infections may indicate this condition.
- Consult a pediatrician if your baby gets tired easily, feels breathless, or doesn’t gain weight.
2. Patent Ductus Arteriosus; MedlinePlus; US National Library Of Medicine
3. Patent Ductus Arteriosus; St. Clair Hospital
4. Patent Ductus Arteriosus; University Of California San Francisco
5. Patent Ductus Arteriosus; Lucile Packard Children’s Hospital Stanford
6. Jae Young Lee; Clinical presentation of critical cardiac defects in the newborn; Korean Journal of Pediatrics
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