Pulmonary Atresia

Overview

Pulmonary atresia is a congenital heart defect in which the pulmonary valve doesn’t form properly. The pulmonary valve connects the right side of the heart to the pulmonary artery, which carries blood to the lungs to get oxygen.

In this rare condition, instead of a normal valve with three leaflets that open and close, a thickened, abnormal valve forms that does not open, blocking the blood flow to the lungs.

Babies born with pulmonary atresia are unable to survive without an initial medication and eventual intervention or surgery, as they lack the proper connection between the right-side of the heart and the lungs. Babies born with pulmonary atresia don’t have enough oxygen in their blood to support the body’s needs.

What happens in pulmonary atresia?

The pulmonary valve is located between the right ventricle (the lower, right-sided pumping chamber) and the pulmonary artery, which carries blood to the lungs. Normally, when the right ventricle squeezes, it pumps oxygen-poor (also known as “blue blood”) across the pulmonary valve into the pulmonary artery and on to the lungs so that the blood can receive oxygen.

In a baby with pulmonary atresia, the pulmonary valve does not open, therefore blue-blood has to find a different route from the heart to the lungs.

Fetuses with pulmonary atresia demonstrate a unique circulation while in the womb in which they have extra connections, including:

• a patent foramen ovale (PFO, which is a hole between the upper chambers of the heart); and
• a patent ductus arteriosus (PDA, which is a connection between the pulmonary artery and aorta).

These connections allow the baby to maintain blood flow to their lungs while developing.

Newborns with pulmonary atresia depend on maintaining these connections after birth to allow blood to travel to the lungs for oxygen. While the PDA typically closes after birth, medications can be used to keep it open. Because the blood being pumped to the body is a mix of oxygen-poor and oxygen-rich blood, the newborn may have slightly lower oxygen levels at birth than a normal newborn.

Two Types of Pulmonary Atresia – With and Without a Ventricular Septal Defect (VSD)

In some cases, babies with pulmonary atresia also have an opening in the wall (septum) between the heart’s lower chambers (ventricles), providing another route for oxygen-poor blood to flow into the left side of the heart and get pumped out to the body. This hole is called a ventricular septal defect (VSD).

If there is no VSD, there will be less blood flowing through the right heart which prevents it from developing fully. At birth, this pumping chamber may be too small and underdeveloped, leaving the baby with only one functioning ventricle. This is a rare, life-threatening condition known as pulmonary atresia with intact ventricular septum (IVS) that requires immediate treatment at birth.

Cause and Prevalence

Pulmonary atresia occurs during the first eight weeks of pregnancy when the fetal heart fails to develop correctly. The cause is typically unknown.

The Centers for Disease Control and Prevention (CDC) estimates that about 1 in every 7,100 babies born each year in the United States are born with pulmonary atresia.

Diagnosis

Pulmonary atresia may be detected during pregnancy through a routine fetal echocardiogram (ultrasound of the fetal heart). A diagnosis during pregnancy enables your family and your healthcare team to plan ahead for the specialized treatment and cardiac expertise your baby will need at birth, optimizing outcomes. 

In some cases the condition isn’t diagnosed until after the baby is born. Symptoms in a newborn may include:

• Bluish tint to the skin, lips and nails (cyanosis) or pale skin, indicating a lack of oxygen in the blood
• A heart murmur (an abnormal sound caused by blood flow problems in the heart)
• Difficulty breathing or rapid breathing
• Fatigue
• Clammy skin
• Feeding problems

Specialized Prenatal Evaluation and Care

If pulmonary atresia is detected during pregnancy, prompt referral to a fetal cardiac center is important for further evaluation and proper treatment planning.

At Texas Children’s Fetal Center, we arrange for you to visit as quickly as possible to meet with a team of specialists experienced in diagnosing and treating rare congenital heart defects, including maternal-fetal medicine physicians (OB/GYNs specializing in high-risk pregnancies), fetal and pediatric cardiologists, fetal imaging experts, congenital heart surgeons, neonatologists, and genetic counselors.

You will undergo additional testing to help us gain more information about the structure and function of your baby’s heart.  

Following a thorough evaluation and assessment, our specialists will meet with you about the results, provide treatment recommendations, and answer any questions your family has, to help you make the most informed decisions regarding your baby’s care and treatment.

Mother and baby will be closely monitored during pregnancy. Because the fetus receives oxygen through the placenta during pregnancy, treatment for pulmonary atresia isn’t required until after birth.

Delivery

Delivery should take place at a center with the highest quality congenital heart program, ensuring the expertise and resources required at birth to treat babies with pulmonary atresia, including an advanced neonatal and cardiovascular intensive care unit (NICU and CICU).

Delivery and postnatal care should be carefully planned and coordinated. Our Fetal Center team works closely with Texas Children’s Heart Center, seamlessly transitioning your baby’s care at delivery to this national leader in pediatric cardiology and heart surgery. Here, the heart specialists treating your newborn have been an integral part of their care team since before birth.

Following delivery at Texas Children’s Pavilion for Women, newborns are transferred to the Cardiac Intensive Care Unit (CICU)  to receive the highest level of care available for critically ill newborns with congenital heart disease.

Treatment

Treatment is required after birth to improve blood flow to the lungs and meet the baby’s oxygen needs. 

The type and timing of treatment will depend on the severity of the condition, the baby’s symptoms, overall health, and any other defects present.

Treatment strategies for pulmonary atresia include:

• Medication – Prostaglandins (PGE) are a medication given to babies through an IV which keeps the ductus arteriosus from closing. This enables blood to continue to flow to the lungs for oxygen until a more permanent treatment strategy is determined.
• Cardiac catheterization (balloon atrial septostomy, perforation of the pulmonary valve or PDA stent) – A thin, flexible tube (catheter) with a balloon on the end is inserted into a blood vessel in the groin and guided into the heart and through the foramen ovale. The balloon is inflated to enlarge this opening, improving the mixing of deoxygenated and oxygenated blood and the flow into the left-side of the heart. In some cases, cardiac catheterization can be used to create an opening in the pulmonary valve, or alternatively insert a stent (small metal tube) to keep the ductus arteriosus open, preventing or delaying the need for open heart surgery so soon after birth.
• Heart surgery – to repair or replace the pulmonary valve, enabling blood to flow directly from the right ventricle to the lungs. If the baby has a ventricular septal defect (VSD), the defect will be closed. If no VSD is present and the baby’s right ventricle is very underdeveloped, a series of heart surgeries will be needed during the first few years of life to enable the child’s heart to function with only one ventricle (pumping chamber).  
• Heart transplant – considered in select cases in which the baby’s heart is too damaged to repair.

Postnatal Care Team

Depending on the severity of the condition, your baby’s postnatal care team may include:

• a neonatologist
• a pediatric cardiologist
• a pediatric congenital heart surgeon
• a pediatric cardiovascular anesthesiologist
• a pediatric cardiac intensivist  

Long-Term Care

Babies born with pulmonary atresia require life-long monitoring by cardiologists experienced in the treatment of congenital heart defects.

At Texas Children’s Heart Center, our pediatric cardiologists follow your child through adolescence, seamlessly transitioning their care at adulthood to our Adult Congenital Heart Disease program. 

Why Texas Children’s Fetal Center?

• A single location for expert maternal, fetal and pediatric care. Texas Children’s Hospital offers mothers and babies the specialized care required for the diagnosis and treatment of congenital heart conditions all in one location, for highly coordinated care and treatment planning.
• A skilled, experienced team with proven outcomes. We have a dedicated team of maternal-fetal medicine specialists, fetal imaging experts, fetal and pediatric cardiologists, congenital heart surgeons, neonatologists and others who work in concert to care for you and your baby every step of the way, using proven protocols we’ve developed over the years. With their combined expertise and unified approach, this team offers the best possible care for babies with pulmonary atresia.
• We care for your child’s cardiac needs at every stage of life, from fetus to adulthood. Our comprehensive approach starts with your first prenatal visit and continues through delivery, postnatal care, childhood and adulthood, thanks to one of the nation’s leading teams of fetal, pediatric and adult congenital heart specialists.

Texas Children’s – #1 in the Nation for Pediatric Cardiology and Heart Surgery

Our Fetal Cardiology Program is a collaboration between Texas Children’s Fetal Center and Texas Children’s Heart Center, ranked #1 in the nation for pediatric cardiology and heart surgery by U.S. News & World Report, with outcomes among the best in the nation.

Volumes and Outcomes

• Volumes and outcomes for patients treated by the Fetal Cardiology program
• Texas Children’s Heart Center Outcomes

In the News

• Texas Children’s ranked No. 1 in heart care​
• Best hospitals for children with severe congenital heart disease
• 10 ways to get your child the best heart surgeon

Videos

• Critical congenital heart disease screening now required for all newborns in Texas
• Texas Children’s Fetal Center: Our care began before she/he was born

Research and Clinical Trials

Texas Children’s, together with our partner institution Baylor College of Medicine, constantly strives to seek new and better treatments for babies with congenital heart defects.

Learn more about our fetal cardiology research.

For additional information, please contact the Cardiovascular Clinical Research Core at 832-826-2064 or email sandrea@texaschildrens.org.