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Truncus Arteriosus

No one wants to hear their baby has a congenital heart condition. At our Fetal Heart Program at the SSM Health Cardinal Glennon St. Louis Fetal Care Institute, we bring together the best cardiothoracic surgery, cardiology, neonatology and maternal-fetal medicine experts in the region to care for mothers and their babies. With advanced technologies and our experienced team, a congenital heart defect does not necessarily prevent your child from leading a normal life.

What Is Truncus Arteriosus?


Truncus arteriosus is a rare congenital heart defect where only one large blood vessel leads out of the heart instead of two, and branches to form both the pulmonary arteries (taking blood to the lungs) and the aorta (taking blood to the body). There is also a hole in the wall (ventricular septum) between the bottom chambers of the heart (the right and the left ventricle). This hole is called a ventricular septal defect (VSD) and allows oxygenated and unoxygenated blood to mix together.

If your doctor suspects a fetal heart anomaly after reviewing your routine ultrasound, he or she may request a fetal echocardiogram (echo), an ultrasound of the fetus’s heart. This safe, noninvasive test shows the structure of the heart and how it is functioning, which can help us confirm the diagnosis of truncus arteriosus and discuss possible options for treatment after delivery. Our fetal heart team will monitor your baby closely for the remainder of the pregnancy.

How Does Truncus Arteriosus Affect Delivery?

Most babies with truncus arteriosus can be delivered vaginally at full term unless otherwise indicated by your obstetrician. It is best for these babies to be delivered at a medical center where there is access to a team of pediatric cardiologists and neonatologists, along with an established Neonatal Intensive Care Unit (NICU).

How is Truncus Arteriosus Treated?

Most babies with truncus arteriosus need surgery in the newborn period. There are several components of the repair:

  • The pulmonary arteries are separated from the blood vessel leading out of the heart.
  • An artificial pulmonary valve is placed between the right ventricle and the pulmonary arteries.
  • The VSD is closed.
  • The large blood vessel is left in place as the aorta

After surgery your baby will require a stay in the Neonatal or Pediatric Intensive Care Unit (NICU or PICU) until they overcome any feeding and breathing difficulties. Your child will likely need lifelong follow-up visits with a cardiologist so the heart remains healthy.

Truncus Arteriosus repair

Because the pulmonary valve is artificial and does not grow with your child, this valve will need to be replaced periodically. In some cases the truncal valve may become leaky or blocked and require replacement, as well. However, the long-term prognosis remains good.

We are here to help – and we’re available 24 hours a day. Call us anytime to schedule an appointment, second opinion, or even if you have a question at (314) 268-4037. Our health care team at the Cardinal Glennon Fetal Care Institute strives to provide the best care possible for your child, allowing you to rest assured your little one’s heart is in good hands.

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