Hypoplastic Right Heart Syndrome



The heart forms in the fetus early in pregnancy. It is unclear why the heart does not develop as it should. It may be a mix of changes in the genes and things in the fetus and the pregnant person's environment.

Risk Factors

People with a family history of similar heart issues can have a higher risk of HRHS.



HRHS can cause poor blood flow to the lungs. This can lead to:

  • Blue tint to skin and lips
  • Rapid breathing
  • Feeding problems

Symptoms of HRHS may get worse over the first few weeks of life.


HRHS may be diagnosed before birth. The doctor may see a difference in the right side of the heart during a prenatal ultrasound. A fetal echocardiogram may be done to confirm HRHS.

After birth, HRHS may be suspected based on the baby’s symptoms. The doctor may also hear a heart murmur. A doctor who treats heart issues in children may need to see the baby.



The goal of treatment is to help blood flow better. Babies with HRHS will need treatment shortly after birth. If HRHS was detected before birth, specialists will help watch and treat the baby right after birth. The full treatment plan will depend on the baby’s overall health and parents' choices.

Medicine may be given shortly after birth to support the baby until surgery can be done. Surgery choices include:

Blalock-Taussig Shunt

A shunt will increase the flow of blood to the lungs. It is often done within the first few days of life.

A shunt is a tube that creates a new path for blood flow. This shunt can increase the flow of blood to the lungs by making a path from the aorta to the main artery to the lungs. The aorta is a major artery that carries blood away from the heart to the rest of the body.

The shunt is a temporary step. It will improve oxygen supply to the body and ease some symptoms.

Glenn and Fontan Procedures

The blalock-taussig shunt will not be as helpful as the child grows. Glenn and Fontan procedures may be done once the child is around 3 months of age. The procedures are often done in two surgeries.

The Glenn shunt makes a pathway between the superior vena cava and the main artery to the lungs. The superior vena cava is a large vein that collects blood from the body and sends it back to the heart. This shunt sends some of the blood right to the lungs instead of moving it all through the heart.

The Fontan or Fontan completion is done when the child is 3 to 5 years of age. This surgery makes a connection between the inferior vena cava and superior vena cava. The inferior vena cava also collects blood from the body. This last connection means more of the blood returning from the body will go straight to the lungs and bypass the right side of the heart.

Heart Transplant

The shunts can increase oxygen in the blood. This should help with most symptoms. Surgery cannot fix the ventricle problem. The left side of the heart will at some point have a hard time keeping up. The heart will need to be replaced through a heart transplant.

A heart transplant may be done instead of the Glenn and Fontan procedures or later in adulthood.


There are no known steps to prevent HRHS. Proper prenatal care can decrease the risk of some heart defects.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.