Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome is a type of congenital heart defect. This defect causes the left side of the heart to be too small and weak to adequately pump blood throughout the body. The lack of oxygen-rich blood causes babies with hypoplastic left heart syndrome to have lower oxygen levels than normal, which may give the skin a bluish tint.

Hypoplastic Left Heart Syndrome Treatment: Why Choose Us?

Hypoplastic left heart syndrome is life-threatening without surgical treatment. Our high-risk pregnancy experts at the Fetal Care Center work closely with heart specialists at the Fetal Heart Center to ensure your baby receives world-class care. 

Our pediatric heart surgeons are experts at treating babies with hypoplastic left heart syndrome. U.S. News & World Report rates the pediatric heart surgery program at St. Louis Children’s Hospital as one of the nation’s best. In addition, The Heart Center is part of the National Pediatric Cardiology Quality Improvement Collaborative, a multicenter study of outcomes in patients with hypoplastic left heart syndrome.

About Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome is a rare birth defect, affecting about 1 out of every 4,300 newborns. 

The left side of the heart normally pumps blood into the aorta, the artery that carries blood to the rest of the body. In babies with hypoplastic left heart syndrome, the left side of the heart is underdeveloped. As a result, the heart cannot pump enough blood to meet the body’s needs. 

Babies with this condition often have several heart defects, including:

  • Underdeveloped left ventricle: The heart’s lower pumping chamber
  • Small or closed aortic valve: The valve separating the aorta and the left ventricle
  • Small or closed mitral valve: The valve separating the atrium and ventricle, or the heart’s left chambers 

Causes of Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome has no known cause. However, some congenital heart defects may be inherited. Our genetic counselors can give you more information.

Diagnosing Hypoplastic Left Heart Syndrome

Our ultrasound experts use the latest ultrasound technology to detect heart problems in unborn babies. Our maternal-fetal medicine specialists are with you to quickly provide information about your unborn baby’s heart condition. Our specialists perform more than 5,000 obstetrical and gynecological ultrasounds every year. This high volume and experience helps us detect heart problems early. 

In addition to ultrasounds, your doctor also may order:

  • Fetal echocardiogram: This ultrasound imaging test assesses the structure and health of your unborn baby’s heart.
  • Fetal magnetic resonance imaging (MRI): This imaging procedure uses a magnetic field (not radiation) to provide detailed information about your unborn baby’s heart and lungs. This test is safe for your unborn baby. 

Learn more about high-risk pregnancy tests.

Treating Hypoplastic Left Heart Syndrome

Throughout pregnancy, you undergo regular ultrasounds to check the development of your baby’s heart. You also meet with heart specialists at the Fetal Heart Center to discuss treatment options. 

Because your baby needs specialized medical and surgical care, we recommend giving birth at a hospital like the Women & Infants Center that specializes in high-risk pregnancies. After delivery, your baby receives advanced medical care in the cardiac intensive care unit (CICU) at St. Louis Children’s Hospital. 

Babies born with hypoplastic left heart syndrome usually undergo a series of heart surgeries performed over a period of two to three years. Surgical procedures include:

  • Norwood procedure: Your doctor creates a new aorta for your baby and connects it to the heart’s right ventricle, or chamber. This procedure allows the right side of the heart to pump blood to both lungs and the rest of the body. This surgery typically occurs within a week of your baby’s birth.
  • Glenn shunt procedure: Your doctor connects the vein that carries deoxygenated blood from the upper body to the pulmonary artery. This step reduces stress placed on the right side of the heart from the Norwood procedure. This surgery typically occurs when a baby is 4 to 6 months old. 
  • Fontan procedure: Your doctor connects the pulmonary artery to the vein that carries deoxygenated blood from the lower body. This step allows all of the body’s deoxygenated blood to go to the lungs, bypassing the heart. This surgery typically occurs when a child is 2 to 3 years old.

After surgery, your baby receives advanced medical care in the Inpatient Heart Center at St. Louis Children’s Hospital. 

Some babies with hypoplastic left heart syndrome need a heart transplant. The heart transplant program at St. Louis Children’s Hospital is one of the most active pediatric heart transplant programs in the country.

Contact Us

To make an appointment with a Washington University fetal heart specialist at the Women & Infants Center, call [Dynamic_Phone_Number].