Fetal Cardiac Intervention


Fetal cardiac intervention is surgery to repair a serious congenital heart defect before a baby is born.

It may be performed for several reasons, including if the fetus has:

Hypoplastic left heart syndrome (HLHS) with intact atrial septum

HLHS with critical aortic stenosis (severely obstructed aortic valve)

Complete heart block with hydrops (swelling of the fetus)

In babies with HLHS, the goal of fetal cardiac intervention is to allow the fetus to develop longer and be more stable at birth.

About the procedure

Fetal cardiac intervention is complex surgery that is performed in the hospital. The mother and fetus are sedated, and an incision is made in the mother’s abdomen, similar to that for a cesarean section. An incision is made in her uterus, exposing the fetus. Guided by ultrasound images, a specialized needle is inserted into the heart of the fetus. A tiny tube, or catheter, with a balloon attached to it is introduced into the heart. The balloon is inflated to expand the valve and allow blood to flow. After the procedure, the fetus is returned to the mother’s uterus. Amniotic fluid is replaced, and the uterus and abdomen are closed.


Like all major surgery, fetal cardiac intervention has risks. These include bleeding, preterm labor and delivery, emergency cesarean section delivery and harm to the fetus.

After the procedure

The mother will remain in the hospital several days to a week after the procedure. Cesarean delivery will be required for the current and future pregnancies. The mother probably will need to take medication to prevent early labor, and she will be closely monitored throughout the rest of the pregnancy. Fetal echocardiography and ultrasound examinations will be performed several times before birth.

Children with HLHS have at least three surgeries during the first three years of life.