What is it?

Atrioventricular septal defect (AVSD) is also referred to as an atrioventricular canal defect or endocardial cushion defect. It is characterized by a large hole in the heart between the chambers as well as misalignment of the valves that regulate blood flow within the heart.

How common is it?

AVSD is a rare heart defect, occurring between 2 to 3 in 10,000 births.

How is it managed?

When an AVSD is suspected, further evaluation includes a specialized evaluation of the fetal heart (“fetal echocardiogram”). As AVSD is frequently associated with other cardiac abnormalities and genetic syndromes, genetic counseling and testing are recommended. Prenatal consultations with pediatric cardiology, pediatric cardiothoracic surgery, and neonatology specialists are recommended to discuss the prognosis and management after birth. Prenatal care will be managed by a Maternal-Fetal Medicine specialist, an obstetrician with special training and expertise in high-risk pregnancies.


Management of AVSD generally involves surgery. Outcomes vary widely based upon the presence of other abnormalities or genetic syndromes.