A bicuspid aortic valve is an aortic valve that only has two leaflets, instead of three. The aortic valve allows oxygen-rich blood to flow from the heart to the aorta. It prevents the blood from flowing back from the aorta into the heart. An abnormal aortic valve develops during the early weeks of pregnancy, when the baby's heart develops.
Review Date 7/7/2020
Updated by: Thomas S. Metkus, MD, Assistant Professor of Medicine and Surgery, Johns Hopkins University School of Medicine, Baltimore, MD. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.