Fetal Echocardiography Practice Test 2026 – Complete Exam Prep Guide

Whether systemic perfusion in a fetus with congenital heart disease is ductus dependent depends on the anatomy of the heart and great vessels. If the body would not receive adequate blood flow without the patent ductus arteriosus, then systemic circulation is ductus dependent. This situation typically arises when there is obstruction or hypoplasia of the left-sided outflow, such as critical aortic stenosis or hypoplastic left heart, or arch anomalies that prevent adequate systemic flow unless the ductus remains open. In these cases, the PDA provides the necessary route for blood to reach the body, so closure would compromise systemic perfusion. Fetal sex, maternal age, or placental insufficiency do not determine ductus dependence; they don’t define the specific anatomic requirement for the ductus to supply the systemic circulation.