Ductus arteriosus and fetal echocardiography: Implications for practice

ABSTRACT

The ductus arteriosus (DA) is a crucial part of the fetal circulation, both in the normal fetus and in criticalcongenital heart disease (CHD). It allows shunting between the pulmonary and systemic circulations. In physiologicalprenatal conditions, the DA lets the majority of right ventricular output bypass the fluid-filled, highresistancelungs. The DA can cause hemodynamic compromise in the fetus and neonate when constricted orabsent (in isolation or in patients with CHD) and may lead to pre- or postnatal sequelae within other systemswhen forming part of a vascular ring. In CHD, the DA can be interrogated by fetal echocardiography to inferinformation regarding severity of pulmonary outflow tract obstruction, adequacy of the sub-pulmonary ventricleto supply pulmonary blood flow, and to predict the likelihood of atrial septum restriction in transposition of thegreat arteries. A good understanding of the DA is crucial for fetal cardiologists.