Pregnancy complicated by patent ductus arteriosus

Patent ductus arteriosus (PDA) is a common congenital cardiovascular malformation, accounting for 5%–20% of congenital heart diseases. The ductus arteriosus is a vascular channel connecting the pulmonary artery and the descending aorta. During the fetal period, the lungs have no respiratory function, so most blood does not enter the lungs but is diverted from the pulmonary artery through the ductus arteriosus to the aorta. Its main function is to transport oxygen- and nutrient-containing blood from the right ventricle to the aorta to meet the metabolic needs of the fetus. After birth, with the development of pulmonary respiratory function and dilation of pulmonary vessels, the ductus arteriosus loses its function and gradually closes. If the ductus remains open after birth, it is termed patent ductus arteriosus.