Successful Antenatal Embolization of a Complex Pulmonary Arteriovenous Malformation in the Third Trimester of Pregnancy: A Case Report

<b>Background:</b> A pulmonary arteriovenous malformation (PAVM) is an abnormal connection between the pulmonary arterial and venous systems, resulting in a pathologic right-to-left shunt. PAVMs worsen during pregnancy due to physiologic changes, yet no treatment guidelines exist for newly diagnosed PAVMs in pregnancy.<b>Case:</b> We report a case of a previously asymptomatic 19-year-old G1 who was incidentally found to have a low oxygen saturation during routine prenatal care at 34 5/7 weeks of gestation. She was diagnosed with a complex, left-sided PAVM. Through the close collaboration of the interventional radiology and high-risk obstetric teams, antenatal embolization was successfully performed, allowing for the prolongation of pregnancy. The patient experienced spontaneous rupture of membranes at 36 1/7 weeks and underwent a successful Cesarean delivery at this time.<b>Conclusion:</b> Embolization of a complex PAVM in the third trimester of pregnancy was successfully and safely achieved by a skilled multidisciplinary team. In comparable clinical scenarios, clinicians should carefully assess maternal and fetal risks-such as neonatal prematurity, radiation exposure, and PAVM-related complications-to guide optimal management.