Pseudoaneurysm formation often occurs when there is inadequate sealing at an arterial puncture site. We present the case of a 27-year-old primigravida with rheumatic heart disease and a history of mitral valve replacement on anticoagulants who experienced recurrent episodes of postpartum hemorrhage (PPH). Despite conservative management and adjustments to anticoagulant therapy, the bleeding persisted. Further investigations revealed a small pseudoaneurysm originating from the left uterine artery. Bilateral uterine artery embolization (UAE) using polyvinyl alcohol particles was successfully performed. The patient’s condition improved, and she was discharged on a carefully regulated medication regimen. This case highlights the importance of considering rare causes of PPH in high-risk patients, such as uterine artery pseudoaneurysm. Anticoagulants could be a potential contributor of its spontaneous rupture. Prompt diagnosis and appropriate intervention, such as UAE, can effectively manage PPH and prevent adverse outcomes.