Clinical Research Directory

Inclusion Criteria: * Female patients aged 18 to 49 years. * Underwent cardiovascular surgery at our institution (e.g., coronary artery bypass grafting, heart valve repair/replacement, aortic surgery, congenital heart disease correction, heart transplantation). * Absence of heavy menstrual bleeding (HMB) or prolonged menstrual bleeding (\> 8 days) during the two consecutive menstrual cycles immediately prior to surgery. * Experienced at least one complete menstrual bleeding episode within the predefined postoperative follow-up window. * Receiving postoperative oral antiplatelet therapy (e.g., aspirin, clopidogrel) and/or oral anticoagulant therapy (e.g., rivaroxaban, warfarin). * Concurrent use or non-use of estrogen/progestin modulation therapy is permitted. Exclusion Criteria: * Previous diagnosis of congenital bleeding or coagulation disorders (e.g., hemophilia, von Willebrand disease, congenital coagulation factor deficiencies, congenital thromboembolic diseases). * History of endometrial ablation/resection, bilateral oophorectomy, or hysterectomy. * Current diagnosis of gynecological malignancies requiring chemotherapy, radiotherapy, or targeted therapy. * Pregnant or within 3 months postpartum prior to surgery or during the follow-up period. * Currently undergoing or planning to undergo in vitro fertilization (IVF) treatment. * Presence of psychiatric disorders, severe cognitive impairment, or other conditions precluding the effective completion of study assessments. * Failure or inability to provide written informed consent.