Objective  To investigate the incidence and adverse effects of abnormal uterine bleeding (AUB) during oral anticoagulation therapy in women with thrombophilia.

  Methods  The female patients with thrombophilia who received oral anticoagulation therapy with rivaroxaban or warfarin in the Department of Hematology of Peking Union Medical College Hospital from January 2013 to May 2023 were selected as the study subjects. Their demographic characteristics, disease related data and AUB before and after anticoagulant therapy were retrospectively collected. The patients were divided into rivaroxaban treatment group and warfarin treatment group according to anticoagulant drugs. The generalized estimating equation was used to analyze the difference in the incidence of AUB before and after anticoagulant therapy, and explore the effect of different anticoagulant therapy on AUB.

  Results  A total of 106 female patients with thrombophilia were included, and we found that oral anticoagulation significantly increased the incidence of AUB (56.6% vs. 26.4%, P < 0.001), predominantly characterized by excessive menstruation (48.1%) and prolonged periods (21.7%). Rivaroxaban was more likely to cause AUB than warfarin (OR=3.3, 95% CI: 1.5-7.4, P=0.003). Of the patients who experienced excessive menstruation and prolonged periods, 72.2%(39/54) required intervention, with suspension of anticoagulants during menstruation as the main intervention (37.0%). The patients taking rivaroxaban were more likely to stop taking them during menstruation compared to those taking warfarin (OR=10.4, 95% CI: 1.2-87.2, P=0.019).

  Conclusions  Oral anticoagulation therapy significantly increased the incidence of AUB in women with thrombophilia and the risk of AUB associated with rivaroxaban was significantly higher than that with warfarin.