Heavy menstrual bleeding in women on oral anticoagulants

Background: Although heavy menstrual bleeding (HMB) is a known complication of anticoagulant therapy, rates of HMB in users of the direct oral anticoagulants (OACs) apixaban and rivaroxaban are largely unknown. Methods: We performed a retrospective cohort study of menstruating women prescribed rivaroxaban, apixaban and warfarin over a six-year period (2012-2018). The primary outcome was HMB requiring medical or surgical intervention. We used descriptive statistics and logistic regression to evaluate associations between OAC type, age, history of HMB, and the primary outcome. Results: We identified 195 women of reproductive-age with a new therapeutic OAC prescription (62 on rivaroxaban, 54 on apixaban, 79 on warfarin). A minority (26/195, 13.3%) had a documented history of HMB, including 9 rivaroxaban users, 7 apixaban users and 10 warfarin users but most women (117/195, 60%) had no menstrual history documented. One third of subjects (64/195) required treatment for HMB within 6 months of starting OAC therapy. After controlling for a history of HMB, rivaroxaban users were 1.4 times more likely to require treatment as compared to users of other OACs. Discussion: We found an association between rates of HMB necessitating medical or surgical intervention and rivaroxaban use. We also found that the majority of women did not have a documented menstrual history, suggesting that many providers do not inquire about menstrual bleeding when starting OAC therapy. Menstruating women, particularly those with a history of HMB, may be at increased risk for HMB necessitating medical treatment depending on the type of OAC used.