Measured menstrual blood loss in women with a bleeding disorder or using oral anticoagulant therapy.

Bleeding disorders in women are associated with a high incidence of menorrhagia, but few objective data exist. Whether oral anticoagulant therapy in women is also associated with a higher incidence of menorrhagia is unknown. We measured menstrual blood loss in six women with various congenital or acquired bleeding disorders and in 11 women treated with oral anticoagulant therapy. Mean menstrual blood loss in women with a bleeding disorder was 219 ml (range, 60 to 568 ml); five women had menorrhagia. In women treated with oral anticoagulant therapy, mean menstrual blood loss was 98 ml (range, 9 to 239 ml), and five women had menorrhagia. Of the six women with normal menstrual blood losses, two had losses in the high normal range (60 to 80 ml). No correlation existed between anticoagulant state and menstrual blood loss. The data support the close association between bleeding disorders and menorrhagia and suggest that oral anticoagulants increase menstrual blood loss.