Bleeding from the vagina at times other than during a menstrual period, or bleeding during a period that is heavier than usual. In women of reproductive age, causes of abnormal vaginal bleeding can include the use of birth control pills; hormonal imbalances; infections of the reproductive system, including sexually transmitted diseases; an ectopic pregnancy; and miscarriage. Abnormal bleeding can also result from scars, tumors, fibroids, or other abnormal tissue in the uterus or cervix; or by cysts on the ovaries.