The menstrual bleeding or menstrual flow is said to be reduced if there is a significant and consistent reduction in the volume and duration of the menstrual flow of a woman with a regular menstrual cycle. Because a normal menstrual flow is expected to last between 2 to 8 days, any menstrual flow that last less than 2 days is also regarded as a reduced menstrual flow. Occasionally, it may be so severe that it may present as the presence of mere spotting of blood from the vagina, each time the menses is expected, usually lasting less than a day. This is medically referred to as “scanty vaginal bleeding”. In exreme cases, a total absence of a regular menstrual flow (i.e. secondary ameorrhea), may be noted, associated with varying degree of cyclical or recurrent lower abdominal pain (i.e secondary dysmenorrhea).
The menstrual flow or bleeding is formed as a result of the cyclical shedding of the superficial layer of the endometrium, which then passes through the lower part of the uterus, the cervix and the vagina to become what is now known as the menstruum. Any damage or injury to any part of these structures that either form the menstruum or allow passage of the menstruum will result in the formation of scar tissues that may occlude or obstruct both the formation and the outflow of the menstrual flow. For example, the formation of scar tissues in the endometrium of the uterus, may prevent the normal shedding of the endometrium resulting in reduced menstrual flow, while the formation of scar tissues in the lower part of the uterus, the cervix and or the vagina may result in partial or total obstruction of the normal flow of the menstruum, resulting in reduced or complete absence of menstruation. The common causes of regular but reduced or scanty menstrual flow are:
1. Manual removal of retained placenta during delivery
4. Cone biopsy
5. D and C
7. Repair of cervical laceration or tears at birth
8. Insertion of corrosive agents into the vagina and or the cervix