Excessive and heavy menstrual bleeding is generally associated with fibroids or tumors in the uterus. However, such erratic bleeding can also occur in the absence of any abnormality in the uterus. This is known as dysfunctional uterine bleeding. Majority of dysfunctional uterine bleeding cases are anovulatory bleeding.
Causes of Anovulatory Bleeding
Approximately two weeks before menstruation, the endometrium or the inner lining of the uterus, becomes thick. The arteries, glands and the epithelial cells become large. Development of endometrium is assisted by the rise in estrogen secretion. During this time, ovulation takes place. If the egg released in the ovary fails to fertilize within two weeks, endometrium sheds, resulting in menstrual bleeding. After ovulation, further growth of the endometrium is arrested by increase in progesterone secretion, which counters the action of estrogen.
If due to hormonal misbalance, ovulation fails to occur, progesterone is not secreted to halt the action of estrogen. The growth of endometrium therefore continues unhindered. This condition, known as anovulation, makes the endometrium thicker. It lacks structure and therefore sheds off suddenly, causing heavy bleeding.
Anovulatory bleeding largely occurs for two or three years following the first menstrual cycle. As a woman approaches menopause, anovulatory periods occur. Anovulatory cycle also takes place in women undergoing estrogen therapy. Intake of oral contraceptives can also be responsible for anovulatory bleeding. Stress and certain ailments, such as polycystic ovary syndrome, hypothalamic dysfunction, luteal phase defects, hyperprolactinemia or ovary, pituitary gland and adrenal gland tumors might be responsible for anovulation.
Women experiencing anovulatory periods for a long time suffer from anemia. Infertility and incidence of endometrial cancer is high among them. Anovulation occurs mostly during adolescence and menopause. It rarely occurs during the childbearing years. If it occurs during the childbearing years, the risk of failure in conception arises. Fertility drugs might help in overcoming this condition. In older women, hormone therapy or removal of the endometrium, known as endometrial ablation, might help in overcoming the problem.