In the normal ovarian functioning among women, certain hormones are released by the pituitary gland during the menstrual cycle. These hormones help in causing a small number of egg-containing follicles. These follicles start their maturing journey in the ovaries.
Normally, only one follicle that is filled with fluid reaches the maturity stage every month. Upon reaching the maturity, the follicle gets ripped open and releases the egg. The egg thereafter enters one of the Fallopian tubes awaiting a sperm to penetrate fertilize it. Finally, the entire process results in a pregnancy. Premature ovarian failure happens because of the following reasons:
- Follicle Draining
- Follicle Dysfunction
The causes of follicle draining are:
Some genetic disorders are linked to Premature Ovarian failure. One such defect is Turner Syndrome. The name of this condition has come to it as it was first described by Henry Tuner in 1938 and is also known as Ullrich–Turner syndrome or gonadal dysgenesis or 45X. Most of the females have 46 chromosomes, but women having this condition have only 45.
That means one of the sex chromosomes is partly or completely missing. The Tuner Syndrome may place women in several medical and developmental problems. They are:
- Short and webbed neck
- Short height
- Swollen hands and feet
- Undeveloped breasts
- Heart Diseases
- Low Thyroid hormone
- Spatial Visualization
Turner syndrome may be diagnosed before birth (prenatal), during infancy or in early childhood. Occasionally, the diagnosis is delayed until the teen or young adult years in those who have mild signs and symptoms of Turner syndrome.
Nearly all girls and women with Turner syndrome need ongoing medical care from a variety of specialists. Regular checkups and appropriate care can help most girls and women lead relatively healthy, independent lives.
Anticancer drugs and therapies harm dividing cells and this effect is more of the Granulosa and Theca cells of the ovary than the non-dividing oocytes. And, this effect on the ovarian function may greatly vary from one woman to another. Well, some women may experience no harm to the ovarian function, others may experience hypogonadism permanently.
Normally, the ovaries of women, who underwent chemotherapy or radiation therapy, will have normal to slightly reduced amount of primordial follicles. On the other hand, they may experience larger loss in the numbers of larger maturing follicles. These point out larger harm on follicular growth rather than on oocytes. The clinical observations and the microscopic studies of these ovarian cells confirm that several women, especially under the age of 40, develop amenorrhea during chemotherapy or radiation therapy, more often having high serum gonadotropin (Gn-RH) concentrations.
Once the therapies are discontinued, in some of the cases, menstrual function and fertility may return after several months of discontinuity. To sum it up, chemo and radiation therapies are the most common reasons of damaging genetic elements of cells and, thus, toxin-induced ovarian failure. Besides, other toxins such as tobacco chewing, cigarette/beedi smoking, excessive use of alcohol, chemicals, viruses and pesticides may also add to and accelerate premature ovarian failure.
Follicle dysfunction may be the result of:
An immune system response to ovarian tissue (autoimmune disease)
The immune system generally attacks only infections and other substances that are considered to be invaders from outside the body or cancerous tissues made within the body. But, when the immune system gets confused, it starts attacking healthy body cells. In the context of premature ovarian failure, your immune system might generate antibodies in opposition to your own ovarian tissue, affecting the follicles that contain egg and harming the egg.
What prompts the immune response is not known, but there is a possibility of virus exposure. In a review, Dr. Aschkenazi and his colleagues have argued that sex hormones, particularly the estrogens, play a vital role in the doings of immune cells. Additionally, deficiency in estrogen levels because of hormonal imbalances may lead to failure of estrogen to regulate the immune system correctly. Hormonal therapy is recommended in autoimmune disease cases.
If you happen to experience premature ovarian failure because of follicular dysfunction and your investigations are found to be negative towards you having an autoimmune disease, more tests are done. But an exact cause of your premature ovarian failure remains unclear.
Researchers believe that you may experience early ovarian failure after: