There are many causes of anovulation ,for example ovarian failure which is of genetic etiology. In this condition ,since there is no follicular tissue, the ovary is unable to respond to any FSH stimulation, resulting in a very high level of FSH in these woman (Similar to postmenopausal woman and in men with testicular failure).
A failure at the hypothalamic – pituitary axis is also a cause of anovulation.Thyroid problems, Hyperprolactinemia, obesity , Polycystic ovarian disease are other important causes.
Prolactin is a hormone produced by the pituatory gland. Normal levels of prolactin are required for the normal luteal phase of ovulation.Normal levels of Prolactin vary between 4-25 nanograms per ml of blood.
Hyperprolactinemia i.e. increased prolactin levels causes an inadequate luteal phase. This later progresses to anovulation and then to lack of menses i.e. amenorrhoea.
Along with menstrual disturbances like scanty menses, delayed menses, and anovulation, hyperprolactinemia also causes watery or milky discharge from the breasts. This is called as galactorrhoea.
Both excess and low levels of thyroid hormone alter the metabolic clearance and the conversion rates of the steroid hormone. Also a subtle presence of low levels of thyroid gland causes elevated prolactin levels. As a result of all these factors, ovulation and hence the menstrual cycle of the woman gets affected.
Anovulation is associated with many menstrual irregularities like delayed menses, heavy prolonged menstrual flow, shorter cycle length, very scanty menses and absent menses.It is also a very important cause of infertility.
These woman are generally obese with excess facial hair on their face (Hirsutism), loss of scalp hair and acne.Persistent anovulation is associated with endometrial cancer, perhaps with breast cancer, increased risk of cardiovascular disease and diabetes mellitus at a later stage in life.
As anovulation is associated with all these problems, it should be treated in its early stages and should not be left unattended.
The treatment of anovulation would depend on the cause and the clinical presentation. A young woman with anovulation who is not interested in conceiving is given birth control pills and a woman who wishes to conceive is given ovulation inducing tablets/hormonal injections.