Pathogenetic links in the process of ovulation are the above causes that upset the hormonal balance, which results in a violation of the first phase of the ovulatory cycle at any stage - maturation or release of the egg from the dominant follicle.
Polycystic ovary syndrome is the main role in the pathogenesis of anovulation. In this case, the hypothalamic-pituitary and ovarian ovulatory mechanisms are violated. In the pathogenesis of sclerokinosis, as its complications, hyperproduction of foliotropin is also considered, which contributes to abnormal ovarian function and the formation of dense cysts instead of follicles, which makes ovulation impossible. Luteotropin deficiency is also considered.
Another hypothesis in the first place displays the hyperactivity of the adrenal cortex, the violation of the secretion of steroids and estrogen deficiency, which upsets the process of maturation of the follicles, leads to the development of androgenital syndrome, anovulation and amenorrhea.
For the period of formation of fertility, anovulation due to insufficient level of luteotropin is typical, its production grows and reaches peak values by 15-16 years. The reverse process - a decrease in the synthesis of hormones necessary for ovulation occurs with the extinction of ability to childbearing (menopause).
In hypothalamic-pituitary disorders with an excess of prolactin, anovulation is a consequence of the inhibitory effect of it several times the amount normal to the ovaries, the pituitary function of producing luteotropin (does not reach the peak required for ovulation), and hypothalamic-synthesis of gonadotropin-releasing hormone.
Neoplasms of hypothalamic localization and other neuroprocesses in the hypothalamus, starvation, a sharp decrease in body weight can cause a decrease and even completely stop the production of gonadotropin-releasing hormones and with a normal prolactin content.
The consequence of surgical intervention for pituitary adenoma, as well as - radiation therapy may be the absence of ovulation due to a sharp decrease in the level of gonadotropic hormones. This is also promoted by excessive secretion of androgens.
Anovulation can be accompanied by a lack of menstruation or uterine bleeding, however, women often have a single-phase (anovulatory) menstrual cycle that ends with menstrual bleeding. Failure affects the ovulatory phase, and the secretory and development of the yellow body does not occur at all. Virtually the entire single-phase cycle is the proliferation of endometrial cells, followed by their necrosis and rejection. During its course in the ovaries completely different in nature and duration of the stages of development and regression of the follicle.
For anovulation, hyperestrogenia is more characteristic throughout the entire cycle, without changing for progesterone effect in the second phase of the normal cycle. Although sometimes the level of estrogen is reduced, which affects the nature of changes in the endometrium - from hypo- to hyperplastic, accompanied by proliferation of glandular polyps.
Bleeding at the end of the anovulatory cycle is explained by the regression of immature follicles, which, as a rule, is accompanied by a decrease in the level of estrogens. The functional layer of the endometrium is subjected to destructive changes - vascular permeability increases, effusions, hematomas, necrosis of tissues appear. The surface layer of the endometrium is rejected, causing bleeding. If this does not occur, bleeding diapedesis occurs as a result of migration of red blood cells through the shells of blood vessels.
Every third case of female infertility, according to statistics, is caused by the lack of ovulation. In turn, the leading cause of this dysfunction, gynecologists call polycystic ovary, which is diagnosed in no more than one in ten of the fair sex of childbearing age. In this case, the external signs of polycystosis are detected by ultrasonic examination of ovaries of women of fertile age twice as often. But the clinical picture, corresponding to the syndrome of polycystic ovaries, is not found at all.
Sclerokistoz ovaries is diagnosed in three to five percent of gynecological pathologies, one third of cases is accompanied by persistent infertility.
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