The thyroid gland produces two iodaminic acid hormones – triiodothyronine (T3) and thyroxin (T4), which are the most important regulators of metabolism, development and differentiation of all tissues of the body, especially thyroxin. Thyroid hormones have a certain effect on the protein-synthetic function of the liver, stimulating the formation of globulin that binds sex steroids. This is reflected in the balance of free (active) and related ovarian steroids (estrogens, androgens).
With a lack of T3 and T4, the secretion of thyroliberin increases, activating not only thyrotrophs, but also pituitary lactotrophs, which often causes hyperprolactinemia. In parallel, the secretion of LH and FSH decreases with inhibition of follicular and steroidogenesis in the ovaries.
The increase in the level of T3 and T4 is accompanied by a significant increase in the concentration of globulin that binds the sex hormones in the liver and leads to a decrease in the free estrogen fraction. Hypoestrogenism, in turn, leads to disruption of follicle maturation.
The adrenal glands. Normally, androgen production – androstenedione and testosterone – in the adrenal glands is the same as in the ovaries. DHEA and DHEA-C are formed in the adrenal glands, whereas in the ovaries these androgens are practically not synthesized. DHEA-S, secreted in the largest (compared with other adrenal androgens) quantities, has a relatively low androgenic activity and serves as a kind of reserve androgen form. Adrenal androgens along with androgens of ovarian origin are a substrate for extragonadal estrogen production.
Assessment of the reproductive system according to functional diagnostic tests
For many years in the gynecological practice, the so-called tests of functional diagnostics of the reproductive system state have been used. The value of these fairly simple studies has survived to the present. The most commonly used are basal temperature measurement, assessment of the “pupil” phenomenon and the state of cervical mucus (its crystallization, elongation), as well as the calculation of the karyopyknotic index (CPR,%) of vaginal epithelium.
The basal temperature test is based on the ability of progesterone (in increased concentration) to directly affect the thermoregulation center in the hypothalamus. Under the influence of progesterone, a transient hyperthermic reaction occurs during the 2nd (luteal) phase of the menstrual cycle.
The patient daily measures the temperature in the rectum in the morning, without getting out of bed. Results are displayed graphically. In a normal two-phase menstrual cycle, the basal temperature in the 1st (follicular) phase of the menstrual cycle does not exceed 37 ° C; in the 2nd (luteal) phase, a rectal temperature increases by 0.4–0.8 ° С compared to the initial value . On the day of menstruation or 1 day before its onset, the corpus luteum in the ovary regresses, the level of progesterone decreases, and therefore the basal temperature drops to baseline values.
A stable two-phase cycle (basal temperature should be measured over 2-3 menstrual cycles) indicates the occurrence of ovulation and the functional usefulness of the corpus luteum. The absence of temperature rise in the 2nd phase of the cycle indicates the absence of ovulation (anovulation); delay in lifting, its short duration (temperature rise by 2–7 days) or insufficient rise (by 0.2–0.3 ° C) – on the inferior function of the corpus luteum, i.e. progesterone deficiency. A false positive result (an increase in basal temperature in the absence of the corpus luteum) is possible with acute and chronic infections, with some changes in the central nervous system, accompanied by increased excitability.
The symptom of the “pupil” reflects the amount and condition of the mucous secretion in the cervical canal, which depends on the level of estrogen saturation of the organism. The phenomenon of the “pupil” is based on the expansion of the external pharynx of the cervical canal due to the accumulation of transparent vitreous mucus in it and is evaluated during examination of the cervix using vaginal mirrors. Depending on the severity of the symptom of “pupil” is estimated by three degrees: +,
Synthesis of cervical mucus during the 1st phase of the menstrual cycle increases and becomes maximal immediately before ovulation, which is associated with a progressive increase in estrogen levels in this period. On preulatory days, the dilated external opening of the cervical canal resembles the pupil (+++). In the 2nd phase of the menstrual cycle, the amount of estrogen decreases, progesterone is produced mainly in the ovaries, therefore the amount of mucus decreases (+), and before menstruation it is completely absent (-). The test can not be used for pathological changes in the cervix. Symptom of crystallization of cervical mucus (the phenomenon of “fern”) When drying is most pronounced during ovulation, then crystallization gradually decreases, and before menstruation is completely absent. The crystallization of air-dried mucus is also scored (from 1 to 3).
Symptom tension cervical mucus is directly proportional to the level of estrogen in the female body. To carry out the test with a forceps, the mucus is removed from the cervical canal, the branches of the instrument are slowly moved apart, determining the degree of tension (the distance at which the mucus “breaks”). The maximum stretching of the cervical mucus (up to 10-12 cm) occurs during the period of greatest estrogen concentration – in the middle of the menstrual cycle, which corresponds to ovulation.
Inflammatory processes in the genitals and hormonal imbalance can adversely affect mucus.
Cariopicnostic index (KPI). Under the influence of estrogens, cell proliferation of the basal layer of the stratified squamous epithelium of the vagina occurs, and therefore the number of keratinizing (peeling, dying) cells in the surface layer increases. The first stage of cell death is a change in their nucleus (karyopicnosis). KPI is the ratio of the number of cells with the pycnotic nucleus (that is, the dead ones) to the total number of epithelial cells in the smear, expressed as a percentage. At the beginning of the follicular phase of the menstrual cycle KPI is 20–40%, on preovulatory days it rises to 80–88%, which is associated with a progressive increase in the level of estrogen. In the luteal phase of the cycle, the level of estrogen decreases, therefore, the CRPD decreases to 20-25%. Thus, the quantitative ratios of cellular elements in smears of the mucous membrane of the vagina make it possible to judge the saturation of the body with estrogens.
At present, especially in the in vitro fertilization program (IVF), follicle maturation, ovulation and the formation of the corpus luteum are determined by dynamic ultrasound.