Anovulatory cycle is a monophasic menstrual cycle characterized by the absence of ovulation and the phase of development of the corpus luteum, while maintaining the regularity and rhythm of uterine bleeding. In gynecology, there are conditions accompanied by physiological anovulation (during periods of age-related rearrangements of the body), and a pathological anovulatory cycle in infertility. In the diagnosis of the anovulatory cycle, physiological tests, transvaginal ultrasound, and endometrial scraping are used. If an anovulatory cycle is detected, treatment is aimed at eliminating functional infertility and suppressing excessive endometrial proliferation. The prognosis is due to the reasons that caused the monophase cycle.
N97.0 Female infertility associated with the absence of ovulation
Anovulatory cycle is single-phase, since there is no sequential phase change characteristic of a normal menstrual cycle. Almost the entire this disease is occupied by the proliferation phase, which is replaced by desquamation and regeneration of the endometrium. At the same time, there is absolutely no secretory phase, usually occurring after ovulation due to the development of the corpus luteum. Unlike dysfunctional anovulatory uterine bleeding, this disease is characterized by cyclic menstrual-like bleeding.
In practically healthy women of reproductive age, disease is observed relatively rarely (1-3%) and may alternate with the ovulatory cycle. Anovulation can be caused, for example, by a change in climate when moving to another geographical region. The most frequent physiological causes of the anovulatory cycle are the processes of age–related changes in the female body – puberty and extinction of reproductive function (menopause). As a physiological process, anovulation in combination with amenorrhea is characteristic of pregnancy and postpartum lactation. In case of resumption of rhythmic bleeding in 40-50% of nursing women, the cycle has a single-phase anovulatory character.
Clinical gynecology considers the anovulatory cycle as a pathology requiring correction in infertility or uterine bleeding caused by a violation of folliculogenesis, lack of ovulation and luteal phase. The causes of the pathological anovulatory cycle, as a rule, are:
- Disorders of hypothalamic-pituitary regulation. They are manifested by insufficient production of FSH, leading to immaturity of the follicle and its inability to ovulate; insufficient LH; a change in the ratio of sex hormones, sometimes – excessive production of prolactin by the pituitary gland.
- Dysfunction of the ovaries and other glands. Disease may be associated with inflammation of the ovaries or appendages (adnexitis), a violation of the enzyme transformation of sex steroids in the ovaries, functional disorders in the thyroid gland or the cortical layer of the adrenal glands, disorders of sexual development.
- Other causes: infections and intoxication, neuropsychiatric disorders, vitamin deficiency, other alimentary disorders, congenital defects of the reproductive system, genetic pathology.
During the anovulatory cycle in the ovaries, periods of growth and reverse development of the follicle may vary in nature and duration. Short-term rhythmic persistence of a mature follicle is accompanied by hyperestrogenism; atresia of an unripe follicle is accompanied by relative monotonous hyperestrogenism. The most typical for the anovulatory cycle is an excess of the action of estrogens, not replaced by the influence of the progestogenic hormone progesterone. In some cases, the anovulatory cycle proceeds with hypoestrogenism. Depending on the level of estrogenic influence, endometrial changes of various types develop – from hypoplasia to excessive proliferation – hyperplasia and polyposis.
The development of menstrual-like bleeding during the anovulatory cycle is usually due to a decline in hormonal influence caused by follicle atresia. In the functional layer of the endometrium, the phenomena of transudation, hemorrhages, and areas of necrosis develop. The surface layers of the endometrium partially disintegrate, which is accompanied by bleeding. In the absence of endometrial rejection, bleeding develops due to diapedesis of erythrocytes through the walls of blood vessels. Sometimes there is no decline in hyperestrogenism, and the excretion of estrogens in the urine remains relatively stable throughout the anovulatory cycle (from 13 to 30 mcg / day).
At puberty, when menstrual function is formed, the anovulatory cycle is due to the lack of the necessary level of luteinizing and luteotropic hormones, the synthesis of which reaches a peak by the age of 15-16. Similar changes, but in reverse order, develop with the extinction of reproductive function: there is a violation of cyclic secretion and an increase in gonadotropic effect. The alternation of ovulatory and anovulatory cycles in the menopausal period is replaced by a change in the duration of the cycle and the nature of menstruation.
Clinically, disease can manifest itself in different ways. Menstrual-like bleeding that occurs during an anovulatory cycle may not differ from normal menstruation in regularity and the amount of blood lost.
With hyperesterogeny, bleeding is accompanied by prolonged and copious discharge of blood by the type of menorrhagia. In this case, a two-handed examination reveals an enlarged uterus of a dense consistency with a softened neck and a slightly open inner pharynx. Heavy bleeding eventually leads to the development of anemia.
Hypoestrogenia, on the contrary, is characterized by shortened and meager menstrual bleeding. During a vaginal examination, a reduced uterus is determined, having a long conical neck, a closed internal pharynx, and a narrow vagina. The anovulatory cycle in women of reproductive age is accompanied by the impossibility of pregnancy – hormonal infertility, in connection with which patients usually turn to a gynecologist.
The simplest method of differentiation of ovulatory and anovulatory cycles is the determination of rectal (basal) temperature (BT). The normal ovulatory cycle is characterized by an increase in BT in the progesterone phase. With an anovulatory cycle, a single-phase temperature is determined.
- Functional tests. A pronounced estrogenic effect in the case of an anovulatory cycle is detected using functional tests (a positive fern phenomenon and a “pupil” symptom throughout the cycle), colpocytological data.
- Ultrasound of the pelvic organs. A sign of an anovulatory menstrual cycle with dynamic ultrasound of the ovaries is the absence of a dominant follicle.
- RDV. The decisive criterion for determining the anovulatory cycle is the diagnostic curettage of the uterine cavity on the eve of menstruation with a histological examination of the scraping. The absence of secretory changes in the endometrium in the scraping confirms the presence of an anovulatory cycle.
- Hormonal studies. To clarify the etiological prerequisites of the anovulatory cycle, a study of hormones of the hypothalamic-pituitary system, thyroid gland, adrenal cortex is carried out. Taking into account the possible alternation of anovulatory and ovulatory cycles, dynamic monitoring is carried out for the final diagnosis within six months.
Treatment of anovulatory cycle
Since a persistent anovulation cycle is accompanied by infertility and pronounced proliferative changes in the endometrium, the main task of treatment is to stimulate ovulation and suppress excessive proliferation. An anovulatory cycle is treated by a gynecologist-endocrinologist.
Hormonal therapy of the anovulatory cycle is carried out in intermittent cycles, depending on the degree of estrogenic saturation. For step-by-step stimulation of the correct menstrual cycle after preliminary scraping of the endometrium, gonadotropic drugs are prescribed for 3-6 months from day 11 to 14. 6-8 days before menstruation, intramuscular injections of progestogens are connected. With an anovulatory cycle occurring with hyperestrogenism and excessive proliferation, synthetic progestins are indicated for several cycles (from day 5 to day 25 of the cycle).
In case of ovarian insufficiency and hypoestrogenism, estrogenic drugs are used in small doses that stimulate the transformation of the uterine mucosa, ovarian function, growth and development of the follicle. If the cause of the anovulatory cycle is chronically occurring inflammation of the appendages, complex treatment of adnexitis is carried out, vitamin C is prescribed, which is involved in the synthesis of steroids and contributes to the restoration of ovulation.
In order to induce ovulation during the anovulatory cycle, indirect electrical stimulation of the hypothalamic-pituitary region is prescribed by endonasal electrophoresis, electrical stimulation of the cervix, etc. Hormonal stimulation of ovulation is performed. In hyperprolactinemia, dopamine receptor agonists are prescribed. Treatment of physiological anovulation during periods of menstruation, lactation, menopause is not required.
Prognosis and prevention
With properly designed and conducted treatment of the anovulatory cycle, pregnancy occurs in 30-40% of women. If it is not possible to achieve pregnancy, women are recommended to resort to assisted reproductive technologies under the IVF program. If the patient does not have her own mature eggs, artificial insemination is carried out with a donor egg, after which the embryo is transplanted into the uterine cavity. It is possible to use a donor embryo.
To prevent the disease, it is necessary to pay increased attention to the health of adolescent girls, proper nutrition, rational activity and rest regimen, timely treatment of genital and extragenital pathology; prevention of infections, toxic effects at work.