Lecture 16: modern understanding of the neuroendocrine control of the menstrual cycle


A common question: can I get pregnant if unprotected sexual intercourse occurs on a certain day of the menstrual cycle - many women care about it in various medical forums. To answer these questions yourself, it is enough to understand the mechanism of the likelihood of pregnancy depending on the moment of the menstrual cycle, with which we will introduce you.

Please note that in this article we proceed from the following premise: sexual intercourse was not protected, therefore, a woman may become pregnant. We did not take into account such important factors for conception as a partner's reproductive ability, gynecological problems with a partner, compatibility in a pair. Such individual characteristics of sexual intercourse can certainly play a role in the onset of pregnancy.

Of course, the initial question about the possibility of becoming pregnant on a certain day of the cycle women ask for two reasons: some want to increase the chances of conception, the second - on the contrary.

Many are familiar with the calendar method: its meaning is that with a “standard” menstrual cycle lasting 28 days, the probability of becoming pregnant is highest on days 10-17 of the cycle, during the so-called “fertile window”. Accordingly, the time from the beginning of menstruation to the 10th day of the cycle, as well as from the 17th to the 28th, is “safe”, that is, the probability of becoming pregnant is minimal. Unfortunately, this method, despite popular popularity, cannot be considered reliable. Doctors ascertain: it is not necessary to rely on such calculations, because the female body is rather complicated. Recent studies in obstetrics and gynecology have shown that the most regular menstrual cycles are observed in women aged 25 to 35 years, but they also have sudden, or sporadic, ovulations: accordingly, they can become pregnant on any day of the cycle. According to specialists, only a third of women can rely on the calendar method.

Of course, there is a connection between the possibility of conception and the regularity of the menstrual cycle: first of all, it concerns the health of the female body and its readiness for the onset of pregnancy. During the establishment (adolescence) and completion (maturity) of the menstrual cycles, it is almost impossible to calculate the possibility of pregnancy, because ovulations are quite irregular. But, according to doctors, for most women, the probability of conception is highest approximately after the end of menstruation and two weeks later. Naturally, these are only approximate calculations that should not be guided as a means of protection. In addition, the condition of a woman affects the ability to become pregnant: illness, fatigue, changing the situation and stress reduce it.

At the beginning of the twentieth century, a German specialist conducted a study, the results of which convincingly proved the inconsistency of the calendar method: according to his observations, 25 women had become pregnant as a result of one sexual intercourse in the interval from 2 to 30 days of the cycle.

The probability of conception is significantly reduced, provided that:

  • Emergency contraception followed sexual intercourse, which was not protected.
  • Started a new menstrual cycle (monthly)
  • Pregnancy test remains negative a few weeks after unprotected intercourse.
Accordingly, the possibility of becoming pregnant is much higher if the woman has a menstrual delay.

Ability to get pregnant with a regular menstrual cycle lasting 28 days

The most "dangerous" or "happy" days for conceiving in such women are 10-17 days of the menstrual cycle. Accordingly, the probability of pregnancy is significantly lower in the 6-9 and 18-21 days of the cycle (about 10%). And to get pregnant in 1-5 and 22-28 days of a regular menstrual cycle it is possible units (1-5%).

Chance to get pregnant with irregular menstrual cycle

Unfortunately, with an irregular cycle it is difficult to predict the moment of ovulation, therefore, it becomes almost impossible to draw conclusions about the probability or improbability of conception.

The probability of becoming pregnant during lactational amenorrhea (breastfeeding after childbirth and the absence of menstruation)

Nature specifically developed the mechanism of “postpartum contraception”: while the woman is breastfeeding the baby, the body does not allow her to become pregnant again. Unfortunately, this method does not give a 100% guarantee that conception will not occur. The fact is that the absence of menstruation and regular feeding on demand does not guarantee the onset of ovulation (which can occur before the first postpartum menstruation), so some women become pregnant in the first months after childbirth. Of course, if a young mother breastfeeds, and the menstrual cycle has already resumed, then she could theoretically become pregnant with any unprotected intercourse.

The probability of becoming pregnant in the case of primary amenorrhea (never had menstruation)

In this case, the probability of pregnancy is quite small. However, primary amenorrhea is not synonymous with infertility, as some believe. Doctors successfully correct gynecological problems that "prevent" the body from starting the menstrual cycle, after which the chances of getting pregnant become much higher.

The probability of becoming pregnant in case of secondary amenorrhea (menstrual disorders, when menstruation was, but they have not been over 3 months)

In this case, the chances of pregnancy are low, but even here medicine can come to the rescue: it is enough to consult with a competent doctor who will draw up an individual treatment regimen in order to increase the likelihood of conception.

What conclusions can be made?

If you do not want to become pregnant now, then you should not rely on the calendar method as a way of protection, even if you have a regular menstrual cycle. Reliably protect you from unwanted pregnancy contraceptive means (condoms, birth control pills). In addition, it must be remembered that unprotected sexual intercourse with a random partner is fraught with STDs, including AIDS and herpes.

Those who dream of an early pregnancy, it is also better not to look at the calendar: doctors recommend having a regular sex life (at least 3 times a week), regardless of the day of the menstrual cycle. So the probability of conception becomes really high.

Features of the menstrual cycle and its relationship with pregnancy

The menstrual cycle is one of the main indicators of women's health. In a certain period of his ovulation occurs, the possibility of conception. Accordingly, the menstrual cycle and pregnancy are closely interrelated. Therefore, a woman planning to become a mother needs to know at what periods the chances of conception are greater and when fertilization is impossible.

Causes and signs of menstruation during pregnancy

Every menstrual cycle normally begins with the appearance of bloody discharge from the vagina. This is a natural physiological process that occurs monthly in the body of a non-pregnant woman.

Sometimes the appearance of bleeding is noted in the case of successful fertilization. There may be several reasons for this:

  • Conception in the last 24 hours of the cycle (the egg has not yet managed to implant),
  • hormonal fluctuations. A sharp decrease in the concentration of hormones is often provoked by inflammation in the reproductive system and endocrine disorders,
  • the release of the ovum from the follicle or the rejection of the egg.

Among the symptoms of menstruation during this period are the following:

  • an increase in breast size
  • abdominal pains extending to the sacrum and lower back,
  • depressed state
  • trouble sleeping
  • bloody daub.

The emergence of regul in early pregnancy is quite possible. Nevertheless, pain and bleeding (even scanty) should be a reason to visit a doctor. Often, such changes are a serious threat and signal the risk of miscarriage.

The days in which it is impossible to get pregnant

The countdown starts from the first day of menstruation, but the duration of the cycle is different for all the fair sex. For this reason, the exact dates of safe days after the month, in which conception is impossible, cannot be named. In addition, there are no absolutely safe periods as such. Just at certain intervals, fertilization becomes unlikely.

After ovulation (this moment falls in the middle of the cycle) the most favorable time for conception comes. Conditionally safe is considered to be a couple of days before the arrival of the regulation and two days after their completion. It should be borne in mind that during these periods fertilization is impossible only if the cycle is regular and there are no failures in it over the long term.

If conception did occur, then there is no cyclic change during pregnancy.

What days can you get pregnant

To calculate when a woman can conceive, you need to understand how a woman has a reproductive system. With the appearance of regul in the appendages, the growth of follicles begins. These are peculiar sacs within which the process of egg maturation takes place.

In the middle of the next period of cyclic changes, this follicle is revealed, the fetal egg comes out of it. It begins to move towards the cavity of the reproductive organ through the fallopian tubes. The probability of pregnancy reaches a maximum at this moment. Thus, with a cycle of 28 days, conception is likely to occur on the 14th or 15th day.

The chances of successful fertilization also remain on other days, close to the time of ovulation. This is due to the fact that the egg cell is viable for 1-2 days. In addition, sperm after penetration into the female body often remain active up to one week.

Before menstruation

The release of the egg from the follicle occurs in the middle of the cycle. Before the regulation of the egg, the fertilized egg is already dying, but if the process of ovulation starts much later or repeats itself, conception is still possible. True, this can prevent a change in the level of hormones. The body at this point is already configured for a new cycle.

If a woman has an irregular intimate life, then the chances of successful fertilization are quite large. In such a situation, conception is possible after each act of love. The body can respond to intimacy by extraordinary ovulation. Sperm substances are also capable of provoking this process. If a woman has an active sex life, then the probability of fertilization during this period is substantially less.

Immediately after menstruation

Most women think it is impossible to get pregnant after menstruation. Doctors have a slightly different opinion. They claim that conception can occur at any time.

After the spermatozoa are inside the vagina, they begin to move towards the egg cell and remain viable for up to one week. If the cycle is short, and the regulations are observed over a long period, then the chances of conception these days are quite large. Intimacy can occur on the most favorable dates.

There are several reasons why pregnancy occurs immediately after the end of menstruation:

  • viable sperm,
  • the maturation in the ovaries of several fetal eggs during a cycle,
  • shift the timing of ovulation. This can be provoked by fluctuations in the level of sex hormones and an unspecified, irregular cycle of menstruation.

During menstruation

Intimacy in the regulatory period is not recommended. This is due to the fact that the cervix is ​​open at this moment, which means that pathogenic organisms can easily penetrate inside. Conception during menstruation is unlikely because an unfavorable environment is created in the reproductive system to promote sperm and attach the egg. Prevent this process abundant discharge.

Fertilization on critical days occurs for the following reasons:

  • long regulations Until the moment when the ovum leaves the ovary, there may be less than a week,
  • cycle failure,
  • wrong count of safe days. Accurately find out that the period of ovulation has come is possible by measuring the basal temperature. With an irregular cycle, this method is uninformative.

Recommendations for the normalization of the menstrual cycle

Violation of the cycle - a signal that there are problems with the health of women. It is best to go to the gynecologist right away. The doctor will conduct a comprehensive diagnosis and select the appropriate treatment tactics.

There are a number of recommendations to help normalize the cycle. If you stick to them, it is possible that the next menstruation will come in due time:

  1. Eat right. This will help restore hormones. In the diet should be vegetables, cereals, dairy products.
  2. Temporarily refuse to take oral contraceptives. Drugs in this group alter hormone levels.
  3. Properly organize the daily routine. There should be enough time for rest.
  4. Moderate exercise.
  5. In the presence of pathologies occurring in a chronic form, to conduct appropriate treatment.
  6. Avoid stressful situations that also adversely affect the hormonal background.

It is possible to calculate days favorable for conception with maximum accuracy only if there are no irregularities in the menstrual cycle. Even minor disruptions become an obstacle to determining the period in which successful fertilization can occur.

Regulation of the menstrual cycle

The reproductive system is organized on a hierarchical basis. There are 5 levels in it, each of which is regulated by overlying structures by the feedback mechanism:

1) the cerebral cortex

2) subcortical centers, located mainly in the hypothalamus,

3) the appendage of the brain - the pituitary gland,

4) the sex glands - the ovaries,

5) peripheral organs (fallopian tubes, uterus and vagina, mammary glands).

Peripheral organs are the so-called target organs, since due to the presence of specific hormonal receptors in them, they most clearly respond to the action of sex hormones produced in the ovaries during the menstrual cycle. Hormones interact with cytosolic receptors, stimulating the synthesis of ribonucleoproteins (c-AMP), promote reproduction or inhibition of cell growth.

Cyclic functional changes occurring in a woman’s body are conventionally grouped into several groups:

changes in the hypothalamus - pituitary, ovaries (ovarian cycle),

uterus and primarily in its mucous membrane (uterine cycle).

Along with this, cyclic shifts occur throughout the woman’s body, known as the menstrual period. They are expressed in periodic changes in the activity of the central nervous system, metabolic processes, functions of the cardiovascular system, thermoregulation, etc.

First level. Cortex.

Localization of the center regulating the function of the reproductive system has not been established in the cerebral cortex. However, through the cerebral cortex in humans, in contrast to animals, the external environment is affected by the underlying divisions. Regulation is carried out by means of amyloid nuclei (located in the thickness of the large hemispheres) and the limbic system. In the experiment, electrical stimulation of the amyloidal nucleus causes ovulation. In stressful situations with climate change, the rhythm of work there is a violation of ovulation.

Cerebral structures located in the cerebral cortex perceive impulses from the external environment and transmit them via neurotransmitters to the neurosecretory nuclei of the hypothalamus. Neurotransmitters include dopamine, norepinephrine, serotonin, indole and a new class of morphine-like opioid neuropeptides - endorphins, enkephalins, donorphins. Function - regulate the gonadotropic function of the pituitary gland. Endorphins inhibit the secretion of LH and reduce the synthesis of dopamine. Naloxone - an antagonist of endorphins - leads to a sharp increase in the secretion of GT-RG. The effect of opioids is carried out by changing the content of dopamine.

The second level is the pituitary zone of the hypothalamus

The hypothalamus is a division of the diencephalon and, with the help of a number of nerve conductors (axons), is connected to various parts of the brain, due to which central activity is regulated. In addition, the hypothalamus contains receptors for all peripheral hormones, including ovarian (estrogen and progesterone). Consequently, the hypothalamus is a kind of transfer point, in which complex interactions take place between impulses entering the body from the environment through the central nervous system, on the one hand, and the effects of hormones from peripheral endocrine glands, on the other.

In the hypothalamus nerve centers are located, providing the regulation of menstrual function in women.Under the control of the hypothalamus is the activity of the appendage of the brain - the pituitary gland, in the anterior lobe of which gonadotropic hormones are secreted, affecting the function of the ovaries, as well as other tropic hormones that regulate the activity of a number of peripheral endocrine glands (adrenal cortex and thyroid gland).

The system of the hypothalamus-pituitary is combined by anatomical and functional connections and is an integral complex that plays an important role in the regulation of the menstrual cycle.

The controlling effect of the hypothalamus on the anterior lobe of the adenohypophysis is carried out by secreting neurohormones, which are low molecular weight polypeptides.

Neurohormones that stimulate the release of the tropic hormones of the pituitary gland are called releasing factors (from release to release), or liberin. Along with this, there are also neurohormones that inhibit the release of tropic neurohormones - statins.

The secretion of RG-LH is genetically programmed and occurs in a specific pulsating mode with a frequency of 1 time per hour. This rhythm is called the tsirkharalny (clock).

The cirrhoral rhythm was confirmed by direct measurement of LH in the portal system of the pituitary stalk and jugular vein in women with normal function. These studies allowed to substantiate the hypothesis about the launching role of RG-LH in the function of the reproductive system.

The hypothalamus produces seven releasing factors leading to the release of the corresponding tropic hormones in the anterior pituitary gland:

somatotropic releasing factor (SRF), or somatoliberin,

adrenocorticotropic releasing factor (ACTH-RF), or corticoliberin,

thyrotropic releasing factor (TRF), or thyroliberin,

follicle-stimulating releasing factor (FSH-RF), or follyberin,

luteinizing releasing factor (LRF), or luliberin,

prolactin releasing releasing factor (PRF), or prolactoliberin.

Of the listed releasing factors, the last three (FSH-RF, L-RF and P-RF) are directly related to the implementation of the menstrual function. With their help, the release of three corresponding hormones, gonadotropins, in the adenohypophysis, as they have an effect on the gonads, the sex glands.

Factors that inhibit the release of tropic hormones in the adenohypophysis, statins, have so far found only two:

somatotropininhibitory factor (CIF), or somatostatin,

prolactin inhibiting factor (MIF), or prolactostatin, which is directly related to the regulation of menstrual function.

Hypothalamic neurohormones (liberins and statins) enter the pituitary gland through its leg and portal vessels. A feature of this system is the possibility of blood flow in it in both directions, due to which a feedback mechanism is implemented.

The circhoral regimen of excretion of WG-LH is formed at puberty and is an indicator of the maturity of the hypothalamic neurostructures. Estradiol has a definite role in the regulation of the release of WG-LH. In the preovulatory period, against the background of the maximum level of estradiol in the blood, the magnitude of the release of WG-LH is much higher in the early foliculine and luteal phase. It is proven that thyroliberin stimulates prolactin release. Dopamine inhibits prolactin secretion.

The third level is the anterior pituitary (FSH LH, prolactin)

The pituitary gland is the most complex in structure and functionally endocrine gland, consisting of an adenohypophysis (anterior lobe) and a neurohypophysis (anterior lobe).

Adenohypophysis secretes gonadotropic hormones that regulate the function of the ovaries and mammary glands: lutropin (luteinizing hormone, LH), follitropin (follicle-stimulating hormone, FSH), prolactin (PrL) and also somatotropin (STG), corticotropin (ACTG), and Iaccin, ACTH, IGT, I use CTG, CT, IGT, CT, IGT, CTG, CT, IGT, CT, IGT, and hormone GH, hormone GH, hormones;

In the pituitary cycle, there are two functional phases - follicular, with the predominant secretion of FSH, and luteal, with the dominant secretion of LH and PrL.

FSH stimulates follicle growth in the ovary, the proliferation of granulosa cells, together with LH stimulates the secretion of estrogen, increases the aromatase content.

Increased secretion of LH in a mature dominant follicle causes ovulation. Then LH stimulates the excretion of progesterone in the corpus luteum. The dawn of the corpus luteum is determined by the additional effect of prolactin.

Prolactin together with LH stimulates the synthesis of progesterone by the corpus luteum, its main biological role is the growth and development of the mammary glands and the regulation of lactation. In addition, it has a fat mobilizing effect and lowers blood pressure. An increase in the body prolactin leads to disruption of the menstrual cycle.

Currently, two types of gonadotropin secretion have been discovered: tonic, promoting the development of follicles and their estrogen production, and cyclical, providing a phase change of low and high concentration of hormones and, in particular, their preovulatory peak.

The content of gonadotropins in the adenohypophysis fluctuates during the cycle - there is a peak of FSH on the 7th day of the cycle and an ovulatory peak of LH by the 14th day.

Level Four - Ovaries

The ovary is an autonomous endocrine gland, a kind of biological clock in a woman’s body that implements a feedback mechanism.

The ovary performs two main functions - generative (follicle maturation and ovulation) and endocrine (synthesis of steroid hormones - estrogen, progesterone and in a small amount of androgens).

The process of folliculogenesis occurs in the ovary continuously, starting in the antenatal period and ending in postmenopausal women. At the same time, up to 90% of follicles are cutted away and only a small part of them go through the full cycle of development from primordial to mature and turn into a yellow body.

At both ovaries at birth, the girl contains up to 500 million primordial follicles. By the beginning of adolescence due to atresia, their number is halved. For the entire reproductive period of a woman’s life, only about 400 follicles mature.

The ovarian cycle consists of two phases - follicular and luteal. The follicular phase begins after the end of menstruation and ends with ovulation, the luteal phase begins after ovulation and ends with the onset of menstruation.

Usually, from the beginning of the menstrual cycle until the 7th day, several follicles simultaneously begin to grow in the ovaries. From the 7th day one of them is ahead of the others in development, reaches 20-28 mm in diameter by the time of ovulation, has a more pronounced capillary network and is called the dominant one. The reasons for the selection and development of the dominant follicle have not yet been elucidated, but since its appearance, other follicles cease to grow and develop. The dominant follicle contains an egg cell, its cavity is filled with follicular fluid.

By the time of ovulation, the volume of follicular fluid increases by a factor of 100, the estradiol content increases dramatically (E2), the rise in the level of which stimulates the release of LH by the pituitary and ovulation. The follicle develops in the I phase of the menstrual cycle, which lasts on average until the 14th day, and then the ripened follicle breaks - ovulation.

Shortly before ovulation, the first meiosis occurs, i.e., the reduction division of the egg cell. After ovulation, the egg from the abdominal cavity enters the fallopian tube, in the ampullary part of which the second reduction division occurs (second meiosis). After ovulation, under the influence of the primary effect of LH, further growth of granulosa cells and connective tissue shells of the follicle and accumulation of lipids in them are observed, which leads to the formation of the yellow body 1.

The process of ovulation itself is a rupture of the basal membrane of the dominant follicle with the release of the egg, surrounded by a radiant corona, into the abdominal cavity and later on into the ampullar end of the fallopian tube. In case of violation of the integrity of the follicle, there is a slight bleeding from the destroyed capillaries. Ovulation occurs as a result of complex neurohumoral changes in a woman's body (the pressure inside the follicle increases, its wall becomes thinner under the influence of collagenase, proteolytic enzymes, prostaglandins).

The latter, as well as oxytocin and relaxin, alter the vascular filling of the ovary and cause contraction of the muscle cells of the wall of the follicle. The process of ovulation is also influenced by certain immune changes in the body.

An unfertilized egg cell dies after 12-24 h. After its ejection into the cavity of the follicle, the capillaries forming quickly grow in, the granular cells undergo luteinization - a yellow body is formed, the cells of which secrete progesterone.

In the absence of pregnancy, the yellow body is called menstrual, its flowering stage lasts 10-12 days, and then regression occurs.

The inner shell, granular cells of the follicle, the corpus luteum under the influence of pituitary hormones produce sex steroid hormones - estrogens, gestagens, androgens, the metabolism of which occurs mainly in the liver.

Estrogens include three classic fractions - estrone, estradiol, estriol. Estradiol (E2) - the most active. In the ovary and the early follicular phase it is synthesized 60-100 mcg, in the luteal - 270 mcg, by the time of ovulation - 400-900 mcg / day.

Estron (E1) is 25 times weaker than estradiol, its level from the beginning of the menstrual cycle until the moment of ovulation increases from 60-100 mcg / day to 600 mcg / day.

Estriol (Ez) is 200 times weaker than estradiol, it is an inactive metabolite of Ei and E2.

Estrogens (estrus - estrus) when injected into castrated females of white mice cause estrus in them - a condition similar to that of non-castrated females during spontaneous maturation of the egg.

Estrogens promote the development of secondary sexual characteristics, regeneration and growth of the endometrium in the uterus, preparation of the endometrium to the action of progesterone, stimulate the secretion of cervical mucus, contractile activity of smooth muscles of the genital tract, change all types of metabolism with a predominance of catabolism, lower body temperature. Physiological quantities of estrogens stimulate the reticuloendothelial system, increasing antibody production and phagocytic activity, increasing the body’s resistance to infections, inhibiting nitrogen, sodium, and liquid in soft tissues, calcium and phosphorus in bones, and increasing the concentration of glycogen, glucose, phosphorus, creatinine, iron and copper in the blood and muscles, reduce cholesterol, phospholipid and total fat in the liver and blood, accelerate the synthesis of higher fatty acids. Under the influence of estrogens, the metabolism proceeds with a predominance of catabolism (delay in the body's sodium and water, increased dissimilation of proteins), as well as a decrease in body temperature, including basal (measured in the rectum).

The process of development of the corpus luteum can be divided into four phases: proliferation, vascularization, flowering and reverse development. By the time of the reverse development of the yellow body, the next menstruation begins. In the event of pregnancy, the corpus luteum continues to develop (up to 16 weeks).

Progestin(from gesto - wear, be pregnant) contribute to the normal development of pregnancy. Progestins produced mainly by the corpus luteum of the ovary, play a large role in the cyclic changes of the endometrium, occurring in the process of preparing the uterus for implantation of a fertilized egg. Under the influence of gestagens, the excitability and contractility of the myometrium are suppressed while simultaneously increasing its elasticity and plasticity. Progestin along with estrogen play a large role during pregnancy in the preparation of the mammary glands for the upcoming lactation function after childbirth. Under the influence of estrogen, proliferation of the milk ducts occurs, and the gestagens act mainly on the alveolar apparatus of the mammary glands.

Progestin, in contrast to estrogen, have an anabolic effect, i.e., they promote the assimilation (assimilation) by the body of substances, in particular proteins, coming from outside. Progestins cause a slight increase in body temperature, especially the basal.

Progesterone is synthesized in the ovary in the amount of 2 mg / day in the follicular phase and 25 mg / day. - in luteal. Progesterone - the main ovarian progestogen, the ovaries also synthesize 17a-hydroxyprogesterone, D4-pregnenol-20-OH-3, O4-pregnenol-20-OH-3.

Under physiological conditions, gestagens reduce the content of amino nitrogen in the blood plasma, increase the secretion of amino acids, increase the separation of gastric juice, inhibit bile secretion.

The following androgens are produced in the ovary: androstenedione (testosterone precursor) in an amount of 15 mg / day, dehydroepiandrosterone and dehydroepiandrosterone sulfate (also testosterone precursors) in very small amounts. Small doses of androgens stimulate the function of the pituitary gland, large - block it. The specific effect of androgens can manifest itself in the form of a viril effect (clitoris hypertrophy, male-type hair growth, prolapse of cricoid cartilage, the appearance of acne vulgaris), anti-estrogenic effect (in small doses cause proliferation of the endometrium and vaginal epithelium), gonadotropic effect (in low doses stimuli). , promote growth, maturation of the follicle, ovulation, the formation of the corpus luteum), antigonadotropic effect (high concentration of androgens in the preovulatory period suppresses ovulation and causes further follicle atresia).

Protein hormone inhibin, which inhibits the secretion of FSH by the pituitary, and protein substances of a local effect, oxytocin and relaxin, are also formed in the granulosa cells of the follicles. Oxytocin in the ovary promotes regression of the corpus luteum. Prostaglandins are also formed in the ovaries. The role of prostaglandins in the regulation of the reproductive system of a woman is to participate in the ovulation process (ensure rupture of the wall of the follicle by increasing the contractile activity of the smooth muscle fibers of the sheath of the follicle and reducing the formation of collagen) in the transport of the ovum (affect the contractile activity of the fallopian tubes and affect the myometrium, contributing to blastocyst), in the regulation of menstrual bleeding (the structure of the endometrium at the time of its rejection, the contractile activity of the myometrium, arte IOL, platelet aggregation is closely related to the synthesis of prostaglandins and decay processes).

In the regression of the corpus luteum, if fertilization does not occur, prostaglandins are involved.

All steroid hormones are formed from cholesterol, gonadotropic hormones are involved in the synthesis: FSH and LH and aromatases under the influence of which estrogens are formed from androgens.

All of the above cyclic changes occurring in the hypothalamus, the anterior lobe of the pituitary and the ovaries are now commonly referred to as the ovarian cycle. During this cycle, complex relationships take place between the hormones of the anterior pituitary and peripheral sex (ovarian) hormones. Schematically, these relationships are depicted in Fig. 1, from which it is clear that the greatest changes in the secretion of gonadotropic and ovarian hormones occur during the maturation of the follicle, the onset of ovulation and the formation of the corpus luteum. So, by the time of the onset of ovulation, the greatest production of gonadotropic hormones (FSH and LH) is observed. With the maturation of the follicle, ovulation and partly with the formation of the corpus luteum, estrogen production is associated. For the production of gestagens directly related to the formation and increase of activity of the corpus luteum.

Under the influence of these ovarian steroid hormones, the basal temperature changes, with a normal menstrual cycle, its distinct biphasic state is noted. During the first phase (before ovulation) the temperature is a few tenths of a degree below 37 ° C. During the second phase of the cycle (after ovulation), the temperature rises a few tenths of a degree above 37 ° C. Before the start of the next menstruation and in the process, its basal temperature again drops below 37 ° C.

The hypothalamus-pituitary-ovaries system is a universal, self-regulating super-system that exists due to the implementation of the feedback law.

The law of feedback is the basic law of the functioning of the endocrine system. There are negative and positive mechanisms. Almost always during the menstrual cycle the negative mechanism works, according to which a small amount of hormones in the periphery (ovary) causes the release of high doses of gonadotropic hormones, and with an increase in the concentration of the latter in the peripheral blood, the stimuli from the hypothalamus and pituitary decrease.

The positive feedback mechanism is aimed at providing an ovulatory peak of LH, which causes rupture of the mature follicle. This peak is due to the high concentration of estradiol produced by the dominant follicle. When the follicle is ready to rupture (just as the pressure in the steam boiler rises), the valve in the pituitary gland opens and a large amount of LH is immediately released into the blood.

The feedback law is carried out on a long loop (ovary - pituitary), short (pituitary - hypothalamus) and ultrashort (gonadotropin-releasing factor - hypothalamic neurocytes).

В регуляции менструальной функции большое значение имеет осуществление принципа так называемой обратной связи между гипоталамусом, передней долей гипофиза и яичниками. Принято рассматривать два типа обратной связи: отрицательную и положительную. With отрицательном типе обратной связи the production of central neurohormones (releasing factors) and adenohypophysis gonadotropins is inhibited by ovarian hormones produced in large quantities. With positive type of feedback The release of releasing factors in the hypothalamus and gonadotropins in the pituitary gland is stimulated by low levels of ovarian hormones in the blood. The implementation of the principle of negative and positive feedback underlies the self-regulation of the function of the hypothalamus-pituitary-ovary system.

Cyclic processes under the influence of sex hormones occur in other target organs, which in addition to the uterus include tubes, vagina, external genitals, mammary glands, hair follicles, skin, bones, adipose tissue. The cells of these organs and tissues contain receptors for sex hormones.

These receptors are found in all structures of the reproductive system, in particular in the ovaries - in the granulosa cells of the mature follicle. They determine the sensitivity of the ovaries to pituitary gonadotropins.

In the breast tissue are receptors for estradiol, progesterone, prolactin, which ultimately regulate the secretion of milk.

Level Five - Target Cloths

Target tissues are points of application for the action of sex hormones: genitals: the uterus, tubes, cervix, vagina, mammary glands, hair follicles, skin, bones, adipose tissue. The cytoplasm of these cells contains strictly specific receptors for sex hormones: estradiol, progesterone, testosterone. These receptors are in the nervous system.

Of all the organs of the targets, the greatest changes occur in the uterus.

In connection with the process of reproduction, the uterus consistently performs three main functions: menstrual, necessary for preparing the organ and especially the mucous membrane for pregnancy, the function of the fetal stem to ensure optimal conditions for the development of the fetus and the fetus function during the birth process.

Changes in the structure and function of the uterus in general, and especially in the structure and function of the endometrium, occurring under the influence of ovarian sex hormones, are called uterine cycle. During the uterine cycle, there is a sequential change of the four phases of cyclic changes in the endometrium:

1) proliferation, 2) secretion, 3) desquamation (menstruation), 4) regeneration. The first two phases are considered as basic. That is why the normal menstrual cycle is called biphasic. A well-known boundary between these two main phases of the cycle is ovulation. There is a clear correlation between changes occurring in the ovary before and after ovulation, on the one hand, and the successive change of phases in the endometrium, on the other hand (Fig. 4).

First main proliferation phase The endometrium begins after the completion of the regeneration of the mucous membrane that was torn off during the preceding menstruation. The functional (surface) layer of the endometrium, which arises from the residues of the glands and stroma of the basal part of the mucous membrane, participates in the regeneration. The onset of this phase is directly related to the increasing effect on the uterine mucosa of estrogens produced by the aging follicle. At the beginning of the proliferation phase, the endometrial glands are narrow and even (Fig. 5, a). As proliferation increases, the glands increase in size and begin to squirm slightly. The most pronounced proliferation of the endometrium occurs at the time of full maturity of the follicle and ovulation (12-14 day 28-day cycle). The thickness of the uterine mucosa by this time reaches 3-4 mm. At this point, the phase of proliferation ends.

Fig. 4. The relationship between changes in the ovaries and the lining of the uterus during the normal menstrual cycle.

1 - follicle maturation in the ovary - proliferation phase in the endometrium, 2 - ovulation, 3 - formation and development of the corpus luteum in the ovary - endometrial secretion phase, 4 - reverse development of the corpus luteum in the ovary, endometrial rejection - menstruation, 5 - beginning of maturation of the new body follicle in the ovary - the phase of regeneration in the endometrium.

Second main secretion phase The endometrial glands begin under the influence of the rapidly increasing activity of gestagens, produced in increasing amounts by the corpus luteum of the ovary. The endometrial glands twist and fill more and more with a secret (Fig. 5, b). The stroma of the uterus mucous membrane swells, it is penetrated by spirally convoluted arterioles. At the end of the secretion phase, the endometrial glands of the glands acquire a sawtooth shape with accumulation of secretion, glycogen content and the appearance of pseudodecidual cells. It is by this time that the uterine mucosa is fully prepared for the perception of a fertilized egg.

If after ovulation fertilization of the egg does not occur and, accordingly, pregnancy does not occur, the corpus luteum begins to undergo a reverse development, which leads to a sharp decrease in the content of estrogen and progesterone in the blood. As a result, foci of necrosis and hemorrhage appear in the endometrium. Then the functional layer of the uterine mucosa is rejected and the next menstruation begins, which is the third phase of the menstrual cycle - desquamation phaselasting on average about 3-4 days. By the time the menstrual bleeding stops, the fourth (final) phase of the cycle begins - regeneration phaselasting 2-3 days.

The above-described phase changes in the structure and function of the mucous membrane of the uterus are significant manifestations of the uterine cycle.

What are menstrual bleeding?

Menstruation consists of blood and the surface of the uterus.

The first day of bleeding is the beginning of the menstrual cycle.

This period lasts from three to seven days, while the woman loses 3-5 tablespoons of blood.

Some women have heavy bleeding, however, medical methods can cope with this if menses cause anxiety.

What happens during ovulation?

Ovulation - is the release of eggs from the ovaries. A woman is already born with a full set of eggs. During each menstruation, 1-2 eggs are removed from the female body. After ovulation, the egg lives 24 hours. If more than one egg is hatching at a time, the subsequent ones are produced together with the first one during these 24 hours.

Pregnancy occurs when the male sperm reaches the egg and fertilizes it. Sperm can remain in the fallopian tubes for up to seven days after intercourse. If there was no ovulation, then the woman may not become pregnant.

Some hormonal methods of contraception (such as birth control pills and injections) are aimed just at stopping the ovulation process.

When is it possible to conceive?

Theoretically, a woman can become pregnant only during the short time when ovulation occurs.

It is very difficult to determine when ovulation really occurs, unless you contact the specialists of family planning centers.

In most women, it occurs 10-16 days before the next menstruation.

If you know in advance the moment of possible conception, you can plan a pregnancy or, on the contrary, prevent it. But in this case it is still better to seek help from doctors who are knowledgeable in this field. They will follow the vaginal secretions, daily temperature and menstruation cycle, in order to more accurately track the point of onset of ovulation.

It is very rash to assume that conception is possible only on the 14th day after the menstruation. This statement is only suitable for women with an average menstrual cycle of 28 days, and with an increased or shortened cycles, this moment shifts.

Menstrual cycle and pregnancy - video

The obstetrician-gynecologist answers the questions concerning conception and pregnancy:

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Monthly cycle and pregnancy: direct relationships

The cycle of menstruation and pregnancy are two closely related processes. Only with a regular (normal) monthly cycle, a woman can become pregnant, bear and give birth to a baby. Any disorders of the monthly cycle reduce its chances for fertilization many times, therefore, the woman’s general well-being and her reproductive function depend on the body’s work, the presence of various diseases and stresses. Moreover, the possibility of becoming pregnant is directly related to the day of the monthly cycle.

The monthly cycle is the time period from one menstruation to the next. The norm of the cycle duration is 21-38 days. The menstrual cycle is divided into two phases. In the first phase, which lasts 14 days, the body begins to prepare for a probable pregnancy. In one of the ovaries under the influence of follicle-stimulating hormone, an egg cell grows. At the same time, a female hormone such as estrogen starts to be released into the blood. In the middle of the cycle (approximately on the 14th day) ovulation occurs. The egg cell leaves the ovary and moves through the fallopian tube, if it encounters a sperm cell on its way, fertilization will occur.

The main hormone of the second phase of the cycle is progesterone. In this phase, the mucous uterine layer is prepared for implantation of a fertilized egg. If fertilization does not occur, the level of hormones in the body drops sharply, and after a few days a new monthly cycle begins. An unfertilized egg with blood and particles of exfoliated endometrium is excreted from the body.

How to calculate pregnancy by month

When a woman finds out that she is pregnant, and soon becomes a mother, she immediately has a lot of experiences and questions. And, as a rule, the most important of the main questions, when does the future mother have to give birth.

To determine the date of birth, you need to know the exact duration of pregnancy. As a rule, it is determined by a gynecologist when examined by a specialist during an ultrasound examination. But the woman herself can easily calculate the gestational age by the month. The main thing to remember is the date of the last menstrual period.

In practice, they share the real pregnancy and obstetric, the difference between them is 14 days. These two weeks - the time interval between the beginning of the last menstruation and ovulation, occurring approximately on the 14th day of the monthly cycle. To determine the duration of pregnancy by monthly it is necessary to subtract 14 days from the obstetric term, and this will be the actual duration of pregnancy calculated from the day of conception. But it is necessary to know that obstetric pregnancy continues not nine normal months, but ten obstetric months, consisting of 28 days.

It is also possible to calculate the gestational age by monthly using the method proposed by the German scientist Negele. To do this, you need to subtract three months from the date of the beginning of the last menstruation, and then add seven days to the received date - this will be the date of the expected birth. It facilitates calculations. It is important to take into account when calculating that pregnancy lasts on average about 40 weeks from the date of the last menstrual period.

In addition, to calculate the duration of pregnancy monthly, you can, using the online calendar.

Can monthly go during pregnancy

Such a phenomenon as the first menstruation during pregnancy is understandable. It often happens that the signal about implantation of a fertilized egg to the body did not arrive on time, so the hormonal background was not completely rebuilt, and as a result, the menstrual period went. In this case, the monthly during pregnancy are not abnormal. Once the body is completely rebuilt, they will stop.

A very rare cause of menstruation during pregnancy can be maturation in different ovaries of two eggs in one cycle. Only one of the eggs is fertilized, the other with the endometrium exfoliates, as a result of which menstruation occurs.

It should be noted that the monthly during pregnancy can go only in the first month. The appearance of bleeding in the later stages of pregnancy should alert the woman. The cause of this phenomenon can be an imbalance of hormones in the body, caused by environmental problems, inflammation, stress, medication, various diseases, so in this case you should consult a doctor and undergo a medical examination.

Spotting in pregnant women can also occur due to the detachment of the ovum. The reasons may be as follows:

  • insufficient progesterone production. If the function of the corpus luteum is impaired, the amount of progesterone insufficient to maintain the pregnancy is produced in the pregnant woman's body. For the treatment of this disorder, the doctor prescribes drugs that are analogues of progesterone,
  • the egg was attached at the site of endometriosis or myoma node. In this case, the ovum is poorly supplied with blood and its rejection occurs,
  • hyperandrogenism. An overabundance in the body of male sex hormones (androgens) can lead to the rejection of the ovum. This pathology is also treated with the help of drug therapy,
  • cessation of egg development as a result of malformations in the formation of genital organs and genetic abnormalities. These violations are treated in the hospital under the direct supervision of a doctor.

Bleeding can often occur when the embryo is rejected. If the discharge is abundant, there are increasing pain, fever, immediately call a doctor.

Some women are interested in: "When ectopic pregnancy go monthly?". Medical experts say that the onset of menstruation with ectopic pregnancy is impossible because of the action of the hormone progesterone. Often, women take for her bleeding, resulting from the rejection of the ovum. These secretions are usually scanty and are accompanied by lower abdominal pain. If the pain becomes severe and acute, and there is heavy bleeding, it means that the fallopian tube has ruptured, in this case an emergency surgical operation will be required.

Pregnancy test for menstruation

If you have symptoms such as nausea, abdominal pain, menstrual flow is not the same as usual, do a pregnancy test. It is better to spend it in the morning, immediately after waking up, since it is at this time that the concentration of the pregnancy hormone in the body is highest.

If the test indicates the presence of pregnancy, immediately consult a doctor. After all, monthly during pregnancy is not normal. Even scanty bleeding during pregnancy requires a mandatory consultation with a doctor. After all, if they have arisen at a gestational age of more than four weeks, much can already be done to save the future baby, and timely diagnosis of ectopic pregnancy can even save a woman’s life.

Take care of your own health, regularly undergo examinations with a gynecologist, lead a healthy lifestyle.

Short menstrual cycle - causes of shortening the cycle, whether treatment is necessary

The duration of the menstrual cycle for each woman depends on the individual characteristics of the organism. Normally, the cycle should be from 3 weeks to 34 days and be accompanied by moderate blood loss. In this regard, one of the reasons for concern should be the reduction of the menstrual cycle.

If previously its duration was within the normal range, then drastic reductions could indicate reproductive problems or endocrine diseases. In addition, for shortening the cycle, a woman can take uterine bleeding, and a woman cannot diagnose them, distinguish them from menstruation, and the more so eliminate their causes.

Therefore, if the menstrual cycle has become shorter and bleeding has changed the nature - this should be the reason for an immediate visit to the doctor. This applies to women of any age. Such cycle changes may indicate a disease, an ectopic pregnancy, or may be due to physiological causes.

But in any case, only a doctor can establish this accurately.

Causes and symptoms of disorders associated with the shortening of the monthly cycle

The main abnormalities that women can note in themselves relate to changing the timing of the onset of menstruation:

  1. Menstruation comes every 15-17 days, may be regular and irregular.
  2. Bleeding is greatly reduced, sometimes turning into a spotting that lasts 2-3 days.
  3. Changes in the duration of the cycle occurred suddenly for no apparent reason.
  4. A woman cannot become pregnant due to the lack of ovulation.

Any violation of the menstrual cycle should be a reason for careful examination, since the cause of the changes can be various diseases that require immediate treatment.

Physiological causes leading to cycle shortening

The most common causes of changes in the duration of menstruation are overwork and severe, prolonged stress.

It is established that stressful situations cause changes in hormonal levels and an increase in the blood hormone prolactin.

In order to normalize the cycle, it is absolutely necessary to get enough sleep, to reduce stressful situations to a minimum and to increase the body’s resistance to nerve loads.

Если значительно сократился менструальный цикл, причина может быть связана с авитаминозом. Недостаток некоторых витаминов (группы В, А, К и Е) вызывает нарушение обмена веществ и изменяет свертываемость крови. В данном случае прием специальных препаратов окажет положительное воздействие на репродуктивную систему.

The shortened cycle can be after childbirth, abortion, miscarriage, which is a temporary phenomenon. Often, menstruation becomes irregular in the first stage of menopause, which is also not cause for alarm.

Taking certain medications, including antibiotics, can also cause an “early” onset of menstruation, but this phenomenon is a one-off process.

Sharp climate change, for example, when moving or during a holiday in a resort, can have changes in the reproductive system.

Sometimes the monthly cycle is completely rebuilt after the birth of the child and becomes shorter. If this happens every month, then a woman needs no hormonal or other treatment.

Sometimes for an episodic shortening of the cycle, a woman takes a spontaneous miscarriage that occurred in the first week of pregnancy, when the woman does not even know about her new position. Bleeding at the same time indistinguishable from menstruation, occurred prematurely.

Diseases that can cause a shortening of the cycle:

  1. Inflammatory processes in the ovaries.
  2. Ovarian cyst.
  3. Uterine fibroids.
  4. Blood clotting disorders.
  5. Diseases of the thyroid gland.
  6. Diabetes.
  7. Kidney disease.
  8. Metabolic changes.
  9. Vascular diseases.

To determine the exact cause of the cycle change, it is necessary to pass an examination by specialists and pass the necessary tests.

Acceptance of hormones as a reason for reducing the menstrual cycle

At first, when you receive OK, lung or more intense bleeding may occur, occurring on days 14-19 after the start of hormones. In this case, it is not about menstruation, but about bleeding. After 2-3 months of oral contraceptives, this phenomenon will cease.

If the bleeding will appear in the future, then you should discuss with your doctor the possibility of additional intake of antioxidants and vitamin E, since oral contraceptives provoke depletion of these substances in the body, and a lack of vitamin E is the cause of hemorrhage.

In particular, the Synergin antioxidant complex is intended for such purposes.

Pregnancy and short cycle

If a woman has a permanent sexual partner and in recent times she had unprotected sex, the first possible cause of a change in the cycle should be considered pregnancy.

She may be normal or ectopic, so it is necessary not only to use the pharmacy test for pregnancy, but also to visit the antenatal clinic. Bleeding in an ectopic pregnancy a woman can take for a short cycle.

Also in the first 3 months of pregnancy, some women may have a spotting effect that takes 1-2 days.

A few words need to say and nursing mothers. During the entire lactation period, the monthly cycle may be unstable: very short or long. The reason is the restructuring of the female body and a large amount of the hormone prolactin in the blood of a woman. It prevents the onset of a new pregnancy, and hence the restoration of the normal duration of menstruation.

Short menstrual cycle: whether treatment is necessary

If a woman is diagnosed with abnormalities in the development of internal organs, inflammatory processes, neoplasms or endometriosis, the doctor will prescribe the appropriate therapy. Depending on the cause, the drugs will vary.

So, to restore the cycle after taking oral contraceptives, on the background of stress or for unresolved reasons, the complex Pregnoton is intended. It does not contain hormones, but helps to normalize the cycle and restore hormonal balance.

In its composition the plant component is Vitex extract, which affects the increased level of prolactin, arginine, which improves blood circulation in the pelvic organs, as well as vitamins and minerals, which are important for the work and regulation of the reproductive system organs.

What is ovulation and the menstrual cycle?

The menstrual cycle is controlled by hormones. Thus, every month the female body is prepared for conception. What is menstruation?

So, menstruation - regular bleeding, the process occurs due to the rejection of the endometrium. The endometrium itself is lined in the cavity of the female organ (in the uterus).

As a rule, the cycle duration is at least 35 days. Note that in adolescents, the cycle is slightly longer, it lasts for 45 days.

In the first phase, an increase in estrogen occurs, which in turn is responsible for the strength of the bones, as well as for the growth of the endometrium.

notethat the release of the egg, in medicine called ovulation, begins approximately in the middle of the cycle. According to statistics, it was recorded that this is approximately the 14th day, but only under the condition that the entire menstrual cycle has a duration of 28 days.

Can there be monthly during pregnancy?

In the first month, the young mother may not be suspicious of what is in the position. As you remember, conception occurs in the middle of a cycle, and implantation of the ovum may last for 7-15 days. Of course, during this period of time hormones simply do not have time to restructure.

Important! It depends on the hormonal background survival rate of the embryo.

When should menstruation begin after childbirth?

The term of the onset of menstruation is primarily a matter of how much the baby is feeding.

For those who do not know, there are such types of feeding:

  1. artificial
  2. mixed
  3. natural feeding.

Each mom should understand that the production of breast milk occurs only under the action of the pituitary hormone, as well as under the action of prolactin.

The menstrual cycle after giving birth to a nursing mother, what happens? As you can see, estrogen does not increase during this period. Therefore, when the mother breastfeeds the baby, then at this time menstruation can begin.

If the baby is bottle-fed after delivery, what happens? In this case, a woman’s cycle can recover within 6 months.

Important! During this period, ovulation also occurs, so a woman can become pregnant again.

If the baby is on mixed feeding, then complete postpartum recovery will come in 4 months.

How long are the monthly in the postpartum period?

The first periods are usually abundant, so blood clots can also be observed. After cesarean section, the menstrual cycle lasts a long time, as there was surgery in the uterus. A woman needs to change the gasket every hour, if there is a very strong discharge, it is necessary to tell the doctor about it. Otherwise, you can skip the increasing bleeding.

In some women, the menstrual cycle after cesarean section is accompanied by a smear. This period can last for one month.

Why is it impossible to quickly restore the menstrual cycle? The answer to this question is complex, so we consider additional factors that affect the recovery period of the menstrual cycle, immediately after childbirth.

Main factors:

  1. If a woman is Caesar, the main reason is the difficulty in caring not only for the child, but also for herself. The uterus and suture for 3-4 months is very painful, therefore it hinders the movements of the young mother.
  2. Unhealthy food mom.
  3. If the woman had postpartum depression.
  4. With early conception or with late childbirth.

Additional factors must include associated diseases. For example: asthma or diabetes. After all, with such diseases, you must adhere to hormone therapy, so the recovery period will be long.

Is it possible to restore the menstrual cycle after childbirth, when there were complications? Yes, but the recovery period is long, especially if the woman had Sheehan syndrome as a complication.

Pathology of menstruation after childbirth

Bleeding can also be pathological. At this point, a woman should immediately see a doctor, and not wait until her period is restored.

When to see a doctor:

  1. If suddenly stopped selection. In this case, you must immediately contact a gynecologist, because it indicates a bend of the uterus or speaks of the accumulation of a lohiometer.
  2. If the last couple of months, monthly scanty. This means that hormonal disorders occur in a woman’s body.
  3. Consider carefully according to the calendar, if within 6 months you have irregular periods, consult a doctor. Otherwise, you can skip the pathology of the ovaries.
  4. Pain in the abdomen, unpleasant smell of discharge and color change, says about the infection.

Remember, if you do not go to the doctor in time, there is a risk of complications.

Abortion and menstruation

Many have a question, after an abortion, what is the menstrual cycle?

Everyone understands that abortion is a surgical operation in which vessels are damaged, thereby causing blood loss. After surgery, a wound remains on the uterus. Bleeding lasts until the vessels stop cracking.

Note, some women after an abortion, in general, there is not any discharge.

Doctors have abortions only for women whose gestational age does not exceed 20 weeks.

Important! It is believed that when a woman was curetted out of the uterus, this is the first day of the menstrual cycle.

What influences the recovery cycle after an abortion?

  • In the first place - the type of operation (what kind of abortion was), as well as how long it takes.
  • The second factor is the level of professionalism, the medications used and the general condition of the woman.

As practice shows, MCs after any type of abortion are restored within 6 months.

Short menstrual cycle: what are the reasons?

The menstrual cycle is an indicator of women's health. When the cycle is regular and without any unusual symptoms, the woman can be sure that her genital organs are in order. Each woman has her own individual cycle: for someone it is short-term, and for someone it is long. He must recover after two years after the girl first began her period.

Do I need to worry if the short menstrual cycle?

Short cycle: how to define?

The reasons for which the menstrual cycle can be short, very much. But the main thing to know is that a small cycle is considered a deviation. Sometimes these abnormalities can be associated with physiological causes that are not related to any serious diseases. But even the slightest deviation from the norm can lead to infertility.

But still, a short cycle is a signal that needs attention. A short cycle that lasts less than 21 days may indicate that you have problems. They can cause infertility or other diseases.

The normal cycle is 28 days. But it is also acceptable when a woman has a menstrual cycle from 21 days to 36.

If the cycle of menstruation, which lasts less than 21 days is a physiological feature of the body, you should not worry, but still you should visit a doctor and establish the reasons.

If initially the cycle duration was normal and suddenly it was drastically reduced, then a visit to the gynecological department is mandatory.

Symptoms of a short cycle of menstruation:

  • if the duration of the menstrual cycle is less than 21 days. A cycle that lasts 21-36 days is the norm. The ideal option is 28 days,
  • menstruation occurs often every 2 weeks,
  • spotting last less than normal, i.e. even less than 3 days
  • a scanty character (daub),
  • obvious reasons that shorten the cycle.

Causes of a short monthly cycle

The reasons why the monthly cycle became short may be different. Sometimes they can be determined independently, but in some cases a woman may not be aware of the presence of problems in the reproductive system.

  1. Endocrine system. A woman may have problems with the thyroid or adrenal glands. These diseases may well be the cause of short menstruation. It is possible that diseases that are chronic in nature may shorten the cycle.
  2. The presence of various infectious diseases. Inflammatory processes can also shorten the cycle.
  3. Lack of vitamins. It is possible that a woman has a deficiency of such vitamins as K and C.
  4. Defects of the genital organs. Incorrectly developed genitals, for example, the bend of the uterus.
  5. Diets. Rapid weight loss, rapid weight loss can lead to shortening of the cycle. This is due to the fact that a woman limits herself to eating and will not receive the right amount of useful and necessary enzymes. If you exhaust yourself with terrible diets, your periods can disappear altogether.
  6. Contraceptives. Perhaps this is not at all monthly, if the woman has very scanty (daub) during menstruation, then this is a serious problem, an urgent need to consult a doctor. For example, if a woman takes contraceptive contraceptives, then the first 3 months a short cycle is the norm, but if the problem is still relevant after 3 months, see a doctor immediately. Perhaps the doctor will recommend another type of contraception.
  7. Pregnancy. A shortened cycle may hint about the presence of a pregnancy, both normal and abnormal (ectopic). Therefore it is necessary, the faster, the better to establish the cause. But to get an accurate result is possible, only at the doctor.
  8. Endometriosis. A serious reason why the cycle is reduced. This is a disease in which endometrial tissue increases in volume in the uterine cavity. Treatment may require both surgery and hormone therapy. It is possible to establish such a reason on your own, drawing attention to the color of bleeding: with endometriosis, the blood is dark, and during normal menstruation it is red.
  9. Climax. The functions of the genital organs are oppressed. This suggests that a woman can no longer have children. The ovum ceases to mature, and the ovaries produce progesterone and menopause occurs. To determine the exact cause, consult a doctor.
  10. Common causes: change of climatic conditions, overwork, menopause, tumors, fibroids, cyst, recovery after childbirth or pregnancy, and also if the woman has had an abortion or miscarriage.

Is it worth sounding the alarm?

A short cycle is considered normal in adolescent girls. Do not worry if the monthly teenage girl go 2 days. It is also not scary if the cycle is irregular and can be very short. The first 2 years, the cycle is only restored and returns to normal.

During the carrying of the child, the woman has no monthly periods, and in the postpartum period, the cycle resumes again and may be shorter. In time, he will recover.

Breastfeeding affects the cycle. After the woman finishes feeding, he must recover.

Woman's health is important, so watch your health. any deviations from the norm, including a short menstrual cycle, affect the conception and childbearing.


Short menstrual cycle: how to reach the cherished 22 and more?

Every month in the body of a woman develop changes aimed at preparing for pregnancy. Ovulation occurs - the release of a ripe egg from the ovary, the uterine mucosa is prepared for implantation.

If the pregnancy has not come, the endometrium is rejected, and at this time menstruation occurs, after which a new egg begins to mature in the ovaries.

A short menstrual cycle is usually associated with hormonal changes in the body and can cause difficulties with conception.

The normal duration of the menstrual cycle is 21 to 35 days for adult women, and 21 to 45 days for adolescents.

The cycle of 22 days is at the lower limit of the norm, and at the same time, the woman needs a gynecologist's consultation, especially if she cannot become pregnant.

Difficulties with conception with a short intermenstrual interval are associated with too small an interval between the beginning of the development of the egg and the period of ovulation. During this time, the oocyte does not have time to mature for fertilization.

Causes of shortening the cycle

A short menstrual cycle (17–18 days) may occur for the following reasons:

  • The onset of menstruation in adolescents

In the first 2-3 years, the length of the menstrual cycle in girls can vary significantly. At this stage, a reduction in the time between the days of the onset of menstruation is common, sometimes they happen 2 times a month. It is necessary to immediately teach the girl to keep a calendar of menstruation, in time to suspect hormonal disorders in a child.

Read more about how the menstrual cycle is established in adolescent girls, what is considered the norm, and what is a violation, see our separate article.

In women after 45 years of age, the duration of the menstrual cycle may change, which may become longer or shorter. In the absence of gynecological diseases, this is normal. Gradually, the shortened menstrual intervals become longer and longer, until they stop.

Constantly short intervals between periods can be a manifestation of serious diseases associated with hormonal disorders.

For example, thyroid hormones, produced in excess in hyperthyroidism, change the formation of hormonal substances in the ovaries. Also, the cause of the disease can be a disease or syndrome Cushing.

For many women, rapid weight loss or weight gain is important.

Причиной может стать миома матки, киста или синдром поликистозных яичников, а также воспалительные заболевания придатков.

Sometimes the triggering factor is taking hormonal contraceptives or clostilbegit, as well as the pathology of the pituitary gland - hyperprolactinemia, which occurs when it has a benign tumor (adenoma).

Prolactin suppresses the maturation of the egg, causing anovulation and premature onset of menstruation. At the same time, the disease may be accompanied by discharge from the mammary glands in the absence of breastfeeding.

Any intense external impact, emotional stress, physical trauma, time zone and climate change, even in healthy women, can cause premature death of an egg that ripens in the ovaries, with the following menstruation beginning earlier than usual. This condition is considered normal if it occurs 1-2 times a year.

Sometimes a small implant bleeding that occurs when a fertilized egg penetrates the uterus mucosa is taken for too early menses. What distinguishes these states is that the implantation bleeding during pregnancy lasts only 1-2 days, and there is little blood release. In addition, after it the monthly is not renewed during the entire period of pregnancy.

Restoration of menstruation after childbirth usually occurs on the 6th - 8th month even against the background of breastfeeding, although this period can vary greatly in different women and even after different pregnancies. This process takes place individually, so after delivery it is possible to establish a short menstrual cycle.

It should be normalized within 1-2 months. As soon as menstruation occurs, a woman can become pregnant again, even if she continues to breastfeed. Therefore, the appearance of menstruation should serve as a signal to protect against new pregnancy, if it is undesirable.

If the cycle time is not restored within 2-3 months, it is recommended to contact a gynecologist.

On the timing of the restoration of menstruation after childbirth, read the link.

It is observed in healthy women. Other causes of anovulation are head injuries, encephalitis, pituitary adenoma, ovarian resistance syndrome, and hormone-active tumors of other organs.

This disease is caused by hormonal disorders. It is accompanied not only by a short interval between periods, but also by abundant, prolonged menstrual bleeding. Often the condition proceeds along with endometriosis.

Conditions in which consultation of the doctor is necessary

The probability of a short menstrual period increases if the patient's blood relatives have cases of uterine fibroids or early menopause.

It is necessary to make an appointment with a gynecologist in such cases:

  • pain in the lower abdomen, which persists for more than two days,
  • menstruation is very intense
  • between the monthly appear bloody discharge, which can be mistaken for a short cycle,
  • pain during sexual intercourse,
  • severe menstrual pain.

Consequences of a shortened menstrual period

A short menstrual cycle can adversely affect the ability to become pregnant. This is explained by the following states:

  • Lower quality ovum

Short intervals between menstruation are associated with the underdevelopment of a normal egg in the ovary. Especially often this occurs in women after 40 years. With increasing age, there is a tendency to reduce the duration of the first phase, that is, before ovulation. If the egg does not have enough time for development (normally it is 12-14 days), it can often not be fertilized.

If the second phase is reduced mainly, the uterine mucosa does not have time to prepare for the implantation of the embryo, and the probability of pregnancy also decreases.

The cycle length of the day of ovulation (how to determine) is influenced more than any other factor. Normally, it should begin on the 14th day.

If it occurs before 11 days, even in a young, gynecologically healthy woman, an unripe egg leaves the ovary. The follicle remaining after it is also functionally immature and cannot turn into a full-fledged yellow body.

Therefore, he cannot synthesize enough progesterone to prepare the endometrium for implantation.

Therefore, with a constantly short menstrual cycle, it is better to contact a gynecologist. The doctor will prescribe a temporary hormone therapy, after which this interval will be lengthened, and the probability of a normal pregnancy will increase significantly.

Possible complications

In addition to difficulties in conceiving, frequent menstruation can lead to chronic iron deficiency anemia. Her symptoms are:

  • fast fatiguability,
  • headache,
  • constant weakness
  • dizziness,
  • shortness of breath with a small load,
  • cardiopalmus.

This condition requires treatment with iron preparations.


To find out the reasons for a short menstrual cycle, you need to contact a gynecologist. After clarification of complaints, medical history and examination of the patient, the doctor may prescribe such studies:

  1. General and biochemical blood tests for recognition of anemia, as well as severe chronic liver and kidney disease, which can cause abnormalities.
  2. Vaginal smear on the microflora to detect infections of the genital tract.
  3. ELISA or PCR blood tests for the diagnosis of genital infections affecting the appendages (chlamydia).
  4. Blood tests for hormones: follicle-stimulating, luteinizing, prolactin, estrogens, thyroxin and thyroid-stimulating hormone.
  5. Ultrasonography of the uterus and appendages to detect the pathology of these organs (fibroids, cyst, chronic adnexitis).
  6. CT or MRI of the brain with suspected pituitary adenoma.

The patient is recommended to keep a schedule of basal temperature and menstrual cycle.

If it is suddenly reduced, for example, after stimulating ovulation, in patients over 40 years of age, if an ovarian tumor is suspected or its depletion syndrome is prescribed, a more in-depth examination is required - an analysis of ovarian reserve. It includes 2 main studies - a blood test for inhibin B and the so-called anti-Muller hormone.

If the menstrual cycle has become shorter and does not recover within 2-3 months, it is necessary to establish and eliminate the cause of this condition:

  1. If the problem is caused by hormonal disorders, in particular, anovulation, they should be diagnosed and normal hormone levels restored.
  2. If there is hyperthyroidism, it is necessary to appoint thyreostatics or surgery on the thyroid gland.
  3. Treatment of uterine fibroids is the appointment of hormonal drugs, minimally invasive interventions (eg, uterine artery embolization) or surgery (conservative myomectomy, hysterectomy).
  4. When infectious diseases are prescribed antibacterial drugs.
  5. If a woman is regularly exposed to stress and on this basis she has a short menstrual cycle, it is necessary either to eliminate stressful situations, or to learn to manage her emotions while maintaining emotional balance.
  6. Additionally prescribed multivitamins, physiotherapy, general massage. Therapeutic gymnastics is useful (exercises are selected depending on the reason for the changes), swimming, walking at a moderate pace.

Treatment of a short menstrual cycle most often includes the use of tablets, patches, rings, intrauterine devices, containing female hormones. The gynecologist should pick them up after examining the patient. Therapy usually takes 4 to 6 months.

From the means of traditional medicine in addition to the main treatment can be taken:

  • fresh juice of viburnum or berries, pounded with a small amount of sugar, or a mixture of viburnum and honey in a teaspoon 1-2 times a day,
  • decoction of root devayasila, onion peel 1 tablespoon twice a day,
  • an infusion of calendula flowers and tansy leaves, which can be brewed as tea, and with extra bitterness of the drink, add honey to it,
  • berries of wild strawberry, which can be eaten fresh, freeze them or make jam.

Dietary supplements to normalize the short cycle, which are sold in pharmacies and are becoming increasingly popular, can be taken only after consulting a doctor. In many cases, they will be ineffective if you do not simultaneously begin taking hormones.


The reasons for the short menstrual cycle are varied, so for the prevention of this condition, you can only give general recommendations:

  1. Avoid stressful situations, sudden intense physical exertion.
  2. Stop smoking.
  3. Do not lose or gain everything in a short time.
  4. Avoid hypothermia, especially in the lower body.
  5. Time to treat cystitis, adnexitis and other diseases of the genitourinary system.
  6. Annually visit a gynecologist.
  7. Take contraceptive drugs only after consulting a doctor.