The causes of female infertility are hormonal imbalances and anovulation. How do hormones affect ovulation and pregnancy? Is it possible to get pregnant if you have thyroid disease?

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Before planning a child, a woman must determine optimal time conception. This period is ovulation, which increases the chance of fertilization several times. Often the egg does not mature and leave the follicle. This indicates hormonal disorders, which become an obstacle when planning a child. What hormone is responsible for ovulation and how to prevent disturbances in the body? The answers to these questions will be presented in the article.

Hormones responsible for ovulation

Several hormones are responsible for ovulation, each of which performs certain functions in the body. Their deficiency or excess negatively affects the possibility of conceiving a child.

Follicle stimulating hormone

It is produced by the pituitary gland and enters the body through nerve impulses. Synthesis of FSH occurs 1 time in 2-4 hours. The normal functioning of the ovaries depends on the amount of hormone produced. Under the influence of FSH, the amount of estrogen changes: the less the pituitary gland synthesizes follicle-stimulating hormone, the more intense the production of estrogen.

Phases menstrual cycle also associated with hormone synthesis. Before ovulation, the amount of estrogen in a woman's body is reduced. At the time of maturation of the egg, the pituitary gland begins to actively produce FGS, stimulating the thickening of the membranes of the reproductive organ. A sharp increase in FSH stimulates the release of mature cells from the follicle. The amount of FSH in a woman's body is constantly changing depending on the cycle.

Luteinizing hormone

Produced by the pituitary gland. LH is produced in the body of women and men. In the first case, he is responsible for ovulation. Only when normal level LH woman can become pregnant.

The hormone is responsible for the normal functioning of the reproductive system and regulates menstruation. Its indicator is constantly changing and depends on the cycle. Due to this, the female body forms monthly corpus luteum and the egg cell matures. LH also affects the production of other sex hormones - estrogen and progesterone. Without it, not only ovulation is impossible, but also conception itself.

Prolactin

The hormone is synthesized and produced in the brain. Together with lutein, it participates in the formation of the corpus luteum in the ovaries. Prolactin controls the production of progesterone, thereby influencing the maturation of the egg.

With the deviation of prolactin up or down, there is a violation of the functioning of the ovaries. This is manifested by the absence of ovulation and the inability to conceive a child. Women suffering from prolactin deficiency are more prone to spontaneous abortions and miscarriages.

Not all functions of prolactin have been studied by medicine. Perhaps in the future, doctors will be able to find out more information about the role of the hormone in the female body.

Estradiol

Under the influence of estradiol, a gradual change in the figure occurs in girls, the follicle grows and develops before ovulation. Without this component, the ovulation process will become impossible.

Estradiol prepares the genitals for pregnancy. For example, under its influence, the lining of the uterus thickens for better attachment of the embryo to its mucous structures. Due to estradiol, blood flow in the uterine area improves and its vessels dilate. During pregnancy, organs reproductive system change their structure thanks to estradiol.

Progesterone

Progesterone does not affect ovulation itself, but the further attachment of the fertilized egg to the mucous structures of the uterus. Therefore, progesterone is otherwise called the “pregnancy hormone”. In a woman’s body, it performs several important functions:

  • stimulates thickening of the walls of the reproductive organ during ovulation, thereby increasing the chance of successful egg transplantation;
  • responsible for the normal increase in size of the uterus during pregnancy;
  • relaxes the muscles of the uterus;
  • provides accumulation nutrients during pregnancy;
  • stimulates the growth of mammary glands;
  • inhibits milk production in the breast before the baby is born;
  • takes part in the formation of some embryonic tissues.

What will happen to ovulation if any hormone is too low or too high?

It is worth taking a closer look at how an increase or decrease in sex hormones affects ovulation.

  1. When follicle-stimulating hormone decreases, women are often diagnosed with infertility. The condition causes irregular cycles and pathological anovulation. In addition, the problem often indicates serious illness female reproductive system - polycystic disease. Pathology leads to the immaturity of the follicles in the ovary and increased production of estrogens. In this condition, ovulation, and accordingly, pregnancy becomes impossible. Lack of FSH causes cycle disruption, scanty menstruation, reduction in breast size. Sometimes women notice a deterioration in their health, complain of depression and a decrease in libido.
  2. A decrease in LH levels is diagnosed, as a rule, after the birth of a child. This is especially true when a woman is breastfeeding. Due to this, the formation of eggs in the genitals does not occur. In women who have not given birth to a child, this condition is considered abnormal and requires urgent drug therapy. In this case, drugs containing LH are prescribed in the required dosage. The products are available in the form of tablets or suppositories. Luteinizing hormone in increased quantity indicates the imminent onset of ovulation. In some cases, the increased value of this hormone in the body persists for about 3 days after the release of the egg from the follicle. The LH surge indicates possible gynecological problems– polycystic disease, endometriosis, slow ovarian function. These pathologies, in turn, cause the absence of ovulation or their irregular occurrence.
  3. A decrease in the hormone estradiol does not manifest itself with characteristic signs. The pathology becomes noticeable when a woman tries to get pregnant. The less estradiol the female body produces, the more testosterone (male hormone) it produces. This in turn leads to immaturity of the egg and disruption of follicle formation. An increase in estradiol is considered normal only during pregnancy. In this way, the body tries to preserve the fetus until labor occurs. In other cases, an overestimated value of this hormone is considered a pathology. The condition can be provoked by benign and cancerous tumors, pathologies of the endocrine system. All these problems lead to the impossibility of ovulation. An increase in the value of estradiol in the body often occurs with uncontrolled use of antifungal and anticonvulsants.
  4. Lack of progesterone is associated with inflammation of the genital organs or the formation of tumors in the ovaries. The condition can provoke long-term medication. Pathology primarily affects the regularity of the menstrual cycle and ovulation. Even if fertilization of the egg has occurred, if there is insufficient amount of the hormone in the female body, it will be difficult to attach the egg to the lining of the uterus. Problems also appear during pregnancy. Excess progesterone also negatively affects reproductive function. The condition is primarily associated with dysfunction of the thyroid gland and uncontrolled use medicines. These factors inhibit the maturation of the egg and its release from the follicle.

What drugs restore hormonal levels?

The treatment regimen depends on how many hormones require correction. A woman may be diagnosed with a deviation from the norm of one substance. But most often, when sexual dysfunction occurs, problems with several components are noted at once.

Treatment of pathology is carried out according to two schemes. In the first case, the struggle with the problem is carried out with oral contraceptives, in the second - with the use of individually prescribed means, that is, the lack or excess of each substance is controlled by a separate medication.

COC treatment is convenient because doctors do not need to select individual therapy tactics in each specific case. In contraceptives, hormone analogues are distributed according to the phases of the menstrual cycle.

It is much more difficult to create an individual treatment strategy. In this case, it becomes necessary to use several drugs. The gynecologist must select the medication in such a way as not to cause a deviation from the norm of other hormones. For example, to replenish the level of progesterone, women are prescribed Utrozhestan or Progesterone. The lack of estrogen is corrected with Premarin or Divigel. If there is an excess of this substance, Tamoxifen or Clomiphene is prescribed.

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Hormones during menstruation - series chemical elements in the female body, the development of which to the norm is necessary for the successful onset of pregnancy and the full bearing of the fetus. The duration of the menstrual cycle is 28 days, fluctuations from 21 to 35 days are possible. It is the duration of menstruation that is affected by the level of hormones, in girls it can reach up to 45 days.

A cycle is the period from last day menstruation and until the first day of the next menstruation. At the beginning of the cycle, the level of an important hormone for women, estrogen, increases, thanks to which the endometrium grows and thickens, strengthens pelvic bones The endometrium, lined around the uterus, nourishes the embryo, which is very important in the early stages of pregnancy.

In addition to the endometrium, a vesicle with follicles and an egg inside begins to grow. The release of the egg occurs just in the middle of the cycle on days 13–14, then it moves towards the sperm and into the uterine cavity. If the level of hormones is high, then the process of ovulation and embryo implantation occurs in the uterus. The highest probability of conception is 3-4 days after ovulation occurs when sexual intercourse takes place. Fertilization of the egg by sperm occurs. Otherwise inner layer The uterus is torn away, the death of the egg occurs, the level of hormones decreases and the next timely arrival of menstruation occurs.

Phases of the menstrual cycle

The cycle consists of several phases that replace one another at certain intervals: follicular, ovulation, luteal.

If ovulation has occurred, then after about 14 days, the release of gonadotropin begins, also stimulation further development corpus luteum. Under the influence of this body, progesterone is produced, which, in turn, prepares the uterus in pregnancy and further gestation of the fetus. During pregnancy, steroid hormones increase significantly in their levels.

How do hormones affect ovulation and pregnancy?

In these two very important processes for every woman, ovulation and conception, the hormones luteinizing, estradiol, prolactin, progesterone, testosterone, follicle-stimulating hormone are involved.


All hormones in combination are necessary for a woman to normal conception and the onset of pregnancy. When planning a pregnancy, women are advised to check their hormonal levels. If necessary, use drugs to increase (decrease) the level of certain hormones, also examine venous blood, her condition if she wants to have a baby. To calculate the amount of each of the described hormones, there are certain days when exactly you need to take into account their norm when planning a pregnancy.

FSH, normal

Follicle-stimulating hormone prepares a woman's body for pregnancy. Important hormone produced by the pituitary gland, hypothalamus and endocrine gland.

FSH is normally important in the first phase of the cycle, at the time of maturation of the egg in the ovarian follicles. The activation and effect of gonadotropic hormone on the follicles occurs before the onset of menstruation and in the first days. After 2-3 days, the growth of hormones stops, stimulation of the dominant follicle begins, inside which the egg is located.

The mature follicle, in turn, begins to produce estrogens, and the amount of steroids in the woman’s blood increases. The uterus quickly reacts to excess estrogen levels. The epithelium lining the inner layer of the mucosa begins to become thicker. With a layer thickness of 1 cm, the fertilized egg attaches to the wall of the uterus.

In addition to FSH, luteinizing hormone begins to be produced, preparing the body for conception. As a result of ovulation, when the egg matures and estradiol in the blood reaches maximum levels, the next stage towards conception begins.

An increase in the production of LH and FSH under the influence of the pituitary gland occurs in a matter of hours. A mature follicle ruptures, the egg is released and moves towards the uterus. The corpus luteum, formed at the site of the follicle, begins to produce progesterone. FSH decreases its values. LH continues to prepare the body for pregnancy.

FSH is the most unstable hormone. During the day it can change values ​​several times, especially in follicular phase. The menstrual cycle in girls, before puberty, has a great influence on the indicators. The indicators are the most stable - 0.11–1.6 IU ml.

During reproductive age, indicators are influenced by many various factors: day of the cycle, age, lifestyle, nutrition, chronic diseases.

Approximate hormone values ​​during the menstrual cycle

During menopause, the ovaries stop responding to FSH and LH, although their production by the pituitary gland continues. This explains sharp increase FSH levels increase in gonadotropic hormones. At this time, women feel unwell, their usual rhythm of life is disrupted.

FSH in deficiency or excess

An irregular cycle indicates that FSH in the blood is not normalized. If the hormone does not correspond to the norm, ovulation may not occur, spotting is scanty or, conversely, strong. This is what women often confuse when they are waiting for pregnancy. In case of shortage hormone FSH declines sharply sexual desire, the genitals and mammary glands atrophy. Pregnancy, as a rule, is absent and even when conception occurs, miscarriages are common. With an increase (decrease) in FSH, the hypothalamus may suffer, a tumor develops. Medicines can also affect hormone surges in the blood. Reason elevated values FSH hormone often leads to obesity and polycystic ovary syndrome.

The cause of low hormone levels:

  • menopause;
  • inflammation in the genitals;
  • cyst in the uterus;
  • dysfunction in the gonads;
  • alcohol abuse, smoking;
  • kidney diseases.

All reasons lead to a decrease in the likelihood of conception and normal pregnancy. An increase (decrease) in FSH greatly undermines women's health. Even if pregnancy occurs, the uterus will simply not be ready and miscarriages in the early stages are obvious. It is important to promptly eliminate the causes that led to FSH failure.

If the hormone deviates from the norm due to x-rays, special actions no need to take action. The level will return to normal approximately a year after irradiation.

It is important to avoid alcohol, which sharply exceeds gonadotropin levels in women. Tumors also require removal at the initial stage of development. Surgery is usually prescribed.

LH, features

It is the luteinizing hormone that influences the menstrual cycle and forms sex hormones in a woman’s body. In girls, LH levels are low. The increase begins at puberty, secrete gonadotropins necessary to stimulate the sex glands. Women need a hormone to stimulate the synthesis of estrogens, regulate the secretion of progesterone and form the corpus luteum.

Changes in LH concentration are observed throughout the entire menstrual cycle. The peak of the rise occurs in the middle of the cycle. LH rises above the level of FSH, a massive release occurs during the period of ovulation, a corpus luteum is formed, and progesterone is produced. When pregnancy occurs, LH levels decrease and estrogen concentrations increase.

An LH test is indicated for use when:


Diseases that lead to menstrual irregularities

Delays in menstruation, untimely arrival or absence of menstruation at all clearly indicate ailments, sometimes very serious ones, in the body. These are diseases of the thyroid gland, a tumor of the pituitary gland, problems with the adrenal glands, and ovaries. Possible development of cysts, chronic inflammation. All this leads to disruption of hormonal functions, an increase (decrease) in the level of certain hormones. As a result, it leads to absence of pregnancy, diseases of the uterus, and secondary infertility.

Ovulation does not occur with the remaining follicle in the ovary. Estrogen levels do not decrease. The endometrium begins to grow in the uterus. Sometimes there is no death of the body, which should be according to the physiological characteristics of the female body. Progesterone continues to be produced, endometrial rejection occurs with a delay.

Stress contributes to hormonal imbalance, especially if it occurs at the time of the menstrual cycle. A depressed state in women occurs not only against the background psychological changes, but also biochemical processes that are triggered before the onset of menstruation, causing an imbalance of hormones. A woman's tearfulness, irritability, and excessive fatigue increase.

Often, due to stress, a woman begins to gain weight. The level of sugar in the blood decreases, the hormone estradiol decreases, but energy is not added. After taking sweets or chocolate, the metabolism begins to break down, the woman quickly gains weight. All this indicates hormonal imbalances. Stress and mood swings during menstruation are caused by this factor. The body, in defense against stress, begins to produce the hormone cortisol, accumulating fat at the waist in reserve. With duration advanced level, the so-called stress hormone, begins to break down hormonal balance. Women need to see an endocrinologist to solve problems with overweight and treatment to stabilize hormone levels in the blood.

Hormone tests

Usually, tests are given after the expected ovulation, taking into account the menstrual cycle. If the discharge is smeared, then it is necessary to undergo a study on the level of FSH, progesterone, estradiol, prolactin testosterone, lutropin, androstenedione.

A blood test to determine the level of hormones in the blood is taken in the morning on an empty stomach. Physical exercise a few days before the test should be excluded.

The LH level is determined on days 6–7 of the cycle

Progesterone – on day 23

FSH – on days 3–7

Estradiol - on any day of the cycle.

The female body is fragile and should be taken care of from early childhood. Mom's girl should talk about what the reproductive system is, why it is needed, how it works, and what can happen as a result of its failure. Hygiene is also important for well-being, successful conception, bearing and birth of children in the future.

The body undergoes changes with age, and along with it, as the functions of the ovaries fade, the level of hormones begins to change. As a result, the production of FSH, LH, and testosterone stops. The endocrine system malfunctions and begins to produce hormones in small quantities.

Closer to 47 years old reproductive function begins to slowly fade away, menopause sometimes occurs in women much earlier. Planning a pregnancy is extremely important for women of reproductive age, as well as examining hormone levels and monitoring their condition at each stage of the menstrual cycle.

If the concentration of hormones increases or decreases, it is important to contact an endocrinologist and promptly correct the state of hormones, which directly affects the conception and bearing of a baby.

If symptoms of a malfunction appear, then it is necessary to take a blood test and test for hormones. It is important to normalize hormone levels and eliminate the causes that led to its failure. Restoring hormonal levels is difficult and time-consuming, taking months and even years. To stimulate their production, the attending physician will prescribe medication.

For preventive purposes, medical examinations and hormone tests should be regular. In the absence of treatment, breast cancer, infertility, obesity, etc. develop against the background of a malfunction. serious consequences. For every woman who wants to have children, maintaining normal hormones is extremely important.

D.R.A Medical Tel Aviv, Israel +972-77-4450480 contact(at)dramedical.com D.R.A Medical

D.R.A Medical - Treatment in Israel

Hormonal stimulation of the ovaries is one of the stages of preparation for the IVF procedure. The exception is IVF in natural cycle, although in this case, as a rule, hormonal preparations are prescribed - to prepare the endometrium for implantation of the embryo and to maintain a normal hormonal background.

Every month in the natural cycle, 1-2 follicles mature in a woman’s ovaries. This amount is not enough for the IVF procedure, therefore, before the oocyte puncture, the woman undergoes a course of hormone therapy, the purpose of which will be the maturation of several eggs at once. The more eggs you can get, the higher your chances of pregnancy. It is worth saying that hormonal induction of the ovaries can give rise to serious by-effect- ovarian hyperstimulation syndrome, but we will talk about this below.

How and what hormones control ovulation

In order to understand the principle of hormonal ovarian stimulation, consider how ovulation occurs in vivo.

The birth and development of the egg is controlled by two main hormones that are produced in the pituitary gland: luteinizing hormone and follicle-stimulating hormone. Under the influence of follicle-stimulating hormone in the follicular phase of the menstrual cycle (before ovulation), the ovarian follicle begins to grow and gradually reaches 2 cm in diameter. An egg develops inside the follicle. When the follicle matures, it releases estrogens - hormones that have a systemic effect, primarily on the woman’s reproductive organs. Under the influence of estrogens, the anterior lobe of the pituitary gland secretes an increased amount of luteinizing hormone (LH), which, reaching its maximum, triggers the “maturation” of the egg.
There is approximately 36-48 hours between the ovulatory LH peak and ovulation. If ovulation has taken place, the corpus luteum of the egg begins to produce the hormone progesterone, which is of great importance for embryo implantation and a successful pregnancy.

Hormonal stimulation before IVF involves artificial hormones and drugs that mimic their functions. For each natural hormone there are several analogues and in each case the use of a particular drug is determined by the decision of the attending physician and the patient's condition, so call trade marks There is no point in taking medications.

Before entering into an IVF protocol, a woman undergoes hormone tests; the results of these tests will determine the hormonal therapy regimen and dosage of medications.
The main list of hormones responsible for female reproductive health and involved in the IVF protocol is as follows: TSH (thyroid-stimulating hormone of the thyroid gland), estradiol, progesterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH).

Thyroid-stimulating hormone (TSH)- this hormone is produced by the thyroid gland and is responsible for the functioning of many systems, including the reproductive one. Deviations from the norm, both larger and smaller, cause various cycle disorders in a woman. TSH imbalances can manifest themselves in the form of conditions such as amenorrhea (cessation of menstruation), anovulatory cycles (when the egg is not released from the follicle), progesterone deficiency (in the absence of ovulation, the corpus luteum is not produced, and accordingly, progesterone is not produced), primary infertility. Data on the concentration of TSH in a woman’s blood is also important because this hormone affects the production of other thyroid hormones T3 and T4, which have a direct effect on conception and development of pregnancy. An imbalance of these hormones can lead to severe malformations of the fetus, the threat of termination of pregnancy or its complete impossibility. That is why, at the planning stage, it is necessary to take a TSH test (and then T3 and T4), so that if hormonal disorders are detected, they can be corrected and further complications can be avoided.

Follicle stimulating hormone (FSH)- a hormone of the anterior pituitary gland that has a direct effect on the functions of the gonads. FSH is involved in the development of follicles in the female ovaries and is involved in the creation of estrogens.
Its level changes during the menstrual cycle, reaching a maximum before ovulation. Determining the level of FSH in the blood plays a role important role when assessing female fertility. FSH is of great importance during IVF, because Based on its initial indicators, an ovarian stimulation protocol is selected.

Luteinizing hormone (LH) It is produced by the cells of the pituitary gland, under its action the synthesis of sex hormones occurs: estrogen, progesterone, testosterone. Reaching the maximum concentration of LH in the blood gives impetus to ovulation and stimulates the development of the corpus luteum, which produces progesterone. During hormonal induction, human chorionic gonadotropin is most often used to initiate egg maturation as a replacement for LH. If a woman is predisposed to ovarian hyperstimulation syndrome, gonadotropin agonists are used as a “trigger” of ovulation.

Estradiol- a hormone produced in the ovaries and adrenal glands, involved in the development of reproductive organs, as well as the onset of pregnancy naturally or as a result of IVF. Estradiol during IVF is responsible for providing the conditions necessary for favorable implantation of the embryo in the uterine cavity.
Based on the concentration of estradiol in the blood, the approximate number of maturing follicles can be determined. Its level doubles every 48 hours.

Progesterone- a key hormone for all processes associated with pregnancy planning, its course and subsequent breastfeeding. It is not for nothing that it is also called the “pregnancy hormone”. In non-pregnant women it is produced by the corpus luteum of the follicle, and during pregnancy by the placenta.
The main function of progesterone is to prepare the female body for reproduction: it is responsible for the necessary changes in the uterus associated with preparation for possible conception and gestation, thanks to which the placenta is formed. During IVF, the level of progesterone in the blood is critical important, since the success of subsequent implantation largely depends on the concentration of this hormone in the blood.

The state of the female reproductive system depends on the balance of the concentration of all these hormones. A skew in any direction of any component will cause an imbalance of the entire system, which means there will be difficulties with conception and pregnancy. Therefore, in order to minimize risks, hormonal stimulation temporarily “turns off” the production of some of its hormones and the woman receives again those doses of hormones that will be optimal in her particular case.

Want to make sure you and your partner are ready for IVF?
​Download a simple and convenient form containing a list and description of all tests necessary for IVF - Checklist of preliminary tests for IVF

What is an IVF protocol

The schedule for taking hormonal drugs, scheduled by day and hour, is called an IVF protocol. There are several protocol options - short, long, ultra-short, ultra-long, French, Japanese, cryoprotocol and others.

Choosing the right protocol is one of the key factors for the success of the entire IVF procedure. This choice depends on the patient’s hormonal status, her health characteristics, and past experience in the field of reproduction.
The principle of operation of all IVF protocols is generally the same and has one goal - the maturation of the optimal number of follicles in the ovaries. The difference will be in the number of days of taking hormonal drugs and their sequence. It goes without saying that the list of these drugs and their doses will also differ. Therefore, there is no point in asking friends what drug regimen was prescribed for them; it will still be different for each patient.

Long and short IVF protocols

These two schemes are most often used. Other protocols are also being developed based on them.
The long protocol is indicated for women with average ovarian reserve, endometrial problems, ovarian cysts, and fibroids. It begins on days 21-22 of the previous cycle with the use of drugs that suppress the production of one’s own hormones FSH and LH. This is done to ensure that follicle maturation and ovulation occur in needed by the doctor a moment strictly under his control. While taking these drugs, ovarian stimulation begins from day 2-3 of the new cycle, and taking stimulating drugs lasts 10-12 days. Hormonal drugs in IVF protocols, the production of two hormones is stimulated: FSH and LH. IN normal cycle non-dominant follicles die before ovulation occurs as FSH levels drop. FSH injections keep it at a high level, so the ovaries produce several eggs at once.

When the follicles reach the desired size, a drug is administered, the principle of which is similar to natural LH, to start the process of egg maturation. This drug is administered in such a way that the process of egg maturation is started, and ovulation has not yet occurred, since the collection of eggs must be done before the egg leaves the follicle. After which it becomes possible to successfully puncture the follicle and “get” the egg.
The short protocol is more stringent in terms of timing; it is clearly tied to the woman’s menstrual cycle. Stimulating therapy should begin no later than day 2 of the cycle. In the short protocol, ovarian stimulation is carried out over 10 days. Once the follicles reach the desired size, a “trigger” drug is prescribed to trigger ovulation. Most often this is a large dose of human hormone human chorionic gonadotropin(hCG), which starts the process of maturation of several follicles at once. The main condition for prescribing hCG is the presence of several follicles of the required size. In addition, the concentration of estradiol must be at a sufficient level. After 35 hours, the follicles are punctured.
In place of the punctured follicles, corpus luteum is formed, which produces progesterone, the task of which is to prepare the uterine mucosa for implantation of the embryo. In stimulated cycles, estradiol levels are higher than progesterone levels, so additional doses of progesterone are administered to restore the balance of estrogen and progesterone.

During stimulation, the woman donates blood several times for hormones and does an ultrasound so that the doctor can understand how the body responds to the hormones. hormone therapy and is everything going according to plan?

Advantages and disadvantages of long and short IVF protocols


The advantage of a long protocol is its manageability and flexibility: stimulating therapy can be started from days 2-6 of the new cycle. You can also shift the date of follicle puncture by 1-2 days, if necessary. When using a long protocol, doctors achieve maturation larger number eggs of the same quality and size, but this is its downside - it can lead to ovarian hyperstimulation syndrome, so women prone to this complication are not prescribed a long protocol.

What is ovarian hyperstimulation syndrome
A powerful attack on the female body with large doses of hormones carries a heavy load. Speaking about hormonal stimulation before IVF, one cannot help but mention such a serious complication as ovarian hyperstimulation syndrome. It occurs most often in long IVF protocols in women with a rich ovarian reserve. It is associated with the formation of a large number of follicles - 15 on each side. An increase in the number of follicles increases the concentration of estrogen in the blood, as well as the content of vasomotor substances, which affect the walls of blood vessels throughout the body. As a result, fluid leaks from the vessels and accumulates in the abdominal cavity and pericardium. Lack of fluid in the vascular bed disrupts the activity of the brain, kidneys and other vital functions. important organs. This is a serious complication, and the attending physician must consider all possible risks when choosing a stimulation protocol.

The advantage of the short protocol is the possibility of prescribing a gonadotropin agonist drug (not hCG) as a “trigger” to reduce the risk of developing ovarian hyperstimulation syndrome to zero. The use of these drugs, however, also reduces the chances of pregnancy. In such cases, segmented protocols are used, when stimulation is performed in one cycle and embryo transfer in the next.

Each protocol has its pros and cons; if one does not work in one cycle, the next time the doctor may suggest a different regimen and the body’s response may change dramatically. In general, they all pursue the same goals and are approximately equal in efficiency and cost.

An egg that has matured in the follicle, ready for fertilization, destroys the surface of the ovary and passes through abdominal cavity into the fallopian tube. This phenomenon is called ovulation. It occurs in the middle of a woman’s menstrual period, but can shift in one direction or another, occurring on the 11th – 21st days of the cycle.

Menstrual cycle

In a female fetus at 20 weeks prenatal development there are already 2 million immature eggs in the ovaries. 75% of them disappear soon after the girl is born. Most women have reproductive age 500 thousand eggs are stored. By the beginning of puberty, they are ready for cyclical maturation.

During the first two years after menarche, anovulatory cycles are common. Then the regularity of the maturation of the follicle, the release of the egg and the formation of the corpus luteum is established - the ovulation cycle. A disruption in the rhythm of this process occurs during menopause, when the release of an egg occurs less and less and then stops.

When an egg moves into the fallopian tube, it can merge with a sperm - fertilization. The resulting embryo enters the uterus. During ovulation, the uterine walls thicken and the endometrium grows, preparing for implantation of the embryo. If conception does not occur, the inner layer of the uterine wall is rejected - menstrual bleeding occurs.

On what day after menstruation does ovulation occur?

Normally, this is the middle of the cycle, taking into account the first day of menstruation. For example, if 26 days pass between the first days of each menstruation, then ovulation will occur on the 12th – 13th day, taking into account the day the period begins.

How many days does this process take?

The release of a mature germ cell occurs quickly, hormonal changes in this case, they are registered within 1 day.

One of the misconceptions is to believe that if you have periods, then the cycle was necessarily ovulatory. Thickening of the endometrium is controlled by estrogen, and ovulation is caused by the action of follicle-stimulating hormone (FSH). Not every menstrual cycle is accompanied by the process of ovulation. Therefore, when planning pregnancy, it is recommended to monitor the precursors of egg release and use additional tests to determine it. If anovulation lasts for a long time, you should consult a gynecologist.

Hormonal regulation

Ovulation occurs under the influence of FSH, which is synthesized in the anterior lobe of the pituitary gland under the influence of regulators formed in the hypothalamus. Under the influence of FSH, the follicular phase of egg maturation begins. At this time, one of the follicle vesicles becomes dominant. As it increases, it reaches the preovulatory stage. At the moment of ovulation, the wall of the follicle ruptures, the mature reproductive cell contained in it leaves the ovary and penetrates the uterine tube.

What happens after ovulation?

The second phase of the cycle begins - the luteal phase. Under the influence of the luteinizing hormone of the pituitary gland, a unique endocrine organ, the corpus luteum, appears at the site of the ruptured follicle. This is a small round formation yellow color. The corpus luteum secretes hormones that cause the endometrium to thicken and prepare it for implantation of the embryo during pregnancy.

Anovulatory cycle

Menstrual-like bleeding may recur regularly after 24-28 days, but the egg does not leave the ovary. This cycle is called . In the absence of ovulation, one or more follicles reach the preovulatory stage, that is, they grow, and a germ cell develops inside. However, the follicular wall does not rupture and the egg does not come out.

Soon after this, the mature follicle undergoes atresia, that is, reverse development. At this time, estrogen levels decrease, which leads to menstrual-like bleeding. By external signs it is practically indistinguishable from normal menstruation.

Why is there no ovulation?

It could be physiological state during puberty or premenopause. If a woman is in childbearing age, rare anovulatory cycles – normal phenomenon.

Many hormonal disorders lead to an imbalance of the “hypothalamus-pituitary-ovary” system and change the timing of ovulation, in particular:

  • hypothyroidism (lack of thyroid hormones);
  • hyperthyroidism (excess thyroid hormones);
  • hormonally active benign tumor pituitary gland (adenoma);
  • adrenal insufficiency.

Emotional stress can prolong the ovulatory period. It leads to a decrease in the level of gonadotropin-releasing factor, a substance secreted by the hypothalamus and stimulating the synthesis of FSH in the pituitary gland.

Other possible reasons for which there is a lack or delay of ovulation associated with hormonal imbalance:

  • intense sports and physical activity;
  • rapid weight loss of at least 10%;
  • chemotherapy and radiation for malignant neoplasms;
  • taking tranquilizers, corticosteroid hormones and some contraceptives.

The main physiological reasons for the absence of ovulation are pregnancy and menopause. During premenopause, women may continue to have more or less regular periods, but the likelihood of anovulatory cycles increases significantly.

Symptoms of egg release

Not all women experience signs of ovulation. At this moment, hormonal changes occur in the body. By carefully observing your body, you can discover the period of best fertilization ability. It is not necessary to use complex and expensive methods for predicting egg release. It is enough to detect natural symptoms in time.

  • Change in cervical mucus

The female body prepares for possible conception by producing cervical fluid, suitable for the transfer of sperm from the vagina to the uterine cavity. Until ovulation, this discharge is thick and viscous. They prevent sperm from entering the uterus. Before ovulation glands cervical canal begin to produce a special protein - its threads are thin, elastic and similar in properties to the protein of a chicken egg. Vaginal discharge become transparent and stretch well. This environment is ideal for sperm to penetrate into the uterus.

  • Change in vaginal moisture

Discharge from the cervix becomes more abundant. During sexual intercourse, the amount of vaginal fluid increases. A woman feels increased humidity throughout the day, which shows her readiness for fertilization.

  • Breast tenderness

After ovulation, progesterone levels increase. If a woman keeps a chart, she will see that her basal temperature has risen. It is caused precisely by the action of progesterone. This hormone also affects the mammary glands, so at this point they become more sensitive. Sometimes this soreness resembles premenstrual sensations.

  • Changing the position of the cervix

After the end of menstruation, the cervix is ​​closed and low. As ovulation approaches, it rises higher and softens. You can check this yourself. After washing your hands thoroughly, you need to put your foot on the edge of the toilet or bathroom and insert two fingers into the vagina. If you have to push them deep, it means your cervix has risen. It is easiest to check this symptom immediately after menstruation, in order to better determine the change in the position of the cervix.

  • Increased sex drive

Women often notice a stronger sex drive mid-cycle. These sensations during ovulation are of natural origin and are associated with changes in hormonal levels.

  • Bloody issues

Sometimes in the middle of the cycle there are small spotting from the vagina. It can be assumed that these are the "remnants" of blood leaving the uterus after menstruation. However, if this sign appears during the expected ovulation, it indicates a rupture of the follicle. In addition, some blood can also be released from the endometrial tissue under the influence of hormones immediately before or after ovulation. This symptom indicates high fertility.

  • Cramp or pain on one side of the abdomen

20% of women experience pain during ovulation, which is called pain. It occurs when the follicle ruptures and the fallopian tube contracts as the egg moves into the uterus. A woman feels pain or spasm on one side of her lower abdomen. These sensations after ovulation do not last long, but serve as a fairly accurate sign of the ability to fertilize.

  • Flatulence

Hormonal shifts cause slight bloating. It can be detected by clothing or a belt that has become a little tight.

  • Mild nausea

Hormonal changes can cause mild nausea, similar to pregnancy.

  • Headache

In 20% of women, before or during menstruation, headache or migraine. The same symptom in these patients may accompany the onset of ovulation.

Diagnostics

Many women are planning their pregnancy. Conceiving after ovulation gives the greatest chance of fertilization of the egg. Therefore, they use additional methods to diagnose this condition.

Tests functional diagnostics during the ovulatory cycle:

  • basal temperature;
  • pupil symptom;
  • study of cervical mucus extensibility;
  • karyopyknotic index.

These studies are objective, that is, quite accurately and regardless of the sensations of a woman, they show the phase of the ovulatory cycle. They are used when normal hormonal processes are disrupted. With their help, for example, ovulation is diagnosed when irregular cycle.

Basal temperature

Measurements are carried out by placing a thermometer in the anus by 3-4 cm, immediately after waking up. It is important to perform the procedure at the same time (a half hour difference is acceptable), after at least 4 hours of continuous sleep. You need to take your temperature every day, including on menstruation days.

The thermometer should be prepared in the evening so as not to shake in the morning. In general, it is not recommended to make unnecessary movements. If a woman uses mercury thermometer, after it is inserted into the rectum, she should lie still for 5 minutes. It is more convenient to use an electronic thermometer, which will beep when the measurement is completed. However, sometimes such devices give erroneous readings, which can lead to incorrect detection of ovulation.

After the measurement, the result must be plotted on a graph, divided by vertical axis by tenths of a degree (36.1 – 36.2 – 36.3 and so on).

In the follicular phase, the temperature is 36.6-36.8 degrees. Starting from the second day after ovulation, it rises to 37.1-37.3 degrees. This rise is clearly visible on the chart. Just before the release of the egg, the mature follicle secretes maximum amount estrogen, and on the graph this may appear as a sudden decrease (“recession”), followed by a rise in temperature. It is not always possible to register this sign.

If a woman irregular ovulation, constant measurement rectal temperature will help her determine the most favorable day for conception. The accuracy of the method is 95%, subject to the rules for performing measurements and interpreting the results by a doctor.

Pupil symptom

This sign is detected by a gynecologist when examining the cervix using vaginal speculum. During the follicular phase of the cycle, the external uterine os gradually increases in diameter, and the cervical discharge becomes more and more transparent (+). Outwardly, it resembles the pupil of an eye. By the time of ovulation, the uterine os is maximally dilated, its diameter reaches 3-4 cm, the pupil symptom is most pronounced (+++). On days 6-8 after this, the external opening of the cervical canal closes, the pupil symptom becomes negative (-). The accuracy of this method is 60%.

Extensibility of cervical mucus

This sign, which can be noticed independently, is quantified using a forceps (a type of tweezers with teeth on the edges). The doctor grabs mucus from the cervical canal, stretches it and determines the maximum length of the resulting thread.

In the first phase of the cycle, the length of such a thread is 2-4 cm. 2 days before ovulation it increases to 8-12 cm, starting from the 2nd day after it decreases to 4 cm. From the 6th day the mucus practically does not stretch. The accuracy of this method is 60%.

Karyopyknotic index

This is the ratio of cells with a pyknotic nucleus to total number superficial epithelial cells in a vaginal smear. Pyknotic nuclei are wrinkled and less than 6 µm in size. In the first phase, their number is 20-70%, 2 days before ovulation and at the time of its onset - 80-88%, 2 days after the release of the egg - 60-40%, then their number decreases to 20-30%. The accuracy of the method does not exceed 50%.

More exact method determination of ovulation - hormonal studies. The disadvantage of this method is the difficulty of using it with an irregular cycle. The level of luteinizing hormone (LH), estradiol, and progesterone is determined. Typically, such tests are prescribed without taking into account individual characteristics, on the 5th – 7th and 18th – 22nd days of the cycle. Ovulation does not always occur during this period, with more long cycle it happens later. This leads to unfounded diagnosis of anovulation, unnecessary tests and treatment.

The same difficulties arise when using drugs that are based on changes in the level of LH in the urine. A woman must either accurately guess the time of ovulation, or constantly use rather expensive test strips. There are reusable test systems that analyze changes in saliva. They are quite accurate and convenient, but the disadvantage of such devices is their high cost.

LH levels may be persistently elevated in the following cases:

  • severe stress due to the desire to become pregnant;

Ultrasound detection of ovulation

The most accurate and cost-effective method is diagnosing ovulation using ultrasound (). With ultrasound monitoring, the doctor evaluates the thickness of the endometrium, the size of the dominant follicle and the corpus luteum formed in its place. The date of the first study depends on the regularity of the cycle. If it has the same duration, the study is carried out 16-18 days before the start date of menstruation. If the cycle is irregular, an ultrasound scan is prescribed on the 10th day from the beginning of menstruation.

At the first ultrasound, the dominant follicle is clearly visible, from which a mature egg will subsequently be released. By measuring its diameter, you can determine the date of ovulation. The size of the follicle before ovulation is 20-24 mm, and its growth rate in the first phase of the cycle is 2 mm per day.

A second ultrasound is prescribed after the expected date of ovulation, when a corpus luteum is detected at the site of the follicle. At the same time, a blood test is performed to determine progesterone levels. The combination of increased progesterone concentration and the presence of a corpus luteum on ultrasound confirms ovulation. Thus, a woman undergoes only one test for hormone levels per cycle, which reduces her financial and time costs for the examination.

When examining in the second phase, changes in the corpus luteum and endometrium can be detected, which can prevent pregnancy.

Ultrasound monitoring confirms or denies ovulation even in cases where data from other methods turned out to be uninformative:

  • an increase in basal temperature in the second phase due to a decrease in the production of hormones by the atretic follicle;
  • increased basal temperature and progesterone levels with low endometrial thickness, which prevents pregnancy;
  • no changes in basal temperature;
  • false positive ovulation test.

An ultrasound examination helps answer many of a woman’s questions:

  • does she ever ovulate?
  • whether it will happen in the current cycle or not;
  • On what day will the egg be released?

Changes in the timing of ovulation

The release time of the egg may vary by 1-2 days even with a regular cycle. Permanently shortened follicular phase and early ovulation may lead to problems with conception.

Early ovulation

If the release of the egg occurs 12-14 days after the start of menstruation, there is no reason to worry. However, if the basal temperature chart or test strips show that this process occurred on the 11th day or earlier, then the released egg is not developed enough for fertilization. At the same time, the mucus plug in the cervix is ​​quite dense, and sperm cannot penetrate through it. Insufficient increase in endometrial thickness, caused by a reduction in the hormonal influence of estrogens in the developing follicle, prevents implantation of the embryo, even if fertilization has occurred.

Still being studied. Sometimes it happens accidentally, in one of the menstrual cycles. In other cases, pathology may be caused by the following factors:

  • severe stress and disruption of the relationship between the hypothalamus and pituitary gland in the nervous system, which leads to a sudden premature increase in LH levels;
  • the natural aging process, when to maintain the maturation of the egg, the body produces more FSH, which causes excessively rapid growth of the follicle;
  • smoking, overuse alcohol and caffeine;
  • gynecological and endocrine diseases.

Can ovulation occur immediately after menstruation?

This is possible in two cases:

  • if menstruation lasts 5-7 days, and against this background it occurs hormonal disbalance, early ovulation can occur almost immediately after their completion;
  • if two follicles mature at different times in different ovaries, then their cycles do not coincide; in this case, ovulation of the second follicle is timely, but occurs in the first phase in the other ovary; This is associated with cases of pregnancy during sexual intercourse during menstruation.

Late ovulation

For some women from time to time ovulatory phase occurs on the 20th day of the cycle and later. Most often this is caused hormonal disorders in a complex balanced system “hypothalamus - pituitary gland - ovary”. Usually these changes are preceded by, caused by stress or taking certain medicines(corticosteroids, antidepressants, antitumor drugs). increases the risk chromosomal disorders in the egg, fetal malformations and early termination of pregnancy.

If two follicles in each ovary do not mature at the same time, ovulation is possible before menstruation.

The cause of such a failure may be breastfeeding. Even if a woman regains her period after childbirth, she experiences a long follicular phase or anovulatory cycles for six months. This normal process, laid down by nature and protects a woman from re-pregnancy.

During breastfeeding, both menstruation and ovulation are often absent for some time. But at a certain moment, the maturation of the egg begins, it is released, and it enters the uterus. And only 2 weeks after this, menstruation begins. This is how ovulation is possible without menstruation.

Often late ovulation happens too thin women or patients who have rapidly lost weight. The amount of fat in the body is directly related to the level of sex hormones (estrogens), and a small amount of it leads to delayed egg maturation.

Treatment for ovulatory cycle disorders

Anovulation for several cycles throughout the year is normal. But what to do if there is no ovulation all the time, and a woman wants to get pregnant? You should be patient, find a qualified gynecologist and contact him for diagnosis and treatment.

Reception oral contraceptives

Usually, a course of oral contraceptives is first recommended to cause the so-called rebound effect - ovulation after discontinuation of OCs is likely to occur in the first cycle. This effect persists for 3 consecutive cycles.

If a woman has taken these medications before, they are discontinued and ovulation is expected to resume. On average, this period takes from 6 months to 2 years, depending on the duration of taking birth control pills. Conventionally, it is believed that for every year of using oral contraceptives, 3 months are required to restore ovulation.

Stimulation

In more severe cases, after excluding diseases of the thyroid gland, adrenal glands, pituitary tumors and other possible “external” causes of anovulation, the gynecologist will prescribe medications for. At the same time, he will monitor the patient’s condition, conduct ultrasound monitoring of the follicle and endometrium, and prescribe hormonal tests.

If there has been no period for 40 days or more, pregnancy is first ruled out, and then progesterone is administered to induce menstrual-like bleeding. After an ultrasound and other diagnostics, medications for ovulation are prescribed:

  • clomiphene citrate (Clomid) is an anti-estrogenic ovulation stimulator that increases the production of FSH in the pituitary gland, its effectiveness is 85%;
  • gonadotropic hormones (Repronex, Follistim and others) are analogues of one’s own FSH, causing the egg to mature, their effectiveness reaches 100%, but they are dangerous for the development of ovarian hyperstimulation syndrome;
  • hCG, often used before the IVF procedure; HCG is prescribed after the release of the egg to maintain the corpus luteum, and subsequently the placenta, and maintain pregnancy;
  • leuprorelin (Lupron) is an analogue of gonadotropin-releasing factor, which is produced in the hypothalamus and stimulates the synthesis of FSH in the pituitary gland; this drug does not cause ovarian hyperstimulation syndrome;

Self-medication with these drugs is prohibited. When strictly following the doctor's recommendations and treatment in accordance with internationally recognized rules, most women manage to become pregnant in the first 2 years after starting therapy.

Auxiliary reproductive technologies

In the event that ovulation disorders cannot be corrected, assisted reproductive technologies come to the woman’s aid. However, they are associated with strong hormonal influence on the body to obtain a normal mature egg. Are used complex circuits medications. Such procedures should only be performed in specialized medical centers.

The reproductive function of women is carried out primarily due to the activity of the ovaries and uterus, because the egg matures in the ovaries, and in the uterus, under the influence of hormones secreted by the ovaries, changes occur in preparation for the reception of a fertilized ovum. The reproductive period is characterized by the ability of a woman’s body to reproduce offspring; The duration of this period is from 17-18 to 45-50 years. The reproductive period is preceded by the following stages: intrauterine; newborns (up to one year); childhood (8-10 years); prepubertal and pubertal age (17-18 years). The reproductive period transitions into menopause, in which premenopause, menopause and postmenopause are distinguished.

Menstrual cycle- one of the manifestations of complex biological processes in a woman's body. The menstrual cycle is characterized by cyclic changes in all parts of the reproductive system, external manifestation which is menstruation. Menstruation is bloody discharge from a woman’s genital tract that periodically occurs as a result of the rejection of the functional layer of the endometrium at the end of a two-phase menstrual cycle. The first menstruation occurs at the age of 12-13 years, for a year after this menstruation may be irregular, and then a regular menstrual cycle is established. The first day of menstruation is the first day of the menstrual cycle. The duration of the cycle is the time between the first two days of the next two periods. Average duration The menstrual cycle ranges from 21 to 35 days. The amount of blood loss in menstrual days 40 – 60 ml. The duration of normal menstruation is from 2 to 7 days. During the menstrual cycle, follicles grow in the ovaries and the egg matures, which as a result becomes ready for fertilization. At the same time, sex hormones are produced in the ovaries, which provide changes in the uterine mucosa. Sex hormones (estrogens, progesterone, androgens) are steroids and affect target tissues and organs. These include the reproductive organs, primarily the uterus, mammary glands, spongy bone, brain, endothelium and vascular smooth muscle cells, myocardium, skin and its appendages.

Estrogens contribute to the formation of genital organs, the development of secondary sexual characteristics during puberty. Androgens influence the appearance of pubic hair and armpits. Progesterone controls the secretory phase of the menstrual cycle, prepares the endometrium for implantation. Cyclic changes in the ovaries include three main processes:

    Growth of follicles and formation of a dominant follicle.

    Ovulation.

    Education, development and regression of the corpus luteum.

It is customary to distinguish the following main stages of follicle development:

    primordial follicle,

    preantral follicle,

    antral follicle,

    preovulatory follicle.

Primordial The follicle consists of an immature egg, which is located in the follicular and granular epithelium. Outside, the follicle is surrounded by a connective membrane. During each menstrual cycle, from 3 to 30 primordial follicles begin to grow, from which preantral, or primary follicles are formed.

Preantral follicle. As growth begins, the primordial follicle progresses to the preantral stage and the oocyte enlarges and is surrounded by a membrane called the zona pellucida. Granulomatous epithelial cells undergo proliferation. This growth is characterized by an increase in estrogen production.

Antral, or secondary follicle. It is characterized by further growth: the number of cells of the granulosa layer, producing follicular fluid, increases. During the period of folliculogenesis (8-9 days of the menstrual cycle), the synthesis of sex steroid hormones is noted. One dominant follicle is formed from many antral follicles (by the 8th day of the cycle). It is the largest and contains the largest number of cells of the granulosa layer. Along with the growth and development of the dominant preovulatory follicle in the ovaries, the process of atresia of the remaining growing follicles occurs in parallel.

Ovulation– rupture of the preovulatory dominant follicle and release of the egg from it. By the time of ovulation, the process of meiosis occurs in the oocyte. Ovulation is accompanied by bleeding from the destroyed capillaries surrounding the connective membrane. After the release of the egg, the resulting capillaries quickly grow into the cavity of the follicle. Granulosa cells undergo luteinization: the volume of their cytoplasm increases and lipid inclusions form. This process leads to the formation of the corpus luteum.

corpus luteum– a transient endocrine gland that functions for 14 days, regardless of the duration of the menstrual cycle. In the absence of pregnancy, the corpus luteum regresses.

Regulation of the menstrual cycle

Regulation of the menstrual cycle is complex and multicomponent, carried out with the participation of the mediobasal (pituitary) zone of the hypothalamus, the anterior lobe of the pituitary gland and the ovaries, the hormones of which (estrogens and progesterone) cause cyclic changes in the target organs of the reproductive system, primarily in the uterus. Physiological rhythmic processes in the hypothalamus and pituitary gland, accompanied by fluctuations in the secretion of gonadotropic hormones, lead to cyclic changes in the ovaries.

First(follicular) phase in the ovaries, the growth and maturation of follicles occurs, one of which (dominant, or leading) reaches the preovulatory stage.

In the middle During menstruation, this follicle bursts and a mature egg enters the abdominal cavity (ovulation).

After ovulation comes second (luteal) phase menstrual cycle, during which a corpus luteum forms at the site of the burst follicle.

By the end of the menstrual cycle, if fertilization has not occurred, corpus luteum regresses. In connection with these processes, the secretion of estrogen and progesterone changes cyclically.

The secretion of hormones by the glands is controlled by the nervous system, which, in turn, is influenced by the hormonal state of the body. Thus, we can talk about a single complex – the neuroendocrine system. In this system, there is a clear vertical subordination of some glands to others. The hypothalamus is considered the central endocrine gland: it receives signals from nervous system, according to which super-hormones are produced - releasing factors, that is, substances that stimulate the production of hormones by other glands. In relation to the reproductive system, subordination looks like this: hypothalamus – adrenal glands – ovaries, further impact on hormonal-dependent organs. At the same time, there is a feedback in the system: for example, an increase in the level of estrogens produced in the ovaries leads to the release of a releasing factor by the hypothalamus, which ultimately inhibits the production of estrogens. If a woman has had one ovary removed, sharp decline Hormone levels cause the hypothalamus to stimulate the remaining ovary, causing it to enlarge. The ovaries produce 3 types of hormones:

    estrogens (estradiol, estrone, estriol),

    gestagens (progesterone, 17-alpha-hydroxyprogesterone),

    androgens (androstenediol, dehydroepiandrosterone).

Estrogens are produced by the cells that make up the wall of the follicle, inside which the egg is formed. Therefore, if at the beginning of the cycle about 200 micrograms of estrogens are released per day, then by the time of ovulation (egg maturation), their level reaches 500 micrograms per day. Estrogens act on target organs, the cells of which retain these hormones. The cells of other organs do not seem to “notice” estrogens. Target organs for estrogens are the uterus, vagina, the ovaries themselves, and the mammary glands. The effect of estrogens on the genitals depends on the dose of the hormone. Small and medium doses stimulate the development of the ovaries and the maturation of follicles, large doses inhibit the maturation of the egg, very large doses cause atrophy (shrinkage and shrinkage) of the ovaries. In the uterus, under the influence of estrogen, the formation of muscle fibers and muscle tone increases. Very large and long-term doses of estrogen can lead to the formation of uterine fibroids. Estrogens also cause the lining of the uterus, the endometrium, to grow. However, large doses of estrogen can lead to the formation of polyps and bleeding. The normal level of estrogen promotes the development of the vagina and improves the condition of its mucous membrane. Estrogens act on the ovaries directly and indirectly through the pituitary gland. Thus, small doses of estrogens produced before puberty stimulate the development of follicles, from which eggs will subsequently appear. But the most interesting mechanism of action of estrogens on the ovaries occurs through the pituitary gland - such a developed self-regulatory system that it is very problematic to disrupt it: Small doses of estrogens stimulate the production of FSH (follicle-stimulating hormone), under the influence of which the follicle develops, in the wall of which estrogens are produced. But the entry of large doses of estrogen into the blood blocks the production of FSH. In the mammary glands, estrogens stimulate the development of the entire duct system, the size and color of the nipples and areolas. Estrogens affect the entire metabolism - glucose, microelements, macroergic compounds in muscles, fatty acids, and also reduce cholesterol levels. In area mineral metabolism estrogens most pronounced effect on the delay in the body of sodium, calcium and extracellular water, iron and copper. All these features of the exchange lead to the formation of a feminine figure with a peculiar distribution of adipose tissue. The action of estrogens on the genitals is manifested only in the presence of folic acid.

Gestagens are produced mainly by cells of the corpus luteum, which is formed at the site of a burst follicle. Progesterone acts on the same target organs as estrogens, and in most cases only after they have been affected by estrogens. Progesterone regulates the possibility of conception, helping to maintain the viability of the egg, moving it through the tubes, causing favorable changes in the uterine mucosa, where the fertilized egg is attached. Progesterone is absolutely necessary for the development and maintenance of pregnancy; under its action, the walls of the uterus thicken, its contractions are blocked, the cervix is ​​strengthened, and the activity of the mammary glands is stimulated. Acting on the brain indirect way suppresses LH secretion (negative feedback). Like estrogen, it also suppresses the secretion of FSH. The release of progesterone is accompanied by an increase in temperature immediately after ovulation. Finally, as with estrogens, progesterone levels regulate the activity of the pituitary gland using a feedback principle. The effect of progesterone on general exchange substances depend on the level of the hormone: small doses inhibit the excretion of sodium, chlorine and water, and large doses increase the excretion of urine. In addition, it enhances metabolism, especially due to amines and amino acids. The action of progesterone on thermoregulatory centers underlies known method monitoring ovarian activity by measuring basal (rectal) temperature.

Androgens are formed in the ovaries in specific follicle cells, as well as in the adrenal glands. The effect of androgens on the genitals is twofold: small doses cause proliferation of the uterine mucosa (in large doses - the formation of polyps and cysts), and with low estrogen content they cause atrophy of the mucosa. Besides, long-term use large doses of androgens cause an enlargement of the clitoris and labia majora, and the labia minora, on the contrary, sharply decrease. Small doses of androgens stimulate the activity of the ovaries, and large doses inhibit them. In addition to the listed hormones, the activity of the ovaries, the menstrual cycle and the possibility of pregnancy are influenced by GONADOTROPIC hormones produced in the pituitary gland. This follicle-stimulating (FSH), luteinizing (LH) and luteotropic (LTG) hormones. All of them act sequentially, as if transferring to each other control over the development of the follicle, the maturation of the egg, and the formation of the corpus luteum. So, FSH on early stages The menstrual cycle causes the egg to grow, but in order for it to fully mature, the additional influence of LH is necessary. Under the combined influence of these hormones, the egg matures, leaves the follicle, leaving in its place the so-called corpus luteum - a temporary endocrine gland, producing progesterone, which is mentioned above. The level of LTG secretion determines how much progesterone there will be, and therefore, how firmly the egg will stay in the uterus. In addition, LTG regulates milk production after childbirth. As already mentioned, the production of ovarian and gonadotropic hormones occurs within the framework of feedback: an increase in the level of some hormones leads to a decrease in the level of others, which automatically increases the secretion of the first again, etc.

The course of the MENSTRUAL CYCLE can be schematically depicted as follows. The hypothalamus produces FSH-releasing factor, which stimulates the production of FSH in the pituitary gland. FSH causes follicle growth and development. Estrogens are produced in the follicle, which stimulate the release of LH. LH and FSH together cause follicle growth until almost ovulation of the egg. Estrogens, together with a small amount of progesterone, stimulate the release of LH-releasing factor, which contributes to increased formation of LH before ovulation. After ovulation, the corpus luteum secretes a lot of progesterone, but estrogen levels decrease. Progesterone stimulates the production of LTG, which in response enhances the activity of the corpus luteum and increases the release of progesterone. Progesterone suppresses the formation of LH, which leads to a deterioration in the blood supply to the uterine mucosa and the onset of menstruation. Left without hormonal support, the corpus luteum gradually fades away. A decrease in progesterone levels causes the pituitary gland to release FSH-releasing factor - and the cycle begins all over again. Thus, the dynamics of the secretion of ovarian hormones can be schematically depicted as follows. If the level of each hormone on the days of menstruation is taken as 100%, then they will be distributed throughout the cycle as follows: The most high levels estrogens are observed in the preovulatory phase (approximately 10-12 days from the start of menstruation in a normal 28-day cycle), lower in the luteal phase (from the 16th day of the cycle), minimal - at the beginning of the follicular phase (after menstruation). Differences in estrogen levels reach 10-fold values. The level of progesterone is highest in the middle of the P phase (days 16-20 of the cycle), 25 times less at the beginning of the cycle and increases before ovulation (days 13-15 of the cycle). The concentration of androgens fluctuates much less, and the highest value is observed before ovulation.

Thus, one system The pituitary gland-hypothalamus-ovaries together with the nervous system, acting on the principle of feedback, automatically ensures cyclic processes specific to the female body. The endometrium is most sensitive to the action of ovarian hormones due to the presence of a large number of estrogen and progesterone receptors in the cytoplasm and nuclei of its cells. The number of estradiol receptors in the endometrium reaches a maximum in the middle of the first phase of the menstrual cycle and then decreases; The maximum content of progesterone receptors occurs during the preovulatory period. During the menstrual cycle, the endometrium grows, the thickness of which at the end of the second phase of the cycle increases 10 times compared to the first phase of the cycle. According to ultrasound scanning, the thickness of the premenstrual endometrium reaches 1 cm. Along with the growth of the endometrium, cyclic changes in the glands, stroma and blood vessels occur in it. When histologically assessing the state of the endometrium, a proliferation phase (early, middle and late), corresponding to the follicular phase of the menstrual cycle, and a secretion phase (early, middle and late), corresponding to the luteal phase of the cycle, are distinguished.

At the end of the luteal phase of the menstrual cycle, menstruation occurs, during which the functional layer of the endometrium is shed. Menstruation is a consequence of a decrease in the level of ovarian hormones (estrogens and progesterone) in the blood; circulatory disorders in the endometrium (dilation and thrombosis of veins, arterial spasm, focal necrosis); increasing intravascular fibrinolysis, reducing blood coagulation processes in endometrial vessels; increasing the content of prostaglandins in the uterus and increasing the contractile activity of the myometrium. The cessation of bleeding is mainly due to the regeneration of the endometrium due to the epithelium of the remnants of the glands preserved in its battle layer; regeneration begins on the second day of the menstrual cycle even before the end of the discharge. Stopping bleeding is facilitated by increased platelet aggregation in endometrial vessels under the influence of prostaglandins.

Ovarian hormones cause cyclic changes in other parts of the reproductive system. In the first phase of the menstrual cycle, under the influence of estrogens, the contractile activity of the myometrium increases, and in the second phase it decreases. The isthmus of the uterus, expanded in the first phase of the menstrual cycle, narrows in its second phase. In the glands of the cervical canal, in the first phase of the cycle, the secretion of mucus increases - from 50 mg to 700 mg per day at the time of ovulation, while its structure changes - in the ovulatory period, the mucus is liquid, easily permeable to sperm, and is most viscous. In the second phase of the cycle, the secretion of the glands of the cervical canal decreases sharply, the mucus becomes viscous and opaque. During the menstrual cycle, the structure of the vaginal epithelium and, as a result, the cellular composition of the vaginal contents changes: as ovulation approaches, the number of superficial keratinizing cells in the vaginal contents increases, the peristaltic movements of the fallopian tubes and the vibrations of the cilia of the epithelium lining them increase.

In the mammary glands, in the first phase of the menstrual cycle, under the influence of estrogens, there is a proliferation of lactocytes - glandular cells lining the cavity of the alveoli; in the second phase of the cycle, secretory processes predominate in lactocytes, which is associated with the influence of progesterone. IN premenstrual period The mammary glands become slightly engorged due to fluid retention in the connective tissue. In some women, engorgement is significant and is accompanied by painful sensations (mastalgia).

In addition to changes in the organs of the reproductive system, cyclical changes are observed in functional state other systems of the female body. It has been established that the excitability of the cerebral cortex changes during the menstrual cycle. Thus, in the premenstrual period, inhibition processes intensify, the ability to concentrate decreases, performance decreases, and on the eve of menstruation, sexual activity decreases. In the first phase, the tone of the parasympathetic part of the autonomic nervous system increases, in the second phase - the sympathetic one. Changes in water-salt metabolism and function of cardio-vascular system lead to fluid retention in the body during the premenstrual period. All of these changes are caused mainly by ovarian hormones (estrogens and progesterone), the action of which is realized through cellular receptors of steroid hormones and the system of neurotransmitters (transmitters of humoral and nerve impulses).

Menstrualnyj_cikl_ovuljacija_gormonalnaja_reguljacija.txt · Last changes: 2012/06/25 23:58 (external change)