I came across a most interesting article on the Internet, in my opinion, on the influence of hormones on the course of pregnancy. I present it to your attention

Hormones are the main regulators that ensure the functioning of our body. Their merits are also great in maintaining pregnancy and giving birth to a child. We will talk about them further.

Hormones are biologically active substances that are produced by the endocrine glands: the thyroid gland, the pituitary gland (located at the base of the brain), the adrenal cortex and the ovaries. During pregnancy, the body of the unborn child and the placenta also participate in the production of biologically active substances necessary for the intrauterine development of the baby. Moreover, during this period, the concentration of hormones changes depending on the period of gestation of the baby. Therefore, when assessing the risk of complications and the well-being of the expectant mother and her child, doctors also focus on the level of biologically active substances in the woman’s body. Their shortage or excess is a signal of possible problems. So what substances are responsible for the onset and successful development of pregnancy?

Where does it all begin?

From the 4th day of the menstrual cycle in the right or left ovary, the so-called dominant follicle stands out among the follicles, in which the egg will mature. Under the influence of FSH - follicle-stimulating hormone, which is produced by the pituitary gland - this follicle grows and, as it matures, also begins to produce hormones - estrogens. Having reached a diameter of 15 mm, under the influence of luteinizing hormone (LH), the dominant follicle ruptures, and a mature egg emerges from it, which is fertilized by sperm. The place where the egg came out turns into the corpus luteum. It will produce progesterone under the influence of LH and prolactin. Estrogens and progesterone prepare the uterine lining to “receive” a fertilized egg.

hCG

As soon as the fertilized egg is implanted in the uterus and a fertilized egg is formed, human chorionic gonadotropin (hCG) begins to be produced, a hormone characteristic only of a developing pregnancy. HCG, in turn, stimulates the corpus luteum to continue producing progesterone. HCG can be detected in a woman’s body from the 14th day after fertilization, even if there is no delay in menstruation. Normally, during a normally developing pregnancy, the level of this hormone should increase every 2-3 days. Based on the dynamics of this indicator, one can judge the development of the fertilized egg up to 8-10 weeks. Then the hCG level decreases and remains constant throughout the pregnancy. A low concentration of hCG or the absence of its growth may indicate inferiority, as well as the death of the fertilized egg.

Early toxicosis

At the beginning of pregnancy, women may complain of nausea, indigestion, and impaired taste - signs of so-called early toxicosis. Doctors explain this phenomenon by hormonal changes in the body of the expectant mother. In reality, such symptoms are associated with an imbalance in thyroid hormone levels in pregnant women. The structure of hCG is very similar to TSH. For this reason, in the first trimester, when the level of hCG rises rapidly, the pituitary gland begins to produce less thyroid-stimulating hormone. Accordingly, the level of free T4 increases. This phenomenon is called transient thyrotoxicosis. It may be accompanied by nausea, vomiting and other symptoms characteristic of early toxicosis. After 12–14 weeks, the pituitary gland gets used to the changes, the TSH level gradually returns to normal, unpleasant symptoms disappear, and the expectant mother’s well-being improves.

The corpus luteum “lives” only 12–14 days. If pregnancy does not occur, it will resolve, and menstruation will occur in response to a decline in hormone levels. When fertilization occurs, the corpus luteum supports the pregnancy by producing progesterone until 12 weeks. Then the placenta will take over this function.

Progesterone

This is the main hormone of pregnancy. The corpus luteum, by producing progesterone, meets the needs of the developing pregnancy until approximately 10–12 weeks. By determining the level of progesterone during these periods, the doctor can assess the activity of the corpus luteum and, if necessary, prescribe replacement therapy with progesterone drugs. Stimulates the production of progesterone hCG. The more actively the fertilized egg produces human chorionic gonadotropin, the better the corpus luteum produces progesterone. From the 15th week, the placenta begins to synthesize progesterone and the concentration of this hormone increases sharply. At the end of pregnancy, progesterone levels are 8–10 times higher than in the first trimester. Before childbirth, when the contractile activity of the uterus is important, its content drops sharply.

The main task of progesterone is to prevent the endometrium from being rejected and prepare it for implantation of a fertilized egg. In addition, this hormone is a powerful relaxant. It relaxes the uterus and at the same time the bladder and blood vessels, which is why a pregnant woman may experience a frequent urge to urinate and lower blood pressure.

Estrogens

Outside of pregnancy, they are produced by the ovaries, in the first half of pregnancy by the corpus luteum, and in the second half by the placenta. The most active of them is estradiol. Lack of estrogen at the beginning of pregnancy leads to disturbances in the development of the placenta precursor - chorion - and termination of pregnancy. In the second half of pregnancy, the level of estrogen increases 12 times or more, since the adrenal glands of the unborn baby and the placenta are involved in the production of these hormones. Subsequently, throughout pregnancy, estrogen levels should gradually increase. Before birth, at 39–40 weeks, the concentration of estrogen increases by 50–100 times compared to the initial one. This is necessary to prepare the birth canal and “ripen” the cervix.

Prolactin

It is produced by the anterior lobe of the pituitary gland. During pregnancy, prolactin production is stimulated by high levels of estrogen. The main task of this hormone is to initiate and maintain lactation. Prolactin also affects the formation of embryonic lung tissue. At the beginning of pregnancy, the level of this hormone is low; it begins to increase in the second half of gestation, and in some women colostrum may be released from the nipples. Prolactin suppresses the activity of the ovaries, so when a mother breastfeeds her baby, she usually does not have menstruation. After six months, its effect weakens and menstruation may reappear.

Oxytocin

The posterior lobe of the pituitary gland is involved in its production. This is a powerful stimulator of uterine contractions. It is generally accepted that before childbirth its level rises sharply, which is not entirely true. In fact, before childbirth, it is not the level of the hormone that increases, but the number of receptors for it, that is, sensitivity to oxytocin increases. Therefore, the longer the pregnancy, the more clearly the woman feels uterine contractions.

It is believed that the signal for the onset of labor is given by the child, and it begins thanks to oxytocin and prostaglandins. By the way, the production of oxytocin is influenced by the “hormones of joy” - endorphins and the “hormone of fear” - adrenaline: the first increase the level of oxytocin, the second - decreases. Conclusion: do not be scared during childbirth and do not cower in fear when contractions begin, but enjoy the process of giving birth to your baby.

If labor is weak, oxytocin is used to stimulate it. After the birth of the baby, due to oxytocin, the uterus gradually returns to its normal size. By the way, it is lactation and the process of breastfeeding by a child that increases the production of its own, endogenous, oxytocin and promotes contraction of the uterus.

Thyroid hormones

These include 2 thyroid hormones: T3 (triiodothyronine) and T4 (thyroxine), synthesized by the thyroid gland, and TSH (thyroid-stimulating hormone), which is produced by the pituitary gland and regulates the functioning of the thyroid gland. Both thyroid hormones can be either free (free T3 and T4) or bound (total T3 and T4) to protein, but the biological activity of the hormones is manifested only in the free fraction.

For normal, including intellectual development of the unborn child, a strictly defined level of thyroid hormones is necessary. Low or increased concentrations increase the risk of miscarriage and can lead to disturbances in the development of the baby. That is why the levels of TSH and free T4 are determined in all expectant mothers in the early stages of pregnancy. These parameters are called the “mirror of thyroid health.” The levels of total T3 and T4 are normally always elevated during pregnancy, so it makes no sense to determine them.

In order for the level of these hormones to be sufficient, a woman’s body must receive iodine. So iodized products are a good prevention of problems with the intellect of the unborn child and with pregnancy.

When a young family is planning a child, it is advisable to undergo various examinations of both spouses. This includes checking your hormonal levels. The rapid onset of pregnancy and its normal course largely depend on hormones.

Such an examination is especially indicated for those women who experience hyperandrogenism, if there have been pregnancies with an unfavorable outcome, or if pregnancy does not occur a year after unprotected sexual intercourse.

What hormones affect conception?

Here is a list of hormones responsible for pregnancy:

• follicle-stimulating hormone;
• luteinizing hormone;
• prolactin;
• estradiol;
• progesterone;
• testosterone;
• DEA sulfate;
• dehydroepiandrosterone sulfate DHA-S (DHEA-S);
• thyroxine – free (FT4) and total (T4).

The influence of hormones on conception is undeniable. If the production of at least one of them is impaired, this can lead to problems with pregnancy. When planning pregnancy, hormones are checked in the morning on an empty stomach.

Follicle-stimulating hormone (FSH) is responsible for the growth of the follicle in the ovary, as well as the formation of estrogen. Estrogen promotes the growth of the endometrium in the uterus. Luteinizing hormone (LH) is responsible for the completion of egg formation in the ovary and ovulation, and it also stimulates the production of progesterone. And it is these hormones that are monitored first.

Another hormone is prolactin. It can suppress the formation of FSH, and ovulation directly depends on this. If this hormone is not normal, then ovulation will not occur and pregnancy simply cannot occur.

Testosterone is generally a male sex hormone, but it is also produced in small quantities in women. And if its production is impaired, this can lead to ovulation disorders and miscarriage during pregnancy. The level of this hormone also depends on external factors such as smoking, drinking alcohol, severe burns, strict diets and poor nutrition.

DEA sulfate is another male hormone that is produced in small quantities in a woman’s adrenal glands. At An increase in the concentration of this hormone causes disruption of the ovaries and, as a result, infertility.

An increased level of dehydroepiandrosterone sulfate DHA-S (DHEA-S) is indicated by excessive male-pattern hair growth. Disturbance in the production of this hormone can be caused by heavy physical activity, smoking, stress, etc.

And the last hormone is thyroxine. It regulates metabolism, processes of breakdown, synthesis of fats, proteins, carbohydrates, as well as growth, development and reproduction, body temperature and oxygen metabolism in the body.

Hormones are biological substances that are produced by the endocrine system. They control and influence processes in the body such as:

1. egg maturation;
2. pregnancy;
3. childbirth;
4. lactation, and much more.

Indications for testing for hormonal disorders may be:

• irregular monthly cycle;
• sudden weight gain or loss;
• lack or decrease in sexual desire;
• emotional instability;
• long absence of pregnancy (from six months);
• miscarriage;
• frozen pregnancy;
• the need for IVF.

The preparation of the body for conceiving and bearing a child is controlled by hormones such as:

1. follicle-stimulating (FSH);
2. anti-Mullerian;
3. luteinizing (LH);
4. prolactin;
5. progesterone;
6. testosterone;
7. estrogen;
8. estradiol;
9. thyroid hormones.

If a long-awaited pregnancy does not occur or is interrupted, this most often indicates a hormonal imbalance. In such cases, it is necessary to urgently donate blood for hormones in order to diagnose the problem and contact a specialist.

Follicle stimulating (FSH)

This hormone is produced by a small but very important gland in the brain - the pituitary gland. Entering the blood, FSH affects the growth and maturation of follicles. The level of this biological substance varies depending on the phase of the menstrual cycle. It is highly likely to determine such an important process for conception as ovulation. Most often, blood donation to check FSH levels is prescribed from days 3 to 6 of the cycle along with luteinizing hormone.

Luteinizing (LH)

A pituitary hormone that affects the reproductive system of both women and men. If abnormalities in LH occur, women do not ovulate, and men do not produce testosterone.

The ratio of FSH and LH, affecting conception and the ability to become pregnant

The pituitary hormones FLG and LH play a dominant role in the body of every woman who wants to become pregnant. during the process of conception. They ensure proper functioning of the ovaries and stimulate them to produce sufficient amounts of estrogen and progesterone.

At the beginning of the cycle, FSH predominates in women, but towards the middle there is a sharp increase in the concentration of LH, which ensures ovulation. In men, these hormones are responsible for spermatogenesis, but their levels almost never fluctuate.

A woman's menstrual cycle consists of three phases: follicular, ovulatory and luteal.

• In the follicular phase (from day 1 of the cycle), FSH predominates. Its norm is 1.9-11.0 mIU/ml.
• In the ovulatory phase (days 13-15 of the cycle), the FSH level rises to 4.8-20.5 mIU/ml.
• During the luteal phase, FSH concentration decreases and varies from 1 to 9 mIU/ml.

During ovulation, the egg leaves the follicle and the corpus luteum forms in its place. During this period, there is no need for a large amount of FSH, because the body is preparing for a possible pregnancy. If conception does not occur, then this hormone begins a new menstrual cycle, preparing the next follicle with an egg for fertilization.

If we talk about LH, then in the follicular phase its work is reduced only to stimulating ovarian cells that produce estrogens. The LH norm at this time is 1.4-8.6 mIU/ml. But in the ovulatory phase there is a sharp increase in LH concentration to 14.3-75.8 mIU/ml. In the luteal phase, LH again declines to 1–14 mIU/ml.

Any deviations from the norm may be evidence of serious health problems.

Progesterone

For pregnancy, this is one of the main hormones produced by the ovaries. Progesterone is responsible for the proper attachment of the fertilized egg to the inner wall of the uterus - the endometrium, and also eliminates excessive activity of the uterus after the fertilized egg has settled in it.

If tests show a lack of progesterone, even if pregnancy occurs, there is a risk of spontaneous miscarriage due to detachment of the ovum. The norm of progesterone in the early stages of pregnancy is from 12 ng/ml; in late stages it can reach 172 ng/ml.

The following factors may indicate a lack of progesterone:

1. increased uterine tone;
2. bleeding from the vagina;
3. nagging pain in the lower abdomen.

If at least one of these signals occurs, you should immediately consult a doctor. In such cases, gynecologists prescribe inpatient treatment or prescribe taking progesterone in tablets to increase its level in the blood.

In some cases, an increased level of progesterone in the blood indicates multiple pregnancy, and not about health problems.

We invite you to watch a video about how progesterone affects the conception of a child and the normal course of pregnancy:

Testosterone

This hormone influences the proper development of follicles. An increase in testosterone can either prevent ovulation or, if pregnancy has already occurred, lead to spontaneous miscarriage. Blood is tested for this hormone on days 5-7 of the cycle.

If testosterone levels are very elevated, this may indicate the presence of tumors in the ovaries and adrenal dysfunction. Reduced concentrations of this substance are most often associated with endometriosis and uterine fibroids.

Estrogen

This biological substance is also called the hormone of female attractiveness. Estrogen is responsible for a woman's ability to conceive and bear a child. One type of estrogen is estradiol.

Estradiol

Estradiol is produced by the ovaries. Its level affects the readiness of the uterus to grow with the fetus, reliably protecting it from external irritants. You can take an estradiol level test at any time of the day. The most accurate results are observed before the onset of ovulation. Fluctuations in the level of this hormone can lead to the death of the placenta and miscarriage, the development of Down syndrome in the fetus, and fetal hypoplasia.

Prolactin

The main function of prolactin is to prepare the mammary glands for breastfeeding and help other organs produce FSH, thyroid hormones and estrogens. Doctors most often prescribe a test to determine the level of this substance in the blood at the stage of pregnancy planning. A low level of prolactin can be a sign of infertility, and an increased level can signal hyperfunction of the thyroid gland, pituitary tumors, and polycystic ovary syndrome.

TSH

TSH is a thyroid-stimulating hormone produced by the pituitary gland. The functioning of the thyroid gland depends on it. TSH is responsible for maintaining proper metabolism in the pregnant woman and the fetus. A normal level of TSH in the blood prevents the development of hypoxia in the unborn child and anemia in the mother. TSH also stimulates the production of thyroid hormones such as T-triiodothyronine and T4-thyroxine.

In pregnant women, the level of these hormones may fluctuate depending on the timing. If fluctuations occur within the acceptable norm, then this does not indicate any pathology. But sudden surges in these hormones can lead to tachycardia, high blood pressure, and migraines.

Anti-Mullerian (AMG)

AMH is produced in both female and male bodies. In expectant mothers, the production of this substance is carried out by the ovaries. AMH regulates the body's reproductive abilities. This hormone reaches peak values ​​in a woman’s body by the age of 30 and decreases after 40.

Which ones interfere with getting pregnant?

Any hormonal disruptions in the body of the expectant mother can cause the inability to conceive and bear a child, because the successful maturation of the dominant follicle, the release of the egg, its ability to attach to the endometrium, the successful development of the fetus and childbirth on time depend on the correct balance of hormones in the body.

When a couple cannot conceive a child for a long time, the first thing the doctor focuses on is the ratio of FSH and LH in the woman’s body. A high level of FSH almost always indicates dysfunction of the reproductive system and the development of infertility.

Can a woman get pregnant with elevated FSH? With an increased level of FSH in the blood, the body receives a corresponding signal and begins to actively reduce the quality of eggs. This reduces the chances of fertilization, so Spontaneous pregnancy in women with elevated FSH concentrations is almost impossible. This problem can most often be solved only with the help of hormonal therapy.

Norms for women depending on the phase of the cycle

Norm for men

It is difficult to overestimate the importance of substances such as hormones in conscious family planning and pregnancy. They affect a person’s emotional state, his appearance, and his ability to reproduce. Not only women, but also men need to monitor their hormonal levels. Any imbalance can lead to irreparable consequences, which can be avoided if you get tested on time and seek help from specialists.

Hormones are produced by numerous endocrine glands. In the human body there are more than a hundred hormones known to science, but their quantity is measured in micrograms (10−6) and nanograms (10−9). The role of hormones is colossal: any minimal change in their level leads to a change in the functioning of millions of cells in the body.

It is thanks to hormones that we are able to reproduce, maintain pregnancy, and intrauterine development. During pregnancy, the level of some hormones important for the fetus changes slightly (thyroxine, cortisol), while the level of others increases several times (progesterone, prolactin). In addition, there are hormones that in a healthy person appear in the body only during pregnancy (chorionic gonadotropin, placental lactogen). A change in the ratio of hormones during pregnancy starts the process of labor and ensures its normal course, and then recovery during the postpartum period.

Hormones during pregnancy: it all starts with human chorionic gonadotropin

The moment that triggers hormonal changes in the body is the introduction of the fertilized egg into the wall of the uterus (implantation). During implantation, the cells of the fertilized egg form villi, which connect with the blood vessels of the uterus, together forming a special organ - the chorion. The chorion produces the first pregnancy hormone, which is called “human chorionic gonadotropin” (hCG). HCG in the body of a healthy person is formed only during pregnancy, because only in this case the chorion develops. This made it possible to use the determination of this hormone to diagnose the onset of conception. The simplest pharmacy pregnancy test is based specifically on the determination of hCG excreted in the urine. The level of hCG directly depends on the development of the chorion, and therefore on the duration of pregnancy: it doubles every two days, reaching its peak at 8–10 weeks. Moreover, its level differs from the original zero level by 100 thousand times! Afterwards, it begins to gradually decrease, remaining almost at the same level in the second half of pregnancy. By the rate of increase in hCG in the blood in the first trimester, one can judge whether the pregnancy and fetus are developing normally.

The appearance of this hormone in the blood is a signal to the body that pregnancy has occurred and a restructuring of the entire metabolism is required. HCG provides support for the vital activity of the corpus luteum in the ovary, blocking the onset of the next menstruation. In a non-pregnant woman, the corpus luteum fades within 2 weeks, and in the presence of hCG continues to exist for the first 3-4 months of pregnancy. With the blood flow, hCG enters the main regulatory center of the body - the pituitary gland. And the pituitary gland, having received such a signal, rearranges all hormonal activity of the body. The adrenal glands also react to the level of hCG in the blood, changing the synthesis of their hormones. In addition, the level of hCG is important for the development of the chorion itself and its transformation into the placenta. The presence of hCG in the body itself is not felt by a woman in any way, but it is this hormone that stimulates the production of female sex hormones (estrogens and progesterone), which cause changes in well-being.

Hormones during pregnancy: estrogens prepare the mother for lactation

Estrogens are a group of hormones, the main of which are estrone, estradiol and estriol, produced primarily in the ovaries. In the first 4 months of pregnancy, the main source of estrogen is the corpus luteum (a temporary organ that is formed in the ovary after ovulation at the site of the released follicle each menstrual cycle), and then the formed placenta. During pregnancy, the level of estrogen in a woman's blood increases 30 times. Estrogens during pregnancy affect many important aspects of fetal development, for example, the rate of cell division in the early stages of embryo formation. Under their influence, the mammary glands enlarge, milk ducts develop and grow in them, preparing for lactation. A woman's breasts swell and become more sensitive. Estrogens have an impact during pregnancy and on general well-being: they can become the “culprit” for headaches, dizziness and insomnia. It is believed that estrogens give the expectant mother a special femininity during pregnancy, as if she is blossoming. However, they can also cause excessive skin pigmentation or hair loss.

Estrogens help increase the size of the uterus, and also participate in preparing the body for childbirth: they increase the sensitivity of the uterine muscle to oxytocin (the pituitary hormone that causes contractions), soften the connective tissue of the cervix, promoting its opening.

Determining the level of estriol in the blood of pregnant women makes it possible to identify disturbances in the development of pregnancy. Thus, a decrease in this hormone is observed with some fetal malformations, intrauterine infection and placental insufficiency.

Hormones during pregnancy: progesterone protects the fetus

Progesterone is the hormone that maintains pregnancy. Its main source in the early stages of pregnancy is the corpus luteum, and when it disappears after 12 weeks, the placenta takes over its function. During pregnancy, progesterone levels gradually increase; its maximum level can be 20 times higher than the initial level.

In the second phase of the menstrual cycle, progesterone ensures the development of the endometrium so that it is able to receive a fertilized egg when pregnancy occurs. During implantation of the fertilized egg, it contributes to its reliable anchorage in the endometrium and adequate nutrition of the fetus. Progesterone during pregnancy prevents the onset of the next ovulation, blocks the mother’s body’s immune response to the fetus as a foreign object, and activates the areas of the mammary glands responsible for milk production. Under the influence of progesterone, the mucus in the cervix becomes thick, forming a so-called mucus plug that protects the contents of the uterus from the outside world.

As the period increases, progesterone during pregnancy helps to stretch and relax the uterine muscle, preventing premature termination of pregnancy. But here it is not selective: it relaxes any smooth muscles. And if in the case of the uterus this is good, then its effect on other muscular organs leads to various ailments. Thus, it relaxes the muscle sphincter between the stomach and esophagus, which is why pregnant women often suffer from nausea and heartburn. Makes the intestines less active, causing constipation and bloating. Reduces the tone of the ureters and bladder, which promotes frequent urination and increases the risk of kidney inflammation. Reduces vascular tone, leading to fluid retention in the body, swelling, drop in pressure and varicose veins. In addition, progesterone affects the nervous system of the expectant mother; it is responsible for drowsiness, irritability and mood swings.

During a normal pregnancy, there is no need to control progesterone. But in women at risk of miscarriage, periodic testing allows the gynecologist to observe changes in progesterone levels for the purpose of prognosis and correction of treatment. Medicines containing progesterone occupy a leading place in the treatment of threatened miscarriage.

Hormones during pregnancy: placental lactogen stores useful substances for the baby

The production of placental lactogen (PL) increases with the duration of pregnancy, in accordance with the weight of the placenta and fetus. At the 36th week of pregnancy, the placenta secretes about 1 g of lactogen per day. Placental lactogen rearranges the mother’s metabolism to ensure the growth and development of the fetus. Thus, it interferes with the synthesis of proteins in a woman’s body, which increases the supply of amino acids that the fetus uses for its formation. It also maintains the level of glucose in the mother's blood for consumption by the fetus. Thanks to placental lactogen, a pregnant woman gains weight. Its influence explains the increased appetite of the expectant mother and her special preferences for certain foods. In addition to its metabolic function, PL enhances the production of progesterone, stimulates the development of the mammary glands and suppresses the female body’s immune response to fetal proteins, which is important for the normal development of pregnancy. Since the placenta is the only source of this hormone, its determination is a direct indicator of the condition of this temporary organ of pregnancy. It also helps to find out the condition of the baby - with hypoxia (oxygen starvation) of the fetus, the concentration of placental lactogen in the blood decreases almost 3 times.

Other hormones during pregnancy

Relaxin intensively secreted in the ovaries and placenta in the late stages of pregnancy. Relaxin relaxes the cervix during childbirth and weakens the connection of the pubic symphysis with other pelvic bones. Thus, this hormone prepares the mother’s body for childbirth. In addition to this direct effect, relaxin promotes the growth and formation of new blood vessels, which reduces the risk of cardiovascular disease and increases the life expectancy of women who have undergone pregnancy and childbirth.

Prolactin– a hormone of the pituitary gland (a gland located in the brain), responsible for lactation. During pregnancy, its level increases 10 times. During pregnancy, prolactin stimulates the growth and development of the mammary glands, gradually preparing them for the production of colostrum and milk. Under its influence, the structure and size of the breast changes - adipose tissue is replaced with secretory tissue. In addition, it regulates the volume and composition of amniotic fluid, participates in water-salt metabolism, and increases the threshold of pain sensitivity before childbirth. An increased concentration of prolactin during pregnancy is also necessary for the child, since the hormone promotes the development of the lungs and is involved in the formation of surfactant (a special substance that covers the inner surface of the lungs and ensures their expansion during the first breath of the newborn).

Oxytocin during pregnancy, it is formed in the hypothalamus of the brain and transported to the posterior lobe of the pituitary gland, where it accumulates. The main property of oxytocin during pregnancy is the ability to cause strong contractions of the uterine muscle (contractions). Oxytocin also promotes the release of milk from the mammary glands. There is an opinion that this hormone has an effect on the psyche of the expectant mother, causing a feeling of attachment and tenderness for the child, as well as a feeling of satisfaction, calmness and security, and reduces the level of anxiety.

The maximum amount of oxytocin is produced at the end of pregnancy, which is one of the triggers of labor, and this hormone is released into the blood mainly at night, so most often labor begins at night.

Thyroxine– thyroid hormone. The level of this hormone during pregnancy does not change so much during pregnancy compared to female sex hormones (at the beginning of pregnancy, the production of thyroxine increases by a third), but one cannot fail to note its important role in the development of the fetus. The formation and formation of all fetal organs, including the nervous system, is ensured by thyroxine and other thyroid hormones from the mother. Reduced production of thyroxine can lead to disruptions in the formation of the brain and central nervous system of the fetus, and an increase in its level increases the risk of miscarriage. Sometimes increased synthesis of thyroxine at the beginning of pregnancy can affect well-being: the pulse quickens, sweating, insomnia, tearfulness, and irritability appear.

Insulin, produced by the pancreas, is the main regulator of carbohydrate metabolism and blood glucose levels. At the beginning of pregnancy, insulin levels increase slightly, which lowers blood glucose levels, causing morning weakness and dizziness. After the 14th week, placental lactogen increases the sensitivity of body tissues to insulin, enhances its breakdown, and blood glucose levels increase. At the same time, the circulation of free fatty acids in the blood increases. And if the bulk of glucose goes to energy supply for the fetus, then free fatty acids go to energy supply for the mother. An increase in blood glucose levels is fraught with the development of diabetes mellitus in pregnant women, so it is necessary to regularly monitor blood sugar.

Pregnancy causes a slight increase in the level of major adrenal hormones - mineralocorticoids and glucocorticoids. The task of mineralocorticoids, in particular aldosterone, is to regulate water-salt metabolism; their concentration doubles towards the end of pregnancy, which leads to water and sodium retention in the body, contributing to edema and increased blood pressure.

Glucocorticoids, in particular cortisol and hydrocortisone, help mobilize amino acids from maternal tissues during the synthesis of fetal tissues and suppress the immune system so that the expectant mother’s body does not reject the fetus. The side effects caused by these hormones are thinning hair, hyperpigmentation of the skin, formation of stretch marks, and increased growth of body hair.

Time when everything changes again

A couple of weeks before giving birth, hormonal changes during pregnancy enter a new phase: the body rapidly transforms from “preserving pregnancy” to “giving birth.” From the 36th week of pregnancy, there is an increase in estrogen secretion and a decrease in progesterone levels. An increase in estrogen levels leads to an increase in the content of prostaglandins in the uterus, which, when released into the blood, stimulate the secretion of oxytocin in the pituitary gland in the woman and fetus, cause the destruction of progesterone, and also directly trigger labor by causing contraction of the uterine muscle.

All hormonal changes during pregnancy are aimed at the normal course of pregnancy and a successful birth. If for some reason the body cannot cope with hormonal function, then doctors recommend replacing its own hormones - hormonal medications designed to correct the existing disorder. Prescribing such drugs requires a balanced approach, but no alternative has yet been found.

What hormones does the placenta produce?

The placenta is a temporary organ of pregnancy that develops in the uterine cavity and performs a number of important functions aimed at providing sufficient conditions for the physiological course of pregnancy and normal development of the fetus. As an endocrine gland, the placenta is finally formed by the 14th–16th week of pregnancy. Starting from this period, it is the main source of estrogen and progesterone in the body of a pregnant woman. However, its hormonal function is not limited to these hormones. The placenta is a whole factory for the production of various hormone-like substances, of which not all have yet been discovered by scientists. It synthesizes almost all known hormones of the human body, as well as unique substances specific to pregnancy. These include hCG, already known to us, as well as placental lactogen.

Hormones are biologically active compounds. They affect human health and psyche. Many hormones are activated during pregnancy and support the mother’s body, help the fetus develop and create a strong bond between them. All processes and reactions adapt to the new situation. Some hormones come into play, others fade into the background.

Hormones are involved in metabolism, they ensure vital processes and growth of the body. These substances are produced by glands that make up the human endocrine system. Endocrine glands are located in different parts of the body and influence different processes.

Main glands:

• The pituitary gland is located in the brain, it exercises control over other glands, pituitary hormones determine the size of a person and the intensity of growth processes;
• the thyroid gland is located in the cervical region, its hormones are involved in metabolism;
• The parathyroid glands are located near the thyroid gland, they help regulate the synthesis of calcium and phosphorus;
• The thymus or thymus gland is located in the upper part of the chest, produces thymosin, which helps in creating the immune system;
• the pancreas secretes juice to digest food, as well as insulin, which regulates carbohydrate metabolism;
• the adrenal glands produce substances that participate in metabolism and support the functionality of the nervous system; the gland also produces sex hormones;
• the pineal gland or pineal gland is located in the brain, produces melatonin, which regulates the daily routine;
• the gonads are responsible for reproduction, their hormones develop secondary sexual characteristics (in girls, the shape of the skeleton and pelvis changes, the mammary glands enlarge, the figure is outlined, pubic and armpit hair appears, menstruation occurs, reproductive function is established).

Why you need to check your hormonal levels

Hormones are involved in all basic processes of the body: growth, development, metabolism, reproduction. For the body to function properly, the ratio of hormones must correspond to the gender and age of the person. There are standards for each hormone and each individual category of people.

Each indicator is important for a pregnant woman. Any changes in the analyzes reflect the process of fetal development. That is why hormones are monitored regularly by a doctor. Various methods are used to study hormonal levels.

Perinatal screening is mandatory - a group of studies that help determine the risk of developing defects in the fetus. Doctors recommend being screened at least twice. In the first trimester, studies are carried out at 11-12 weeks. In the second trimester, 16-19 weeks are appropriate.

In women, hormonal levels change after puberty, at the time of conception, and during menopause. A routine laboratory blood test can identify many diseases and even determine the location and nature of abnormalities. A blood test for hormones is an important part of the examination of a pregnant woman. Based on their results, the gynecologist can assess the condition of the mother and child and draw up the correct treatment plan.

What tests are done for hormones during pregnancy?

Because the chemical composition of hormones varies, there are different ways to study blood. During pregnancy, tests for pituitary hormones may be necessary:

• prolactin;
• thyroid-stimulating hormone.

Tests for sex hormones:

• estriol;
• testosterone.

Test for adrenal hormones:

• cortisol;
• adrenocorticotropic hormone;
• DHEA sulfate.

Thyroid hormone test:

• thyroid stimulating (TSH);
• triiodothyronine (T3);
• triiodothyronine (free T3);
• thyroxine (T4);
• free thyroxine (free T4).

Antibody test:

• thyroglobulin;
• thyroid peroxidase.

These hormones are studied as part of perinatal screening in the first and second trimesters. In the first trimester, PAPP-A and beta-hCG levels are measured. In the second, AFP, E3 and hCG hormones are examined. Control of 17-ketosteroids and 17-hydroxyprogesterone, as well as globulin, which binds sex hormones, is also necessary. At the same time, tests are carried out for hormones of the reproductive system (testosterone, estradiol) and the adrenal gland substance cortisol.

Human chorionic gonadotropin (hCG)

Closer to the 10th week of pregnancy, the placenta begins to intensively produce hormones. produced by the fetal membrane (chorion). Secretion begins immediately after the embryo attaches to the inner layer of the uterus. HCG is one of the most important hormones for humans, especially for maintaining pregnancy. This hormone controls the production of other substances necessary for pregnancy - progesterone and estrogen.

During a healthy pregnancy, hCG levels constantly rise. By 10-11 weeks, the concentration of the hormone in the blood decreases and does not change until childbirth. If there is a lack of hCG, a miscarriage occurs: progesterone does not sufficiently prepare the endometrium, the egg does not hold and leaves the uterus, and menstruation occurs.

It is the hCG hormone that confirms pregnancy. A simple test detects the hormone in the urine by 5-6 days after conception, but a blood test is more reliable. The hCG level makes it possible to calculate the period when a woman cannot accurately determine the day of conception.

HCG levels reflect the condition of the fetus, so the analysis allows you to find out about complications. For each stage of pregnancy, the norm of hCG in the blood is established, which confirms the correct development of the fetus.

An abnormal increase in hCG may indicate multiple pregnancies, diabetes mellitus, or preeclampsia (microdamage to the placenta). Sometimes an increase in hormone levels indicates developmental defects and hereditary diseases, such as Down syndrome.

A decrease in hCG occurs with an ectopic pregnancy, as well as a frozen one. This may be a manifestation of developmental delay, placental insufficiency (violation of the functionality of the placenta), spontaneous termination of pregnancy.

If your hCG level is high or low, there is no need to be alarmed. Perhaps the date of conception was entered incorrectly.

Placental hormones

Progesterone

During a certain period of the menstrual cycle, progesterone levels increase. The hormone is produced by the corpus luteum, which matures at the site of the follicle after it releases the egg on the day of ovulation.

This hormone is responsible for the readiness of the uterus for implantation and is considered essential during pregnancy. Progesterone promotes better attachment of the fertilized egg to the endometrium of the uterus. The hormone prevents miscarriage by reducing the tone of the uterus.

Without normal levels of progesterone, conception does not occur. The hormone sends signals to the central nervous system to prepare for conception. It preserves pregnancy and creates the necessary conditions for bearing and feeding a child. Progesterone also worries about a woman’s psychological state. It calms the pregnant woman, creates affection and love for the fetus.

On the other hand, progesterone affects the psyche, making a woman irritable and depressed. The hormone also retains salts and liquid, causes headaches, drowsiness, nausea, and increases urination. Thanks to progesterone, the mammary glands swell and hurt.

The concentration of progesterone doubles by week 8, and increases gradually by week 38. In the first trimester, the norm is 9 nmol/l and increases to 770 nmol/l by the third trimester.

Lack of progesterone is associated with pregnancy complications. It is possible to replenish hormone reserves with medication. Otherwise, the pregnancy ends in miscarriage or underdevelopment.

Placental lactogen

The level of placental lactogen determines the risk of chromosomal abnormalities. The hormone is secreted by the placenta. It is present in a woman’s blood from 5-6 weeks. Normally, the maximum placental lactone in the blood is observed at 37-38 weeks. After this period, the hormone level drops.

Studying the level of placental lactogen is aimed at assessing the condition of the placenta. The analysis allows for timely diagnosis of deficiency. A sharp decrease in the hormone by two times or more (compared to normal levels on a certain day of pregnancy) may indicate a delay in the development of the child. A decrease in the level of placental lactogen by 80% can lead to fetal death. The doctor must notice the decline in time to urgently prevent the reduction of the hormone.

The norm of placental lactogen is 0.05 mg/l in the early stages, increasing to 11.7 by 40 weeks. A lactogen test is performed if there are two history of miscarriages.

Estrogens

Estrogen levels are important during pregnancy. The hormone supports labor activity and helps the uterus grow. Estrogen also normalizes blood pressure, removes fluid, and relaxes blood vessels. Estrogens are produced by the baby's placenta and adrenal glands.

Free estriol improves blood circulation in the vessels of the uterus. The hormone affects the mammary glands and helps the body adapt to feeding the baby. Analysis for free estriol reveals fetoplacental insufficiency (impaired blood supply to the placenta), developmental delay, post-term pregnancy. At 5-6 weeks of pregnancy, the estriol norm is 0.6-2.5 nmol/l. By week 40, the hormone level rises to 111 nmol/l.

Ovarian hormones

In normal times (estrogen) is produced by the ovaries, and after conception also by the placenta. It supports the normal course of pregnancy, so its level is constantly increasing. First, an estradiol test can tell you about the condition of the placenta. A decrease in estradiol in the early stages may indicate a risk of pregnancy termination.

In the first week the norm is 800-1400 pmol/l, and in the last week 57100-99100 pmol/l. Immediately before birth, estradiol levels increase to the maximum. It is he who needs to be thanked for relieving pain during childbirth, since estradiol is a natural pain reliever.

At the psychological level, estradiol is responsible for readiness for the birth of a baby. The hormone affects the woman, and she begins to buy things, arrange the room and prepare for the birth of the child.

If you have a history of miscarriages, you need to monitor progesterone and estradiol both before and after conception. It is necessary to monitor the state of hormonal levels during preparation for fertilization, as it affects implantation and development of the fetus.

Adrenal hormones

Pituitary adrenocorticotropic hormone (ACTH) stimulates the production of mineralocorticoids and glucocorticoids by the adrenal glands. Under stress, ACTH levels increase and the secretion of adrenal hormones increases. Pregnancy is such a stress.

Effect of adrenal hormones:

• suppression of immunity, prevention of fetal rejection;
• regulation of water-salt balance through salt and fluid retention;
• weakening of hair;
• formations of stretch marks (stretch marks);
• skin hyperpigmentation;
• strong hair growth.

Thyroid hormones

During pregnancy, it is necessary to monitor the functionality of the thyroid gland. Insufficiency and excessive production of hormones by this organ can cause malformations in the fetus. The condition of the thyroid gland can be assessed using thyroxine and triiodothyronine.

An analysis of hormones during pregnancy of this gland is prescribed to those patients who have a history of problems with the organ. Indications may include severe fatigue, drowsiness, problems with hair, skin and nails, low blood pressure, swelling and sudden weight gain. All these signs may indicate thyroid dysfunction.

During pregnancy, a deficiency is often diagnosed, although an excess of thyroid hormones is also possible (hyperthyroidism). An excess is dangerous due to premature birth. Advanced hypothyroidism (lack of hormones) leads to fetal death in the womb and mental retardation.

The following hormones need to be examined:

• thyroid-stimulating (TSH), which stimulates the secretion of thyroid hormones (the norm is 0.4-4.0 mU/l, in pregnant women the norm is 0.4-2.0 mU/l);
• free thyroxine (free T4), which accelerates metabolism (normal 9-22 pmol/l, during pregnancy 8-21 pmol/l);
• triiodothyronine (free T3), which also accelerates metabolism, but is more active (the norm is 2.6-5.7 pmol/l, during pregnancy the values ​​​​remain normal).

Sometimes the endocrinologist also prescribes testing for antibodies to thyroglobulin (AT-TG) and thyroid peroxidase (AT-TPO) - proteins that appear in the blood when the gland is inflamed.

Pituitary hormones

Hormones from the pituitary gland, an endocrine gland located in the brain, also participate in the process of fetal growth. During childbirth, the uterus contracts under the influence. Postpartum lactation is carried out thanks to prolactin. Lack of prolactin reduces the amount of breast milk.

Oxytocin and prolactin are the so-called motherhood hormones. They help a woman feel love for her child, feel like a mother and enjoy feeding. These hormones tell a woman how to behave and how to set priorities. Nature, through hormones, forces a woman, like any female on the planet, to love and protect her child. In this way, the continuation of the species and the preservation of each population are carried out.

A woman’s desire to be close to her child and protect him depends on the concentration of maternal hormones. The concentration of maternity hormones changes gradually so that the woman’s psyche can prepare for the birth of the baby.

The hormonal system reacts sharply to external stimuli and internal changes. Therefore, a blood test for hormones during pregnancy is taken in the morning on an empty stomach. A few days before the procedure, you need to refrain from physical and emotional stress, eliminate alcohol and cigarettes.

It must be remembered that hormonal levels primarily depend on a woman’s mood. Its importance for the development of a healthy pregnancy is great, but almost any hormone can be replenished with medication. Therefore, do not panic if the analysis shows an excess or lack of the active substance.

The intensity of positive as well as negative effects from the growth of hormones during pregnancy depends on many factors: heredity, health, mood, individual characteristics.