Critical periods of embryogenesis. Time to be careful (critical periods of pregnancy) Major critical periods in fetal development

The scheme of examination of a pregnant woman to assess the state of intrauterine development of the fetus (Appendix No. 5 to the order of the Ministry of Health of Russia dated December 28, 2000 No. 457) The first stage of the examination (10–14 weeks of pregnancy) The second stage of the examination (20–24 weeks of pregnancy) The third stage

Development of the embryo and fetus The first month of intrauterine development is the period of the most intensive growth in the life of the organism: compared with the zygote, the embryo increases by 10,000 times. 1st week. The egg formed after fertilization moves from fallopian tube To

Periods of fetal development During pregnancy, lasting an average of 280 days, two periods of fetal development are distinguished - embryonic (embryonic), lasting from the moment of fertilization of the egg to 8 weeks of gestation, and fetal (fetal), lasting from 8

Developmental anomalies and diseases of the fetus, membranes and

Malformations and some diseases of the fetus Initially, the formation and development of a new organism is due to a combination of the genetic material of the parents, this material is affected throughout life by many environmental factors, lifestyle, etc. All these

Critical periods of life There is a certain psychological element of calm in the diet itself. nervous system, "healing" of spiritual wounds. In German literature, there is a term: "eat the fat of sadness." Lack of security, love, recognition, as a kind of hunger,

For antenatal protection of the fetus, it is important to know the critical periods of its development, when a high percentage of embryonic death and damage to individual organs and systems are observed. Under the action of damaging factors on the body of a pregnant woman, those organs and systems are the first to be affected, which at the time of exposure are in a state of increased differentiation and increased metabolism. In this regard, the rudiments of the nervous and cardiovascular systems are especially sensitive.

There are three stages of intrauterine development - the period of progenesis (the first 3 weeks), the period of embryogenesis (from the 3rd week to the 12th week), the period of fetal development (from the 4th month to birth.

The first critical period of development is the pre-implantation stage and implantation. The pre-implantation stage begins from the moment of fertilization and continues until the introduction of the blastocyst into the decidua of the uterus. Implantation in humans occurs on average on the 7-8th day after fertilization.

The action of damaging factors during this period (radiation, overheating, hypoxia, etc.) causes the highest death of embryos.

The second critical period - the period of organogenesis and placentation - begins with the moment of vascularization of the villi, which occurs at the 3rd week and ends by the 12th-13th week of intrauterine development.

The action of damaging factors during this period causes disturbances in the formation of the brain, cardiovascular system and other organs.

In addition to critical periods in the early stages of pregnancy, V. I. Bodyazhina draws attention to the average terms of intrauterine development of the fetus, which can also be considered as a kind of critical period of development. In fetuses at the 18-22nd week of ontogenesis, qualitative changes are observed in the bioelectrical activity of the brain, reflex reactions, hematopoiesis, hormone production, which in their nature approach the structures and processes characteristic of the body of a newborn.

In the second half of pregnancy, there is a decrease in the sensitivity of the fetus to the effects of damaging factors. This is due to the maturation and formation of the most important organs and systems - the nervous, cardiovascular, hematopoietic, etc., in connection with which the fetus acquires the ability to respond differently to the action of the environment.

It has been established that in the process of embryogenesis there is a multi-temporal maturation of the functional systems of the fetus, depending on their significance for the development of the organism at different stages of the intrauterine period. First of all, the systems and organs that are necessary to ensure the viability of the fetus are laid down and differentiated. This uneven prenatal development of the fetus is the basis of the theory of systemogenesis developed by P. K. Anokhin. According to this theory, the various components of any vital functional system, depending on the complexity of their organization, are laid down at different speeds, but by the time of birth they all become mature and begin to function as a single whole. One of the main patterns of the life of an organism is the continuous development and change of functional systems that provide it with adequate adaptation at various stages of postnatal life.

Nerve centers are grouped and begin to mature before the substrates innervated by them are formed and mature.

There are the following periods of fetal development during pregnancy:
pre-implantation(from the moment of fertilization of the egg with sperm until the introduction of the fertilized egg into the mucosa of the uterine wall);
implantation(attachment of a fertilized egg to the wall of the uterus);
organogenesis and placentation(the period of formation of all organs and tissues of the fetus, as well as the placenta);
fetal- the period of growth and development of formed organs and tissues.

Pre-implantation period

Normally, 12-14 days before the expected menstruation, ovulation occurs, that is, it has reached large sizes The egg leaves the ovary and enters the fallopian tube, where fertilization most often occurs. From this point on, pregnancy begins. A fertilized egg continues its journey through the fallopian tube for 4 days towards the uterine cavity, which is facilitated by:
contraction of the smooth muscles of the wall of the fallopian tube. These contractions normally occur in a unilateral direction - towards the uterine cavity from the end of the tube facing the abdominal cavity;
movement of the cilia of the mucous membrane, which covers the fallopian tube from the inside. The fluid in the tube begins to move, and with the flow of this fluid, the fertilized egg enters the uterus;
relaxation of the sphincter (circular muscle) in the junction of the fallopian tube with the uterus. This sphincter is designed to prevent a fertilized egg from entering the uterine cavity prematurely, before the uterus is ready to receive a fertilized egg.

The movement of the egg through the fallopian tube occurs under the influence of the female sex hormones estrogen and progesterone. Progesterone is a pregnancy hormone that early dates pregnancy is produced in the ovary (in place of the bursting follicle, a corpus luteum is formed, which produces in in large numbers This hormone contributes to the onset and maintenance of pregnancy). If progesterone is not produced enough, the egg from the fallopian tube will enter the uterine cavity late. With increased peristalsis of the fallopian tube, the fertilized egg will enter the uterine cavity before it can penetrate the mucous membrane, as a result of which the egg may die. Since in this case the pregnancy will not take place, there will be no delay in the next menstruation, the pregnancy will remain undiagnosed, unrecognized.

The period of advancement of a fertilized egg through the fallopian tube is considered the first critical period of pregnancy (from 12-14 to 10-8 days before the next menstruation). As a result of a violation of the complex mechanisms of regulation of the fallopian tube, the egg after fertilization can also be introduced into the wall of the tube (ectopic pregnancy).

Implantation period

This period also passes even before the expected menstruation, most often when the woman is still unaware of her pregnancy. Once in the uterine cavity, the embryo already consists of 16-32 cells, but it does not immediately penetrate into the uterine mucosa, and is in a free state for another two days. These two days from the moment the fertilized egg enters the uterine cavity to its attachment to the uterine wall constitute the implantation period. The place of implementation depends on a number of circumstances, but most often it is the anterior or posterior wall of the uterus.

The nutrition of the fetal egg during this period occurs due to the local dissolution of the mucous membrane of the uterine wall with the help of enzymes secreted by the fetal egg. After 2 days fertilized egg is introduced into the uterine mucosa, which contains a large amount of enzymes, glycogen, fats, trace elements, protective antibodies and other biologically active substances necessary for the further growth of the embryo.

The second critical period of pregnancy is implantation, that is, the attachment of the fetal egg to the wall of the uterus. If implantation fails, then the pregnancy ends under the guise of menstruation (in fact, this is an undiagnosed miscarriage at a very short time). Since there is no delay in menstruation, the woman does not even assume that she is pregnant.

The process of implantation is greatly influenced by hormonal factors: the concentration of hormones such as progesterone, estrogens, prolactin (a pituitary hormone - a gland located in the brain), glucocorticoids (adrenal hormones), etc.

Of great importance is the preparedness of the uterine mucosa for implantation, its readiness to accept a fetal egg. After abortions, curettage, prolonged wearing of an intrauterine device, infections, inflammatory processes the receptor (perceiving) apparatus of the endometrium may be disrupted, that is, the hormone-sensitive cells located in the uterine mucosa do not respond correctly to hormones, due to which the uterine mucosa is not sufficiently prepared for the upcoming pregnancy. If the fetal egg is not active enough, does not release the required amount of enzymes that destroy the uterine mucosa in a timely manner, then it can penetrate the uterine wall in the lower segment or in the cervix, resulting in cervical pregnancy or abnormal placentation (the placenta blocks the exit from the uterus partially or completely ).

The presence of adhesions (synechia) in the uterine cavity after inflammatory processes, curettage, as well as uterine fibroids, can also interfere with normal implantation.

Period of organogenesis and placentation

This period lasts from the moment the fetal egg is introduced into the uterine mucosa until 10-12 weeks of pregnancy, when all organs and tissues of the fetus, as well as the placenta, are fully formed ( children's place- a link between the fetus and the mother's body, through which the processes of nutrition, metabolism and respiration of the fetus occur in the womb). This is a very important period of intrauterine life, because. at this time, all the organs and tissues of the fetus are laid. Already on the 7th day after the fertilization of the egg, the mother's body receives a signal of pregnancy due to the hormone - chorionic gonadotropin (CG), which is secreted by the fetal egg. CG, in turn, supports the development of the corpus luteum in the ovary. The corpus luteum secretes progesterone and estrogens in sufficient quantities to maintain pregnancy. At the initial stage of pregnancy, before the formation of the placenta, the corpus luteum takes on the function of hormonal support for pregnancy, and if for one reason or another the corpus luteum does not work properly, then there may be a threat of miscarriage, miscarriage or non-developing pregnancy.

The entire period of organogenesis and placentation is also a critical period of intrauterine life of the fetus, because. the fetus is highly sensitive to the damaging effects of the environment, especially in the first 3-6 weeks of organogenesis. This critical period in the development of pregnancy is especially important, because. under the influence of adverse environmental factors, the embryo may die or develop abnormalities.

During these periods, the influence of environmental factors on the embryo is especially dangerous, including:
physical (ionizing radiation, mechanical effects); this can be the action of ionizing radiation, for example, in the conditions of a man-made disaster at nuclear facilities, mechanical effects in the form of vibration, and so on. in the relevant industries or at the time of sports training;
chemical: phenols, nitric oxide, pesticides, heavy metals, etc. - these substances can also enter the body of a pregnant woman if she works in the relevant industries or during repairs in a room where a woman stays for a long time. Chemicals include nicotine, alcohol, certain drugs such as those used to treat cancer, etc.;
biological (for example, herpes virus, cytomegalovirus, rubella virus, etc.).

It must be emphasized that during critical periods, harmful effects lead to the most severe consequences - the death of the embryo or the formation of gross malformations.

According to French researchers, if a pregnant woman for the first time in her life encountered cytomegalovirus, a pathogen that causes a disease that in adults can occur as a banal acute respiratory disease (acute respiratory disease) during pregnancy (as seen from a blood test for CMV immunoglobulins), especially on early terms, then in 1/3 of cases fetal malformations may occur. If, before pregnancy, she was already infected, the body turns on defense mechanisms to fight the virus in time, this probability decreases to 1%. The same can be said about the herpes simplex virus.

Of particular danger is the rubella virus when infected with it in the early stages of pregnancy. In such cases, a woman is recommended artificial termination of pregnancy, tk. there is a high risk of having a child with such malformations as microphthalmia - a malformation of the eyes, microcephaly - a serious malformation of the brain; deafness, congenital heart defects, etc.

Of the chemical compounds, lead, mercury, benzene, nicotine, carbon oxides and other substances that can cause malformations have a particularly adverse effect on the state of the embryo.

Some drugs are especially contraindicated during pregnancy (eg anticancer antibiotics); if they were taken, early termination of pregnancy is recommended. When taking some medicines a consultation with a geneticist is necessary, careful monitoring during pregnancy of the state of the embryo and fetus (ultrasound, blood test for chorionic gonadotropin, alpha-fetoprotein, estriol, which make it possible to suspect the presence of fetal malformations - the analysis is carried out at 16-20 weeks of pregnancy).

Women working in the chemical industry during pregnancy must be transferred to other, less dangerous workshops. As for the effect of radiation, if it affects a woman before the implantation of the embryo (during the pre-implantation period), in 2/3 of the cases the embryo dies. During the period of organogenesis and placentation, malformations often occur or intrauterine death of the embryo or fetus occurs.

At 7-8 weeks of pregnancy, the reverse development of the corpus luteum in the ovary usually begins: figuratively speaking, the ovaries transfer the function of hormonal support of pregnancy to the chorion (future placenta), and if the chorion is not sufficiently developed, not active, then there is a threat of termination of pregnancy.

7-8 weeks is also a critical period for the development of pregnancy. Very often, a miscarriage, an undeveloped pregnancy or a threat of miscarriage (bloody discharge from the genital tract, pain in the lower abdomen and lower back) appears precisely at this time. If this happens, the woman needs hospitalization. The hospital uses various medications to help keep the pregnancy, if possible.

So, as we have seen, the first trimester of pregnancy almost entirely consists of critical periods, so at this time it is especially important:
if possible, eliminate the negative impact of harmful production;
change the complex of physical exercises during active training in the period before pregnancy, postpone extreme sports for the postpartum period;
spend enough time outdoors;
enough time (8-10 hours) to sleep;
do not take an active part in the repair of premises;
give up bad habits especially such as alcohol, drugs, smoking.

fertile period

From 12 weeks of pregnancy, the fetal period of intrauterine life begins, which lasts up to 40 weeks. At this time, the fetus is already fully formed, but physically immature.

Pregnancy periods of 13, 20-24 and 28 weeks are critical for patients with hyperandrogenism - an increased content of male sex hormones - due to the onset of fetal hormone production. During these periods, it is necessary to check the level of hormones and adjust the dose of drugs that are prescribed to reduce the amount of male sex hormones (dexametlezone, metip-red, etc.). At the same time, the doctor monitors the condition of the cervix, since an increase in the amount of male sex hormones can lead to its premature opening.

At 13 weeks of pregnancy, the male fetus begins to produce its own testosterone - the male sex hormone, at 20-24 weeks the production of cortisol and male sex hormones by the adrenal cortex of the fetus begins, as a result of which a woman with hyperandrogenism may have another rise in male sex hormones, which will lead to termination of pregnancy.

At 28 weeks, the fetal pituitary gland begins to synthesize a hormone that stimulates the adrenal glands - adrenocorticotropic hormone, resulting in increased production of male sex hormones, which can also lead to termination of pregnancy. If necessary, the doctor will adjust the dose of medications at this time.

So, the action of adverse factors during critical periods of pregnancy can lead to the most adverse consequences. Therefore, a woman during the entire time of waiting for a child, and especially during critical periods, should avoid the action of adverse factors and consult a doctor in case of any “malfunctions”. I would like to advise expectant mothers to take care of themselves, especially since pregnancy lasts only 9 months, and the health and life of your baby depends on its course.

What should be cause for concern?

If the action of adverse factors at a critical time has led to the threat of termination of pregnancy, women complain of pain in the lower abdomen, in the lower back - pulling or cramping. Pain may be accompanied by bloody discharge from the genital tract. Such symptoms should not be left without due attention, because. following them, massive bleeding may occur due to incomplete spontaneous miscarriage, in which the pregnancy cannot be saved.

It is very important at the first symptoms of a threatened miscarriage to immediately contact a gynecologist, undergo the necessary studies, including an examination on the armchair, ultrasound, hormonal blood tests for female sex hormones, male sex hormones, thyroid hormones.

Jasmina Mirzoyan
Obstetrician-gynecologist,
cand. honey. Sciences, Moscow
Article provided by the journal
"9 months", 2006

The critical periods of the embryonic (intrauterine) period of development of the embryo and fetus are the most vulnerable periods of pregnancy, during which the laying of the baby's organs and systems takes place.

Embryonic (intrauterine) development of the embryo and fetus by week

It is during these periods of intrauterine (embryonic) development that the influence of teratogenic factors is most dangerous.

Factors that damage the fetus (teratogenic factors)

From the side of the environment:

• RADIOACTIVE RADIATION. When exposed to radiation in the pre-implantation period, when the embryo consists of only a few cells, as a rule, its death occurs and miscarriage. Malformations of the embryo at this stage are extremely rare. Malformations, according to the statement of the International Commission on Radiological Protection, can occur at a dose above 100 mGy and are most often manifested by disorders of the development of the central nervous system. During pregnancy, radiation therapy, taking into account the minimal risk to the health of the fetus, is possible with irradiation of tumors localized above the diaphragm: tumors of the brain, head, neck, breast, Hodgkin's lymphoma. Radiation therapy for cervical cancer is not compatible with fetal viability.
• ELECTROMAGNETIC RADIATION: being near working electrical appliances (computer system unit, monitor cathode ray tube, microwave oven, radiotelephone), living and / or working in the exclusion zone of power lines, etc.
• CHEMICAL AGENTS: benzene, aniline dyes, organophosphate fertilizers, chemotherapy during pregnancy, etc.

From the woman's side:

• Genetic and chromosomal ANOMALIES.
• INTOXICATIONS: the use of alcoholic beverages, narcotic drugs (drugs), low-quality food, etc. during the period of conception and pregnancy.
• ENDOCRINE diseases.
• INFECTIOUS diseases: rubella, toxoplasmosis, syphilis, herpes infection, influenza, etc.
• SOMATIC diseases (diseases internal organs), causing hypoxia (lack of oxygen supply): chronic heart failure, obesity, bronchial asthma etc.
• Increased drug load on the body of a pregnant woman, including the RECEPTION of MEDICINES prohibited for use before 12 weeks of pregnancy. According to research data for the period 1976-2008. the number of medications used during pregnancy has increased from 2.5 to 4.2 in the last 30 years. At the same time, the use of drugs in the first trimester of pregnancy (up to 12 weeks) increased by 63%.
• Excess intake of vitamins in the form of pharmaceuticals (pharmaceuticals). HYPERVITAMINOSIS is no less harmful than hypovitaminosis (vitamin deficiency). "Only in a sense of proportion is true good..."

Teratogenic (damaging the fetus) effect of vitamins

During pregnancy, there are periods that are critical for the development of the fetus. Also the highest is the threat of termination of the pregnancy itself, in other words, miscarriage. At this time, you should be extremely attentive to yourself, to the state of your health, in order to help the future baby feel comfortable in his first universe - his mother's tummy. Telling you in detail when you need to be careful and for what reasons is the main goal of our article.

"Critical periods" - what does it mean?

Pregnancy is one of the forms of coexistence of two organisms, two worlds, merging into a single whole: a woman and a child developing in her womb.

The successful course of pregnancy is ensured by the adaptation of the mother and the unborn child to each other. The thing is that the processes of this adaptation are very complex and at certain moments they function extremely intensely.

Critical periods of pregnancy, or critical periods in the development of the embryo and fetus, are those periods when their sensitivity increases, and adaptive capabilities decrease and the embryo becomes especially vulnerable.

These periods are characterized by active cellular and tissue processes and a significant increase in metabolism.

The effect of adverse environmental factors:
A) lack of oxygen (hypoxia),
B) hypothermia,
B) overheating
D) medicines
D) toxins
E) chemical products,
G) pathogens of viral and bacterial infections, etc.,

depending on the stage of development of the embryo, it can be extremely dangerous and even fatal for him.

So let's highlight each trimester has its own critical periods in parallel with the characteristic causes of abortion.

I trimester (from the first to the 15th week of pregnancy).

The first critical period falls on the 2-3rd week of pregnancy, when a woman may not yet assume that development begins in her body. new life . At this time, implantation of the fetal egg occurs, i.e. its introduction into the uterine mucosa. The implantation process may be disturbed:

• with anomalies in the structure of the uterus (infantilism, bicornuate or saddle uterus, the presence of a septum in the uterine cavity);
• with endometrial injuries, i.e. the inner layer of the uterus as a result of artificial abortions and inflammatory diseases (chronic endometritis);
• in the presence of uterine fibroids;
• with a scar on the uterus after caesarean section and other operations.

Another reason for abortion at the earliest stages is chromosomal and genetic abnormalities in the development of the fetus. There is a kind of natural selection of future offspring.

Besides, implantation can be prevented by any failures in the activity of the maternal organism, stress, anxiety, severe exercise stress . This and how to try to prevent the threat were discussed in the article “Threat of miscarriage - what to do?” .

And yet I would like to note once again that it is in the early stages that it is most vulnerable. Jobs like lifting heavy bags, moving furniture, or washing bulky items by hand are not for you right now. Even if the problem is the lack of helpers, some things can be done after childbirth. Not too fresh curtains on the windows will obviously endure a few more months before the change. The whole point is that you now realize that you yourself must endure them for the sake of yourself and the future of the crumbs.

I promise that after his birth, you will be so grateful to yourself that you did not once again take risks for the sake of maintaining perfect cleanliness and other beloved, but dangerous things!

The second critical period is 8-12 weeks of pregnancy.

During this period, the placenta begins to develop, and the main reason for interruption during these periods is hormonal disorders.

The main hormonal disorders leading to miscarriages:

• dysfunction of the ovaries,
• increased production of male sex hormones in the body of a woman,
• dysfunction of the thyroid gland.

Often, these hormonal disorders can occur simultaneously in one woman. In case of miscarriage, we are usually talking about erased forms of endocrine disorders that do not have distinct symptoms. Outside of pregnancy, these disorders, as a rule, do not manifest themselves in any way, but during pregnancy they lead to a violation of the mechanisms that ensure its preservation.

Ovarian dysfunction may be congenital or the result of abortion, inflammatory processes, or dysfunction of other endocrine glands. - pituitary gland, adrenal glands, thyroid gland. Most often, there is a lack of progesterone - the ovarian hormone necessary to maintain pregnancy in its early stages.

A decrease in progesterone levels leads to the threat of termination of pregnancy. In some cases, both the level of progesterone and other ovarian hormones, especially estrogen, may be initially reduced. The latter, in particular, affect the growth and development of the uterus. With a lack of estrogen, there is an underdevelopment of the uterus and its mucous membrane - the endometrium. After fertilization, the fertilized egg is introduced into the endometrium. If it is not developed enough, then the process of implantation of the embryo into the uterine wall may be disturbed, which leads to miscarriage.

An increase in the production of male sex hormones in a woman's body may be the result of an increased formation of male sex hormones (androgens) both in the ovaries and in the adrenal glands. . In any case, an increase in androgen levels leads to a decrease in estrogen levels and often causes a miscarriage or leads to a non-developing (“frozen”) pregnancy in the early stages.

Pregnancy

Thyroid dysfunction is often accompanied by ovarian dysfunction.

II trimester (from 15 to 27 weeks of pregnancy).

The critical period is 18-22 weeks of pregnancy.

1. Now the main cause of interruption are infectious diseases, sexually transmitted diseases.

The causative agents of infections:

• chlamydia,
• toxoplasma,
• ureaplasma
• herpes viruses, etc.,

insidious in terms of the possibility of impaired function of the placenta, infection of the membranes, premature outflow of water.

Attention! I will stop here specifically to say: please do not panic if you have one of the listed diseases, also called “latent infections”. Obstetric practice shows that great amount babies are born absolutely healthy if the mother has similar problems, and in reality there is every chance of a successful pregnancy outcome. If the disease could not be treated in advance (which mainly occurs in unplanned pregnancy), you can be treated now. There are drugs (including antibiotics) that are allowed during pregnancy and do not harm the fetus.

At this time, the uterus is actively growing. And there is a danger of anomalies in the location of the placenta, for example, low attachment.

Isthmic - cervical insufficiency.

The cervix during pregnancy serves as a kind of "constipation" that keeps the pregnancy in the uterine cavity.

Isthmic-cervical insufficiency is a pathology of the cervix, in which it is unable to perform this function. Under the influence of gravity, the fetal egg gradually descends, the cervix opens and ... the pregnancy is terminated.

To eliminate isthmic-cervical insufficiency, it is necessary to suture the cervix before the critical period. You should not be afraid at all, usually this manipulation is carried out after passing the necessary tests, with anesthesia.

From my own experience, I highly recommend, if possible, to purchase electronic scales. Not necessarily the most expensive. Pretty average for the price. They show the weight with an accuracy of 100 g and allow you to control the flow and flow of liquid. Weighing yourself in the evening and in the morning is what really helps. Thus, after buying the scales already at the 5th month, I stopped the sudden weight gain and swelling during the second pregnancy. As a result, the total weight gain was 14 kg, which is practically the norm. Now, two months after giving birth, I still have to lose another 3 kg to the initial weight - I lost 8 kg during childbirth, the remaining 3 kg - over the past two months ...

So, what can be said in the end?

Yes, early treatment of all diseases when planning a pregnancy is wonderful, but what if it didn’t work out and the pregnancy came?

Yes, a wonderful husband and a bunch of relatives who are always ready to help and free you from any work is just fine, but what if you have to deal with everything yourself for the most part?

Yes, an understanding boss is ready to free you from all harmful influences, stress, unnecessary work and let you go home earlier - this is generally super, but what if not ???

Of course, writing and even thinking about such serious things as the possibility of abortion, and various pathological conditions, forcing, to put it mildly, to worry future mother for the health of your child is not an easy task, and even more so far from pleasant.

But the important thing is that With timely treatment, many diseases and pathologies can be treated. available means and during pregnancy. If there is a lot of housework, then during critical periods try to distribute your forces, postpone or “drop” the most dangerous activities. With excessive stress at work, a clear knowledge of modern legislation that regulates the rights of pregnant women will help.

Knowledge in our age is a serious, powerful weapon that allows you to avoid much more difficult problems if you use it in time. And may you be all right!

Elena VLADIMIROVA