Having completed all its functions, it “retires.” What is the placenta, and why is monitoring its development as important as monitoring your baby's growth?

As soon as the nimble sperm reaches its desired goal, as soon as it begins to divide and grow, a completely new organ appears in your body along with the baby - the placenta, the connecting link between mother and child. After conception, the body produces enzymes that loosen the inner mucous membrane of the uterus, and a small cavity filled with blood appears in its wall - this is where the fertilized egg descends. From now on, she will receive oxygen and nutrition directly from the mother’s body, and after 12-16 weeks, the bodies of mother and baby will begin to communicate directly through the placenta - the baby’s first “house”. It will grow with your baby, satisfying all his vital needs.

Functions of the placenta

1. Connection
   The placenta connects mother and child, attaching one side to the walls of the uterus with the help of thin villi, and the other “side”, the vessels of the umbilical cord, to the child. Thus, it ensures close interaction between native organisms.
2. Barrier
   The placenta allows protective substances from the mother's blood to enter the baby's body, providing the baby with immunity. At the same time, it protects it from the penetration of some toxins, components of medications (not all), as well as aggressive antibodies from the mother. It prevents the mother’s body from perceiving the fetus as a foreign body and rejecting it. Unfortunately, the placental barrier is easily overcome by drugs, alcohol, nicotine, components of many medications and viruses.
3. "Air conditioner"
   Through one blood vessel of the placenta, oxygen enters the baby, and through the “neighboring” blood vessels, carbon dioxide is released into the mother’s body.
4. "Cook"
   Through the cells of the placenta, the woman's blood is filtered nutrients- in such a “ready” and easily digestible form they arrive to the baby. Through neighboring vessels of the placenta, the child “returns” into the mother’s blood everything that his body has not absorbed (waste products).
5. Security
   It is in the placenta that progestins, estrogens, and hCG hormones are produced, which are necessary for gestation of the fetus, its development and the normal course of pregnancy.

How the placenta develops

Before the development of the chorion, the precursor of the placenta, occurs. All the necessary hormones are still produced by the corpus luteum (the place where the egg used to be). The embryo is nourished by the resources of the egg.

The hormonal production of the corpus luteum begins to decline, and the developing placenta takes over its function. The embryo is nourished by the uterus.

The placenta takes on the function of controlling the metabolism of the mother's body, provoking in it the changes necessary for the life of the developing fetus. Toxicosis in the mother may intensify.

The embryo "becomes" the fetus. The formation of the placenta is not yet complete, but the baby receives nutrition from the mother’s blood.

The formation of the placenta ends. At this time, by determining the level of the hormone estriol in the urine, it is possible to evaluate the functioning of the fetoplacental complex (placenta-fetus system).

What doctors want to know about the placenta

Maturity level

This parameter, as doctors say, is “ultrasonic,” that is, it depends on the density of placental structures determined by ultrasound examination.

There are four degrees of placental maturity:

• normally, the zero degree of maturity of the placenta should be determined;
• the first degree is considered acceptable
• second - ;
• starting from the third degree of maturity of the placenta can be determined.

At the end of pregnancy, the so-called physiological aging of the placenta occurs, accompanied by a decrease in the area of ​​its exchange surface and the appearance of areas of salt deposition.

Place of attachment

Determined by ultrasound (see above for the location of the placenta in uncomplicated pregnancy).

Thickness

It is also determined through ultrasound examination - placentometry: after establishing the placenta attachment site, the area where it has largest size, which is determined. The thickness of this organ, as already mentioned, continuously grows to (by this time it ranges from 20 to 40 mm). Then its growth stops, and in the future it either decreases or remains at the same level.

We can fix everything

In anticipation of childbirth, expectant mothers associate all worries and fears primarily with the child, but the healthy state of the placenta, as the main “battery” for the developing fetus, is no less important. Often, pregnancy complications are associated specifically with the child's place. And yet you should not be afraid of abnormalities in the placenta: even if the doctor discovers any abnormalities in you, it is undoubtedly easier to correct the situation and influence this “temporary organ” than the child himself.

If your doctor suspects you...

• , this means that it is located at the bottom of the uterus, as if blocking the entrance (normally it should be located on one of the walls of the uterus).
  So what now? The baby is in no danger of such a deviation. The most important thing is not to provoke bleeding, which is where the uterus is located during placenta previa. Alas, you will have to postpone sexual activity, and also postpone visiting the sauna, taking hot baths and reduce to a minimum physical activity. IN maternity hospital It is better to go to bed 1-1.5 weeks before the expected date of birth.
  How will we give birth? Placenta previa can be partial or complete. When fully shown C-section. If the presentation is partial, then the decision about the operation is made by the doctor depending on how the placenta is located.
• Placenta accreta.
  The villi that attach the placenta to the walls of the uterus are usually connected to its inner mucous membrane, and at the time of birth they easily peel off from the walls. But it happens that they penetrate into deeper muscle layers. This anomaly is quite rare.
  So what now? You will have to limit physical activity and sex life.
  How will we give birth? Since such a diagnosis can most often be made only at the time of birth, the first periods proceed naturally, and in the third phase, after the baby is born, the obstetrician will have to separate the placenta manually. This is done under general anesthesia and you will not feel anything.
• Placental insufficiency.
  If the blood circulation of the mother's blood vessels is impaired, there is a risk that the baby will not receive the necessary nutrition and the placenta will not be able to fully protect him from harmful external influences. This diagnosis can be made from 8 weeks of pregnancy; diagnosed by ultrasound or Doppler study of blood vessels.
  So what now? To improve the blood supply to the fetus, mothers are recommended to take frequent and long walks, a set of exercises and a course of treatment (thermal procedures in the perinephric area, electrophoresis; taking vasodilators and beta-mimetics, heparin therapy). In addition, a diet rich in protein (fish, cottage cheese and dairy products, boiled meat) is prescribed.
  How will we give birth? Normally, naturally. However, be prepared for the fact that you will have to go into confinement and undergo a course of special therapy.
• Premature placental abruption.
  Any period that begins before the third phase of labor can be considered premature. It is diagnosed by a doctor based on the results of the study. Symptoms that you need to pay attention to are sharp pain in the lower abdomen, bleeding from the vagina, a sharp drop in temperature and pressure against the background of pallor, shortness of breath, sweating and increased heart rate. This pathology often has hereditary roots, so ask your mother if she had such a problem.
  So what now? You need to go to the hospital and undergo a course of therapy.
  How will we give birth? If it began during labor before the third stage, you will most likely be offered a cesarean section.
• Placental infarction.
  This term is also called necrosis, that is, necrosis of an area of ​​the placenta. In this case, its blood supply deteriorates, and the baby may not receive enough nutrition and oxygen.
  So what now? Medicines that improve blood circulation and additional nutrition will help activate the “working” areas of the placenta.
  How will we give birth? You need to prepare yourself psychologically for a caesarean section. When choosing a maternity hospital, focus on those with wards intensive care for newborns and the most modern equipment.
• Premature aging of the placenta.
  Towards the end of the placenta's function, it gradually weakens. Your baby is getting ready to be born, and his first “house” is reaching its end to go to “retirement.” But it happens that the aging process of the placenta begins too early, and it can no longer provide the child with all the necessary substances. Expectant mothers who smoke and are addicted to diets are prone to this.

So what now? In 9 cases out of 10, the doctor will send you for preservation. At home, if the placenta matures rapidly and wears out, you may be prescribed drug treatment(“Courantil”, “Trental”).

How will we give birth? In most cases, birth occurs naturally, but the aging placenta may begin to separate earlier due date, and then you will be offered a caesarean section.

During pregnancy in female body unique anatomical formations and even new organs appear. One of them is the placenta. Without it, it is impossible to imagine the development of a baby in the mother's womb. This article will tell you what the placenta is, how it is formed and what functions it performs.

Characteristic

The placenta is a special embryonic organ. It is characteristic not only of humans, but also of other mammals. The appearance of the placenta in the female body is impossible to imagine without chorion.

Its formation begins to occur after a fertilized egg is implanted into a specific wall of the uterus. Subsequently, a specific formation appears around it, which can be called chorion. Its membranes subsequently begin to transform and become placental tissue.

Scientists have found that the chorion first appears in the body of a pregnant woman within 7-12 days from the moment of fertilization. It takes some time to transform into a placenta. On average it is several weeks. The first formed placental tissue appears only at the beginning of the second trimester of pregnancy.

The placenta did not acquire its name by accident. This specific organ, formed only during pregnancy, has been known to doctors since ancient times. Agree that it is not difficult to notice. During childbirth, after the birth of the child, the birth of the placenta occurs. This feature contributed to the fact that the placenta was called the placenta for a long time. It should be noted that this name has been preserved to this day.

From Latin, the term “placenta” is translated as “cake”. This name almost completely characterizes the appearance of the placenta. It really does resemble a flatbread. Doctors often call the placenta also “the baby’s place.” This term is used quite often even in medical literature.

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Structure

The placenta of pregnant women has a heterogeneous structure. In fact, it is a unique organ that must perform a huge variety of different functions. Any disturbances in the structure of the placenta can be very dangerous due to the development of pathologies. The presence of defects in the structure of placental tissue causes a disruption in the course of normal intrauterine development fetus

To securely attach to the walls of the uterus, the placenta has special outgrowths - villi. Through them, reliable fixation of the placental tissue to the wall of the uterus occurs. This feature also determines the interaction between the small embryo, the placenta and the endometrium.

Between the placenta and the fetus there is an umbilical cord - this is a special organ that, in fact, connects the baby with his mother at the biological level. This unique connection will last until childbirth. Only after the baby is born is the umbilical cord cut, which means the birth of a new person.

The umbilical cord contains important blood vessels - arteries and veins. Outside, they are surrounded by a special substance - “Wharton’s jelly”. It has an interesting texture that resembles jelly. The main purpose of this substance is reliable protection blood vessels umbilical cord from exposure to various negative environmental factors.

In a normal pregnancy, the placenta remains in the female body throughout pregnancy. Her birth occurs after the birth of the baby. On average, the placenta is delivered 10-60 minutes after the baby is born. The difference in this time interval in different genera depends on many factors.

All placental tissue can be conditionally divided into 2 parts - maternal and fetal. The first is adjacent directly to the uterine wall, and the second is adjacent to the fetus. Each part of the placenta has a number of unique anatomical features.

Mother part

This zone of the placenta is formed largely on the basis of the decidua, or rather, its basal part. This feature determines the special density and structure of the maternal part of the placenta. The surface of this area of ​​placental tissue is quite rough.

The presence of special partitions that are present in the placenta ensures the separation of maternal and fetal blood flow. The placental barrier prevents mixing of the blood of mother and fetus at this stage. The specific “exchange” begins to occur a little later. This occurs due to the active process of osmosis and diffusion.

Fetal part

This part of the placenta is covered with a special amniotic layer. Such a structure is necessary so that subsequently a special aquatic environment is formed in the uterine cavity in which the baby will “live” for several months of its intrauterine development.

On the fetal side of the placenta there is a special chorionic formation, which ends in numerous villi. These villi participate in the formation of an important element - the intervillous space.

Some of the villi are called anchor villi, as they are tightly fixed to the uterine wall, providing reliable fixation. The remaining outgrowths are directed into the intervillous space, which is filled with blood from the inside.

Decidual septa (septa) divide the surface of the placental tissue into several individual parts- cotyledons. They can be called structural and anatomical units of the placenta.

The number of cotyledons changes as the placenta matures. When it finally matures, the total number of such structural and anatomical formations is several dozen.

Cotyledon

The main component of the placenta resembles appearance cup. Each structural and anatomical unit of placental tissue has a large branch of the umbilical blood vessel, which branches into several small branches.

This structure ensures a very important function of the placenta - blood supply to the fetus with all the necessary substances for its growth and development. The abundant blood mesh that covers the cotyledon provides blood flow to each individual area of ​​the placental tissue. This helps ensure an uninterrupted flow of blood not only to the placenta itself, but also to the body of an actively developing baby.

How is blood supply ensured?

This question is very important, since without uninterrupted blood flow the functioning of the placenta is impossible. The uterus, in which the baby develops, is nourished through the ovarian and uterine arteries. Doctors call them spiral vessels. The branches of the ovarian and uterine arteries are located in the intervillous space.

It is important to note that there is a pressure difference between the spiral vessels and the intervillous space. This feature is necessary for gas exchange and the provision of nutrients to occur. The pressure difference allows blood from the arteries to penetrate to the villi, wash them and then move to the chorionic plate. Then it enters the maternal veins.

This feature of blood flow ensures a certain permeability of placental tissue. It is believed that the ability to penetrate various nutrients and oxygen gradually increases with each subsequent day of pregnancy. By 32-34 weeks, placental permeability is at its maximum. Then it begins to gradually decrease.

Weight

During pregnancy, the size of the placenta changes almost constantly. So, at birth, a healthy placenta weighs on average about 0.5-0.6 kg. Its diameter in most cases is from 16 to 20 cm.

The thickness of the placenta may vary. This largely depends on individual characteristics, as well as on whether there are any pathologies in the formation of this organ. With each subsequent day of pregnancy, the thickness of the placenta increases.

Doctors believe that this increase ends only by 36-37 weeks of pregnancy. On average, after childbirth the thickness normal placenta is approximately 2-4 cm.

Type

Human placental tissue has a number of features that distinguish it from the placenta of other mammals. The human placenta is of the hemochorial type. This type of placental tissue is characterized by the ability of maternal blood to circulate around the villi, which contain fetal capillaries.

This structure of the placenta has interested many scientists. Already at the beginning of the 20th century, Soviet scientists conducted a number of scientific studies and made interesting developments based on the properties of placental tissue. Thus, Professor V.P. Filatov developed special pharmaceutical preparations that contain chemical composition extract or suspension of placenta.

Nowadays, science has greatly advanced. Scientists have learned to actively work with the placenta. Stem cells are isolated from it, which have a number of important functions. There are even cord blood banks where they are stored. Storing stem cells requires certain conditions and responsible compliance with a number of strict sanitary and hygienic rules.

For many years, scientists believed that the human hemochorial placenta was a sterile organ. However, numerous scientific studies have rejected this. Even in a healthy placenta after childbirth, some microorganisms are found, many of which live in the oral cavity of a pregnant woman.

How is it formed?

The formation of the placenta is a complex biological process. Scientists believe that the placenta is actively forming at 15-16 weeks of pregnancy. However, the period of final development of the organ may vary. Thus, only at the 20th week of pregnancy do blood vessels begin to actively function in the placental tissue.

In most cases, the placenta forms in the posterior wall of the uterus. Placental tissue is formed with the participation of a special embryonic formation - the cytotrophoblast and the endometrium itself (the inner lining of the uterine wall).

The final histological structure of the placenta became known to doctors relatively recently - in the era of microscopic studies. In placental tissue, scientists distinguish several sequential layers:

• Decidua– the first layer in the direction from the uterus to the embryo. In essence, it is a modified endometrium.
• Langhans layer(Rohr fibrinoid).
• Trophoblast. This layer covers the lacunae and grows into the walls of the spiral arteries, which prevents their active contractions.
• Numerous gaps which are filled with blood.

• Multicore simplast, lining cytotrophoblast (syncytiotrophoblast).
• Cytotrophoblast layer. It is a layer of located cells that form a syncytium and produce the formation of certain hormone-like substances.
• Stroma. It is a connective tissue in which blood supply vessels pass. Also in this layer there are very important cellular elements - Kashchenko-Hoffbauer cells, which are macrophages and provide local immunity.
• Amnion. Participates in subsequent education amniotic fluid. It is necessary for the formation of a special aquatic environment in which the baby’s intrauterine development will take place.

A very important structural element of the placenta is its basal decidua. It is a kind of barrier between the maternal and fetal parts of the placenta. In the area of ​​the basal decidua there are numerous depressions, inside of which maternal blood is present.

Functions

The placenta plays a very important role during pregnancy. The number of functions performed by this body is quite large. One of the most important of them is the protective or barrier function. The placenta participates in the formation of the hematoplacental barrier. It is necessary to ensure that the intrauterine development of the fetus is not disrupted.

The following anatomical units participate in the participation of the blood-placental barrier:

• cell layer of the endometrium (inner wall of the uterus);
• basement membrane;
• loose pericapillary connective tissue;
• trophoblast basement membrane;
• cytotrophoblast cell layers;
• syncytiotrophoblast.

Such a complex structure is necessary for the hematoplacental barrier to provide important functions placenta. Violation of the histological structure can be dangerous. In such a situation, the placental tissue simply will not be able to fully function.

Participation in gas exchange

Through blood vessels that large quantities are in the placental tissue, the fetus receives oxygen and also “gets rid” of carbon dioxide.

This happens through ordinary simple diffusion. At the same time, oxygen penetrates into the body of an actively growing baby, and waste carbon dioxide is released. This kind of “cellular respiration” occurs throughout the entire period of pregnancy. This unique mechanism develops due to the fact that the fetal lungs form quite late.

A child in the mother's womb does not breathe on its own. He will take his first breath only after birth. In order to compensate for this condition, such cellular gas exchange occurs.

Providing food

Despite the fact that by a certain stage of pregnancy the baby’s mouth and organs are formed digestive system, he still cannot eat on his own. All the nutritional components that a child’s body needs for birth are received through the blood vessels. Proteins, fats and carbohydrates enter the baby's body through the arteries of his mother. In the same way, the baby receives water, vitamins and microelements.

This feature of fetal nutrition clearly explains why the diet of a pregnant woman is very important. For full intrauterine development of the fetus expectant mother should carefully monitor what foods she consumes during the day.

It is very important that a pregnant woman's diet regularly includes fresh fruits and vegetables, as well as high-quality sources of protein.

Isolation of unnecessary metabolic products

The kidneys and excretory system of the fetus begin to function quite late. While they are not yet well formed, the placenta comes to the rescue. Through the placental tissue, unnecessary metabolites waste by the child’s body are removed. Thus, the fetal body “gets rid” of excess urea, creatinine and other substances. This process occurs through active and passive transport.

Hormone synthesis

The hormonal function of the placenta is perhaps one of the most important. During pregnancy, placental tissue is even an organ of internal secretion, as it participates in the formation of biologically active substances.

One of them is the most important pregnancy hormone - human chorionic gonadotropin. It is necessary for the normal course of pregnancy. This hormone ensures the proper functioning of the placenta and also stimulates the formation of progesterone in the body of a pregnant woman. It is necessary during pregnancy in order to stimulate the growth of the endometrium and temporarily stop the maturation of new follicles in the ovaries.

With the participation of the placenta, placental lactogen is also formed. This hormone is necessary in order to prepare the mammary glands for the upcoming changes - lactation. Under the influence of the placenta, another hormone necessary during pregnancy is formed - prolactin. It is also necessary in order to prepare the mammary glands of the expectant mother for the upcoming lactation.

Scientists have discovered that placental tissue can synthesize some other hormones - testosterone, relaxin, serotonin and others. In addition to the active synthesis of hormones, placental tissue is also involved in the formation of hormone-like substances that are necessary for the normal course and development of pregnancy.

Fetal protection

This function of the placenta can be divided into several types. So, it can be mechanical and immune. Each of them is very important during the period of intrauterine development of the fetus.

Mechanical protection of the fetus involves protecting the child’s body from any influences of the external environment. Placental tissue is a very delicate structure. It is located in close proximity to the fetus. In case of various injuries, the placenta seems to “soften” the blow. This helps reduce the risk of harm to the fetus.

The immune protective function of the placenta is that The placenta is involved in providing the child's body with maternal antibodies. These special substances provide immunity to the fetus throughout its entire intrauterine life in the mother's womb.

Antibodies that enter the baby’s body from his mother through the blood are immunoglobulins. Some of them quietly penetrate the placenta, entering the child’s body. Thus, the placenta helps protect the baby from a number of bacterial and viral infections.

The entry of maternal antibodies also helps to prevent an immunological conflict between mother and fetus. In this case, the maternal body does not perceive the fetus as a foreign genetic object. This feature helps prevent rejection of the fetus from the uterine cavity throughout pregnancy.

It should also be noted about the special role of syncytium - a special element of placental tissue. It is involved in the absorption of a number of dangerous chemicals, which can cross the placenta from mother to fetus. Thus, the placenta, as it were, protects the baby’s body from the penetration of dangerous narcotic, toxic and other dangerous substances into it.

It is important to remember that such selectivity of penetration can be individual. If the histological structure of the placenta is normal, then hazardous substances are retained. If it is violated, then toxins and poisons can easily penetrate the child’s body, causing irreparable harm to it. That is why doctors recommend that expectant mothers give up all bad habits during pregnancy.

Smoking and drinking alcohol, as well as drugs, can cause the development of dangerous diseases in an actively developing fetus. Preventing their development is much easier than trying to cope with emerging pathologies in the future.

Maintaining healthy image The life of the expectant mother is of great importance in the formation and normal functioning of the placenta.

Migration

The initial position of the placenta in the uterine cavity is a very important clinical indicator. Even the course of pregnancy depends on how it is positioned.

Typically, placental tissue is attached to the back or front wall of the uterus. It is extremely rare that it is attached only to one of the side walls. The laying of placental tissue begins in the first trimester of pregnancy and is associated with the site of implantation of the fertilized egg.

Normally, a fertilized egg attaches to the fundus of the uterus. There is good blood flow in this zone, which is necessary for the full intrauterine development of the fetus throughout pregnancy. However, this situation does not always develop.

In obstetric practice, cases are recorded when implantation of a fertilized egg occurs in the lower parts of the uterus. This is preceded by a huge number of different reasons. In this case, the fertilized egg can descend almost to the base of the internal uterine os, where it attaches to the uterine wall.

The lower the implantation occurs, the lower the placenta is located. Doctors call the growth of placental tissue on the area of ​​the internal uterine pharynx previa. This dangerous pathology significantly worsens the course of pregnancy and can even cause the development of dangerous complications.

The original location of the placental tissue may change. Most often this occurs in cases where the placenta is attached to the anterior wall of the uterus. The process of changing the original location of placental tissue is called migration. In this case, the placenta shifts, as a rule, from bottom to top. Thus, if a low position of placental tissue was identified in the first half of pregnancy, it may still change.

Typically, the process of placenta migration proceeds quite slowly - within 6-10 weeks. It ends completely, as a rule, only by the middle of the 3rd trimester of pregnancy.

The placenta, located on the back wall of the uterus, practically does not migrate. The likelihood of placental tissue displacement in this position is extremely low. This is largely facilitated by certain structural features of the uterus.

Norm

A healthy placenta is an important part of a normal pregnancy. The development of this unique pregnancy organ occurs gradually. From the moment it is formed in the female body until childbirth, the placenta changes almost constantly.

Doctors can evaluate the anatomical properties of the placenta, as well as identify various anomalies in its development, by performing ultrasound examinations. To do this, the expectant mother must undergo several ultrasound scans throughout her pregnancy.

With the help of modern devices, specialists can obtain fairly clear visualization of placental tissue. During an ultrasound examination, the doctor can see the structure of the placenta, the presence of any diffuse changes in it, as well as emerging pathologies.

A very important clinical indicator that obstetricians-gynecologists must determine during pregnancy is the maturity of the placenta. It changes at each stage of pregnancy. This is quite normal. In this case, it is important to assess the correspondence of the maturity of the placenta to a certain stage of pregnancy.

Thus, experts identify several options for the maturity of placental tissue:

• Zero (0). Characterizes the normal structure of the placenta until approximately 30 weeks of pregnancy. The placenta of this maturity has a fairly smooth and even surface.
• First (1). Characteristic of a healthy placenta from 30 to 34 weeks of pregnancy. With first-degree maturity, specific inclusions appear on the placenta.
• Second (2). Forms normally after 34 weeks of pregnancy. Such placental tissue already looks more prominent, specific striations appear on it, as well as small grooves.
• Third (3). Is the norm for a normal full-term pregnancy. A placenta with this degree of maturity has quite pronounced large waves on its surface that reach the basal layer. Also, on the outer surface of the placental tissue, spots that merge with each other and have an irregular shape appear - salt deposits.

Determining the degree of maturity of the placenta allows doctors to navigate the timing of the upcoming birth. In some cases, placental tissue matures too quickly. This leads to the development of a number of dangerous complications. In this case, pregnancy management tactics must be reviewed by specialists.

Pathologies

Unfortunately, anomalies in the development and formation of the placenta occur quite often in obstetric practice. Such conditions significantly worsen the prognosis of pregnancy. Emerging defects in the structure of the placenta also contribute to the deterioration of blood flow, which is necessary for the full intrauterine development of the baby.

Currently, quite a few different pathologies of the placenta are known. One of the most dangerous of them is a strong accretion of placental tissue to the uterine wall. It would seem that the more the placenta “grows” into the endometrium, the more reliable the fixation should be, but in fact this is not entirely true.

Strong accretion of the placenta to the uterine wall is dangerous due to the development of problems with its separation during childbirth. In such a situation, the birth of the child, as a rule, proceeds normally, but the birth of the placenta is delayed. This clinical situation can be dangerous due to the development of massive uterine bleeding.

Also, prolonged presence of the placenta in the uterine cavity poses a threat of infection of the reproductive organs.

If there is a strong accretion of placental tissue to the wall of the uterus, surgical gynecological intervention is required. In this situation, doctors purposefully separate the placenta from the uterine walls.

Quite often, scars form on the uterus. This usually happens in cases where various surgical operations– caesarean section, excision of damaged tissue and others. A strong proliferation of connective tissue leads to the formation of scars.

Placenta accretion into the uterine scar is a rather dangerous pathology. In this case, during natural birth Dangerous complications may arise. In order to avoid them, doctors are often forced to resort to surgical obstetrics - caesarean section.

A strong descent of the placenta to the level of the internal os is dangerous due to the development of its presentation. This pathology worsens the prognosis of pregnancy. With placenta previa, the risk of developing dangerous infectious diseases and premature birth is quite high. In order to preserve and prolong pregnancy as much as possible, the expectant mother must strictly follow the recommendations made for her by doctors.

Placental abruption is another dangerous pathology that occurs in obstetric practice. It is characterized by detachment of placental tissue for certain reasons from the walls of the uterus. In this case, as a rule, bleeding develops. If placental abruption occurs over a fairly large area, then this situation is extremely dangerous for the life of the fetus. Massive detachment of placental tissue, accompanied by the occurrence of functional disorders in children's body, may be an indication for an emergency caesarean section.

Another dangerous pathology is placental edema. A variety of causes can lead to the development of this condition, including bacterial and viral infections. Prolonged swelling of the placenta can lead to the development of fetoplacental insufficiency, fetal hypoxia, and also provoke premature birth. When this pathology is detected, doctors carry out complex treatment.

The placenta contains quite a few blood vessels. The placental tissue surrounding them is quite loose and tender. Strong mechanical stress can cause small microdamages and even tears to appear in it. As a rule, such minor injuries do not manifest themselves clinically for a long time.

If the ruptures in the placental tissue are quite significant, then this will contribute to disruption of its functioning. In this case, the general condition of the fetus may be affected. Impaired blood supply can affect the baby’s heart rate increase, as well as an increase in oxygen deficiency in his blood.

Defects and small hemorrhages in the placenta can only be detected with the help of modern ultrasound examinations. Minor damage, as a rule, is determined retrospectively - after birth during a visual examination of the placenta.

Structural changes can also be determined using histological examination, which is performed after birth. To conduct this examination, the placenta is sent to a special laboratory, where it is studied.

About what a placenta is, see the following video by Larisa Sviridova.

When a woman is pregnant, she may wonder what the placenta is, what the placenta is for and its role, and what factors can affect the placenta. Below we will talk in detail about this important organ of the embryo.

What is the placenta in pregnant women

In pregnant women, the placenta is an organ that grows in the uterus during pregnancy. The role of the placenta is to provide your unborn baby with a blood supply separate from yours, as well as provide nutrients and oxygen.

Why is the placenta needed during pregnancy?

Oxygen and nutrients pass from your blood supply to the placenta. From there, the umbilical cord carries oxygen and nutrients to your unborn baby. Waste from the baby, such as carbon dioxide, travels back from the umbilical cord to the placenta and then into your bloodstream for your body to get rid of.

The placenta produces hormones that help your baby grow and develop. The placenta during pregnancy also provides some protection against infection for your baby while it is in the uterus, protecting it from most bacteria. However, it does not protect your child from viruses.

When the placenta is not working, it cannot provide enough oxygen and nutrients to the baby from the mother's bloodstream. Without this vital support, a child cannot grow and develop. This may lead to decreased birth weight, premature birth and birth defects. It also carries an increased risk of complications for the mother. Early diagnosis of this problem has important for the health of mother and child.

Alcohol, nicotine and other drugs can also harm the placenta and may harm your unborn baby.

Below is a list of the most common problems with the placenta and its changes during pregnancy

Placenta I Placenta (lat. placenta cake; synonym)

developing in the uterine cavity during pregnancy, establishing a connection between the mother’s body and the fetus. Complex biological processes occur in the placenta that ensure the normal development of the embryo and fetus, the synthesis of hormones, protection of the fetus from harmful factors, immune regulation, etc. The placenta plays a leading role in the normal functioning of the fetoplacental system (Fetoplacental system), from early pregnancy to childbirth. After the birth of the fetus, P. is rejected from the uterine cavity.

Formation, structure, topography. After ovulation, the egg enters the fallopian tube; it is covered with a structureless transparent membrane (zona pellucida) and several layers of follicular epithelial cells forming (corona radiata). occurs in the ampulla of the fallopian tube or in abdominal cavity. Under the influence of enzymes secreted by the epithelium of the fallopian tube, the fertilized (unicellular) tube is freed from the cells of the corona radiata. During passage through the fallopian tube (3-4 days), the fertilized egg divides into blastomeres, and a multicellular embryo enters the uterus (). The blastomeres of the outer layer of the morula form, and those located inside -. From the former, P. develops with amnion and chorion (see Membrane), from the latter - Fetus. A small cavity filled with fluid forms between the trophoblast and embryoblast: the embryo at this stage of development is called a blastocyst. at the end of the 1st - beginning of the 2nd week after fertilization, it is immersed (implanted) into the thickness of the endometrium. in the endometrium, after the blastocyst is immersed in it, it is covered with proliferating epithelium. At the time of implantation, it is in the middle stage of the secretory phase of the menstrual cycle. In its functional layer, two zones are clearly distinguished: spongy (spongy) with a large number vessels and glands secreting, rich in acidic mucoids, glycoproteins and glycogen, and compact (superficial) with a small number of glands and a large number of large connective tissue cells containing.

After implantation, the functional layer of the endometrium thickens, its glands are even more filled with secretions, the connective tissue cells of the compact zone increase, and the amount of glycogen, lipids, vitamin C, nonspecific esterases, acid and dehydrogenase increases in them. Initially, these changes are most pronounced at the site of implantation, then spread to the entire endometrium. The functional layer of the endometrium, modified in connection with pregnancy, is called the decidua (falling off) membrane. There are several parts in the decidua: basal, located between the fertilized egg and the wall of the uterus; capsular, covering the fetus from the side of the uterine cavity; parietal, lining the entire inner surface of the uterus, with the exception of the area of ​​attachment of the fertilized egg (see. rice. 2 to the article Pregnancy).

As the blastocyst sinks into the endometrium, its outer layer (trophoblast) grows and becomes multilayered. Then primary villi are formed on its surface, consisting only of trophoblast cells (). As a result of the disintegration of the endometrium under the influence of proteolytic enzymes of the trophoblast, an embryotroph is formed, which is resorbed by the trophoblast and used to nourish the embryo. By this time, the outer layer of trophoblast in the primary villi becomes cell-free (plasmoid). Primary villi face cavities - lacunae, which arise at the site of the breakdown of blood vessels and connective tissue of the endometrium. The combination of these lacunae forms, filled with maternal blood from the vessels of the basal decidua.

By the 12-13th day of development, the embryo grows into the primary villi located on the surface of the chorion facing the myometrium - secondary trophoblast villi are formed. At the 3rd week of embryo development, vessels (fruit) begin to grow into the stroma of the secondary villi - tertiary villi are formed; this process is called placentation. tertiary villi consists of two layers. Its outer layer is formed by syncytium, the inner layer by cytotrophoblast (Langhans cells), located on the basement membrane separating the trophoblast from the villus stroma. It is a continuous cell-free layer of cytoplasm with oval or round nuclei. The surface of the syncytium is covered with numerous microvilli. increase the resorption surface of the syncytium a thousand times. in the first trimester of pregnancy it consists of a continuous layer of large, round, closely adjacent cells. In II and especially in III trimesters During pregnancy, the cytotrophoblast is represented by single cells, larger than in the first trimester of pregnancy. Syncytium and cytotrophoblast are the chorionic epithelium of the villi. The tertiary villi consists of cellular elements (fibroblasts and macrophages), collagen fibers and fruit capillaries.

Tertiary villi develop on the surface of the chorion adjacent to the richly vascularized basal decidua; this part of the chorion is called the villous (branched) chorion. The villous amnion with the amnion covering it forms the fetal part of the P. On the surface of the chorion, facing the capsular decidua, the villi atrophy (smooth chorion).

Some large tertiary villi are closely attached to the basal decidua - anchor, or stem, villi. The remaining, smaller villi are freely located in the intervillous space (terminal villi) and are resorption in their function. By the end of pregnancy, the number of terminal villi and fetal capillaries in their stroma increases significantly, the chorionic one becomes thinner - single Langhans cells remain under the syncytium. In this case, it is directly adjacent to the basement membrane, and the fruit capillaries approach it and the syncytium (syncytiocapillary membrane). The basal part of the decidua with the septa extending from it forms the maternal part of the placenta.

From the moment of formation of tertiary villi, the transition from histotrophic nutrition of the embryo (due to the embryotroph) to hemotrophic nutrition begins. This transition ends by 16-18 weeks of pregnancy. By this period, the tertiary villi and the final formation of the placenta are completed.

Mature placenta ( rice. 1 ) is shaped like a round cake or a disk thinned along the edge. It is usually located on the back or front wall of the uterus, sometimes partially extending onto the side walls or bottom of the uterus. IN early dates pregnancy P. often reaches the internal uterine pharynx, but in most women subsequently, as the uterus grows, it rises upward. With a normal full-term pregnancy and fetal weight 3300-3400 G P. diameter is 17-20 cm, thickness 2-2.5 cm, weight 500 G. There are two P. surfaces: the fruit surface, facing the fetus, and the maternal surface, adjacent to the wall of the uterus. The fruiting surface of P. is covered with amnion - a smooth, shiny, grayish shell; The umbilical cord is attached to its central part, from which the vessels diverge radially. The maternal surface of P. is dark brown, divided into 15-20 segments - cotyledons.

Cotyledons are separated from each other by septa P. Each cotyledon has an autonomous vessel of the fetus; it contains two or more stem villi and their numerous branches. From the umbilical arteries, the deoxygenated fetus enters the vessels of the villi (fetal capillaries), from the fetal blood it passes into the maternal blood, which enters the intervillous space from the endometrial arteries (spiral-shaped arteries of the spongy zone of the decidua), and from the maternal blood it passes into the fetal capillaries. Oxygenated fetal blood from the cotyledons collects towards the center of the fetus and then enters the umbilical vein. Deoxygenated maternal blood flows from the intervillous space into the endometrial veins, which are scattered throughout the surface of the basal decidua. The circulation diagram of fetal and maternal blood in the placenta is presented in rice. 2 . Maternal and fetal blood do not mix; between them there is a blood cell consisting of the endothelium of the fetal capillaries, stroma and chorionic epithelium of the tertiary villi.

Physiology. P.'s functions are multifaceted and aimed at maintaining pregnancy and normal fetal development. In the syncytium, an intensive process of breakdown of products that are absorbed from the maternal blood circulating in the intervillous space occurs. From the metabolites of maternal products, various substances necessary for the fetus are actively synthesized. In the first trimester of pregnancy, this synthesis occurs mainly in the trophoblast, in the second and third trimesters - both in the trophoblast and in the fetal organs. Metabolic processes in the placenta are especially high in the 1st trimester of pregnancy. The placenta retains its functions throughout childbirth, ensuring the normal condition of the fetus. P.'s separation from the walls of the uterus and from its cavity occurs in the third stage of labor. Respiratory P. is carried out by transferring oxygen from maternal to fetal blood and carbon dioxide from fetal to maternal blood, depending on the needs of the fetus. P. (chorionic, placental lactogen, estrogens, etc.) ensure the normal course of pregnancy, regulate the most important vital functions of the pregnant woman and the fetus, and participate in the development of the birth act.

In addition, P. performs a protective function. Mainly in the syncytium and in the stromal cells of the villi, with the help of enzymes, exogenous and endogenous (formed in both the mother’s body and the fetus’ body) harmful substances are destroyed. Decay products are released into the intervillous space. P.'s barrier function depends on its permeability. The degree and rate of transition of substances through the P. are determined by various factors, including the area and thickness of syncytiocapillary membranes devoid of microvilli, the intensity of uteroplacental blood flow. P. increases until the 35th week of pregnancy due to an increase in the area and thinning of syncytiocapillary membranes, an increase in perfusion pressure, and then decreases due to aging of the P. With gestosis (late), isosensitization, and some endocrine and infectious diseases, the P. becomes more permeable, in incl. and for harmful substances than during physiological pregnancy. In this case, the risk of antenatal pathology of the fetus sharply increases, and the outcome of pregnancy and childbirth, the condition of the fetus and newborn depend on the degree and duration of action of the damaging factor and on the nature of the compensatory and adaptive reactions of the fetoplacental system.

The ability of various substances to pass through the P. largely depends on their chemical properties: molecular weight, solubility in lipids, ionization, etc. Substances with a low molecular weight penetrate through the membrane more easily than those with a high molecular weight (the lowest molecular weight is for substances with a molecular weight above 1000), those soluble in lipids - more easily than those soluble in water . P.'s permeability for ionized substances is significantly less than for non-ionized ones.

Of particular importance for practical obstetrics is P.’s permeability to medicinal substances. The degree of passage of the drug through the P. is assessed by calculating the placental permeability index (PPI).

The PPI for various medicinal substances varies widely - from 10 to 100%. For penicillin group drugs it is 25-75%. Administration of penicillin during pregnancy does not cause embryo- or fetopathies. High doses of ampicillin can lead to the development of kernicterus in the fetus. Streptomycin penetrates into a significant amount, the PPI for it is 80%. Long-term administration of this antibiotic in the 3rd-5th month of pregnancy contributes to damage to the fetal hearing system and can lead to congenital deafness, and therefore it should not be prescribed to pregnant women. PPI for kanamycin and gentamicin is about 50%; the toxic effect of these drugs on the hearing of the fetus is much weaker than streptomycin. The PPI for tetracycline antibiotics reaches 75%; these drugs have teratogenic properties and are contraindicated during pregnancy. The PPI for cephalosporins and erythromycin is 25-50%; these do not have a harmful effect on the fetus. pass well through P.; long-acting drugs actively bind to fetal blood plasma albumin, which can lead to the development of kernicterus; Taking them during pregnancy is not recommended.

Glucocorticoid hormones quickly bind to the blood proteins of a pregnant woman and, having passed through the fetus, are actively destroyed in the liver of the fetus, and therefore do not pose a danger to it. Sex hormone preparations easily pass through P. and do not have a harmful effect on the fetus (endogenous sex hormones in the blood of a pregnant woman and P. are hundreds of times higher than outside pregnancy). The exception is diethylstilbestrol, which is chemically related not to steroids, but to stilbenes. This can cause the development of adenosis of the vagina and cervix in girls whose mothers took it during pregnancy. Synthetic ones can have an adverse effect on the fetus. Thus, long-term use in the first trimester of pregnancy of large doses of norsteroid derivatives (pregnin, norkolut, etc.) can lead to virilization of the external genitalia in female fetuses: enlargement of the clitoris, fusion of labioscrotal folds. , which has a high molecular weight, does not penetrate through P.

Direct-acting anticoagulants () do not pass through the P. and do not affect the fetal coagulation system, while indirect-acting anticoagulants, penetrating through the P., cause hypocoagulation in the fetus, which prevents their use during pregnancy. Of the narcotic drugs, only sombrevin is quickly inactivated by the cholinesterase system of the pregnant woman and the fetus and can be used during pregnancy. Gaseous narcotic substances (ether, nitrous oxide), narcotic substances (morphine, fentanyl, etc.), penetrating through the fetus, suppress the respiratory function of the fetus to varying degrees.

Depolarizing muscle relaxants (ditilin) ​​are poorly soluble in lipids and have a high degree of ionization, as a result of which their passage through the P. is difficult. In contrast, non-depolarizing muscle relaxants (tubocurarine chloride, diplacin) pass through the P. more easily and can cause relaxation of skeletal muscles and in the fetus. , used to treat epilepsy (diphenin, trimethine, hexamidine, etc.), pass through the P. and cause a disturbance in the development of the central nervous system, skull and face of the fetus, and therefore they are not recommended to be prescribed in the first trimester of pregnancy.

Research methods. The place of attachment, size, and structure of the P. during pregnancy are determined using ultrasound (see Ultrasound diagnostics, in obstetrics and gynecology) and (less often) radionuclide studies. P.'s functional activity is judged by the level of excretion of human chorionic gonadotropin and estrogens in the urine, and by the content of placental lactogen, human chorionic gonadotropin and estrogens in the blood.

To determine signs of placental separation in the third stage of labor, special techniques are used (see Childbirth). After the placenta is isolated from the uterine cavity, P. is carefully examined, measured, weighed, and, if necessary, histological examination is carried out.

Pathology. P. hypoplasia is considered to be a decrease in its size compared to normal for a given fetal weight. With an average weight of a full-term fetus, P. hypoplasia is said to exist if its weight is less than 400 G, and the diameter is less than 16 cm. The causes of P.'s hypoplasia are impaired implantation in case of endometrial deficiency; embryotoxic factors (some medicines, chemical poisons, etc.) acting in the first trimester of pregnancy; vascular disorders (late toxicosis of pregnancy, hypertension). P. with its hypoplasia is reduced, which leads to fetal malnutrition. With significant hypofunction of the fetus, fetal death may occur.

In case of full-term pregnancy and average fetal weight, a fetus weighing more than 700 is considered hyperplastic. G and diameter more than 20 cm(at large fruit such an increase in P. cannot be considered as hyperplasia). P. can be increased in case of hemolytic disease of the fetus (in this case, the P. is swollen, but its villi are underdeveloped), endometrial inferiority after abortion (P. increases compensatoryly), and venous stagnation.

Anomalies in the shape of the placenta are possible. There are membranous, cingulate, multilobar placenta, placenta with additional lobules, etc. Membranous placenta has a thin-walled sac with a thickness of 0.3-0.5 cm lining most of the uterine cavity. Belt P. is a strip 20-23 long cm and width 4-6 cm. With membranous and zonular P., fetal development may be disrupted. Two- and three-lobe P., a placenta with additional lobules, as a rule, do not lead to disturbances in the condition of the fetus. Additional can linger in the uterus and lead to uterine bleeding in the postpartum period.

During complicated pregnancy (preeclampsia, etc.) and extragenital diseases of the mother, dystrophic and compensatory changes occur in the pregnancy. Dystrophic changes in placental tissue are preceded by hemodynamic disturbances: hemorrhages in the intervillous space ( rice. 3, a ), plethora of vessels in the stroma of stem villi ( rice. 3, b ) etc. Then dystrophic changes are detected with the formation of pseudoinfarctions (dystrophically changed villi surrounded by fibrinoid), sclerosis of the villous stroma ( rice. 4, a ), deposition of calcium salts ( rice. 4, b ). Along with this, compensatory-adaptive reactions are observed: for example, capillaries and the development of syncytiocapillary membranes in the terminal villi ( rice. 5, a, b ), syncytia of terminal villi with the formation of syncytial nodules ( rice. 5, in ), an increase in the number of small terminal villi.

In the edematous form of hemolytic disease of the fetus, the fetus is swollen, with hemorrhages (Fig. 6), foci of necrosis (Fig. 7) and calcification are often found in it, the villi are underdeveloped (few fruit capillaries, their immature, etc.).

Inflammatory changes that occur during hematogenous and ascending infection are manifested by leukocyte infiltrates in the amnion (), chorion (chorionitis), decidua () or in all parts of the pancreas ().

Subamniotic cysts and placental septal cysts can be found in the placenta. As a rule, along with P.'s cysts, dystrophic changes are observed, in particular white infarctions.

Developmental anomalies, dystrophic and inflammatory changes in the liver can lead to placental insufficiency. P. may be located in the area of ​​the internal uterine os (see Placenta previa). In some cases, there are anomalies of its attachment - tight attachment or true accretion (see Childbirth). One of the complications of pregnancy is premature abruption of a normally located placenta (see Premature placental abruption). P.'s pathology also includes choriocarcinoma (see Trophoblastic disease).

Bibliography: Kiryushchenkov A.P. and Tarakhovsky M.L. The influence of drugs on the fetus, M., 1990; Radzinsky V.E. and Smalko P.Ya. placental insufficiency, Kyiv, 1987, bibliogr.; Serov V.N., Strizhakov A.N. and Markin S.A. Practical, p. 58, 233, M., 1989.

Rice. 4b). Microscopic specimen of a dystrophically altered placenta during full-term pregnancy: deposits of calcium salts (indicated by arrows); hematoxylin and eosin staining; ×65.

a nodule in the terminal villus (indicated by an arrow); hematoxylin and eosin staining; ×250">

Rice. 5c). Microscopic specimen of a placental area with compensatory and adaptive changes during full-term pregnancy: syncytial nodule in the terminal villus (indicated by an arrow); hematoxylin and eosin staining; ×250.

umbilical cord is swollen, with hemorrhages">

Rice. 6b). Placenta with edematous form of hemolytic disease of the fetus: the fetal surface of the placenta is pale, the umbilical cord is edematous, with hemorrhages.

movement of maternal blood; 1 - umbilical cord, 2 - umbilical vein (oxygenated blood), 3 - umbilical arteries (deoxygenated blood), 4 - , 5 - smooth chorion, 6 - parietal, 7 - basal decidua, 8 - , 9 - endometrial veins, 10 - endometrial arteries, 11 - placental septum, 12 - placental villi (on the right - in the section), 13 - attachment of the anchor villi to the basal decidua. Oxygenated blood is shown in red, deoxygenated blood is shown in purple: the arrows indicate the direction of blood movement">

Rice. 2. Schematic representation of the circulation of fetal and maternal blood in the placenta (in section): I - circulation of fetal blood in the placental villi, II - circulation of maternal blood in the intervillous space, III - direction of movement of maternal blood; 1 - umbilical cord, 2 - umbilical vein (oxygenated blood), 3 - umbilical arteries (deoxygenated blood), 4 - amnion, 5 - smooth chorion, 6 - parietal decidua, 7 - basal decidua, 8 - myometrium, 9 - veins endometrium, 10 - endometrial arteries, 11 - placental septum, 12 - placental villi (on the right - in the section), 13 - attachment of the anchor villi to the basal decidua. Oxygenated blood is shown in red, deoxygenated blood is shown in purple: arrows indicate the direction of blood movement.

Probably each of us has heard about the placenta, but usually even pregnant women have a very general idea of ​​its purpose and function. Let's talk about this amazing organ in more detail.

The placenta connects mother and child, it is needed to nourish the baby, after birth it will no longer be there - as a rule, this is the only knowledge about the placenta at the beginning of pregnancy. As it enlarges and after undergoing an ultrasound, the expectant mother learns the following about the placenta: “the placenta is located high (or low)”, “its degree of maturity is now such and such.” Then the placenta, like the baby, is born. True, this event is no longer so significant for many mothers against the backdrop of the arrival of the long-awaited baby.

The placenta does not appear immediately. It is formed from the chorion - the embryonic membranes of the fetus. The chorion looks like many elongated outgrowths of the membrane surrounding the unborn child, which penetrate deep into the wall of the uterus. As pregnancy progresses, the outgrowths of the chorion increase in size and turn into the placenta; it is finally formed towards the end.

The new organ has the appearance of a disk, or cake (that’s how the word placenta is translated from Latin - “cake”). One side of the placenta is attached to the uterus, and the other “looks” towards the baby. It is connected to the fetus by the umbilical cord. There are two arteries and one vein running inside the umbilical cord. Arteries carry blood from the fetus to the placenta, and veins carry nutrients and oxygen from the placenta to the baby. The umbilical cord grows with the child and by the end of pregnancy its length is on average 50-55 cm.

Place and dimensions

During pregnancy, as the baby grows, the placenta grows along with it. In addition, its location in the uterus also changes. K, when the placenta reaches full functional maturity, its diameter is 15-20 cm, and its thickness is 2.5-4.5 cm. After this period of pregnancy, the growth of the placenta stops, and then its thickness either decreases or remains the same.

During a normal pregnancy, the placenta is usually located in the area of ​​the fundus or body of the uterus, along the back wall, with a transition to the side walls - that is, in those places where the walls of the uterus are best supplied with blood. The placenta is located less frequently on the anterior wall, as it is constantly growing. The location of the placenta does not affect the development of the child.

There is a condition called placenta previa, when it is located in the lower parts of the uterus along any wall, partially or completely blocking the area of ​​the internal os. If the placenta only partially covers the area of ​​the internal os, then this is an incomplete presentation. If the placenta completely covers the area of ​​the internal os, then this is complete. In such cases, doctors are afraid of bleeding during childbirth, so they especially carefully monitor the course of pregnancy and childbirth. An even low location of the placenta occurs, when its edge is lower than it should be normally, but does not overlap the area of ​​the internal os.

The placenta is capable of moving (migrating); there is even such a term as “placenta migration.” The movement occurs due to the fact that the lower segment of the uterus changes its structure during pregnancy, and the placenta grows towards the better blood-supplied areas of the uterus (towards the fundus of the uterus). Typically, “placenta migration” occurs over 6-10 weeks and is completed by. Therefore, in I, the diagnosis of “low placenta” should not frighten. Simultaneously with the enlargement of the uterus, the placenta rises.

III degree of maturity can be determined starting from .

If the degree of maturity changes prematurely, this may indicate premature maturation of the placenta. It may occur due to a disturbance in the blood flow in the placenta (for example, as a result of late - anemia), or maybe individual feature body of a pregnant woman. Therefore, you should not be upset if an ultrasound suddenly reveals premature ripening placenta. The main thing is to look at the child’s development: if his condition does not suffer, then most likely everything is normal with the placenta.

Birth of the placenta

After the baby is born, the 3rd stage of labor begins - the afterbirth period. The placenta, membranes and umbilical cord together form the afterbirth, which is expelled from the uterus 5-30 minutes after the baby is born.

First, the afterbirth contractions begin: contractions, including the placenta attachment site, which is called the placental platform. The placenta itself cannot contract, so it moves away from the place of attachment. With each contraction, the placental area becomes smaller, and finally the placenta separates from the wall of the uterus. The doctor examines the woman in labor and, making sure that the placenta has separated from the uterus, gives permission to push.

The birth of the placenta is usually painless. After this, the doctor must examine the placenta and determine whether there is any damage to the surface of the placenta and whether all its parts have completely left the uterus. This examination is necessary to ensure that there are no parts of the placenta left in the uterus. If the integrity of the placenta is compromised, then a manual examination of the uterus is performed under anesthesia to remove any remaining placental tissue.

Based on the state of the “born” placenta, one can judge the course of pregnancy (whether there were any infectious processes, etc.). Pediatricians will need this information to know what characteristics the baby may have. And, accordingly, to prevent possible problems as quickly as possible.

Sometimes the placenta is designed in such a way that even if part of it remains in the uterus, this is not visible upon examination - there are no defects on the placenta, the edges are even. A few days after childbirth (usually this happens in the first 7 days), abdominal pain appears and bleeding increases. Then we can assume that part of the placenta still remains in the uterus. In such a situation, you should immediately consult a doctor and go to the hospital, where they will perform curettage of the uterus.

In cultures different nations There has always been respect for the placenta. This was explained by the fact that the placenta, in modern terms, is the carrier of the same genetic information as the mother and baby. Therefore, earlier, when maternity hospitals did not yet exist, the placenta was not thrown away, but was usually buried in the ground. Today in maternity hospitals it is disposed of as biological waste. But if the woman wishes, she can always pick her up from the maternity hospital.