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Placental tissue. Placenta in pregnant women. Trophic and excretory

It connects two organisms - mother and fetus, providing it with the necessary nutrients.

Where is the placenta located and what does it look like?

With a normal pregnancy, the placenta is located in the body of the uterus along its back (more often) or front wall. It is fully formed by the 15th to 16th week of pregnancy, after the 20th week, an active exchange begins through the placental vessels. From 22 to 36 weeks of gestation, the mass of the placenta increases, and by 36 weeks it reaches full functional maturity.

By outward appearance The placenta looks like a round, flat disc. By the time of childbirth, the mass of the placenta is 500-600 g, the diameter is 15-18 cm and the thickness is 2-3 cm. Two surfaces are distinguished in the placenta: the maternal one, adjacent to the wall of the uterus, and the opposite - the fetal one.

Placenta functions

  • First, gas exchange occurs through the placenta: oxygen penetrates from the maternal blood to the fetus, and carbon dioxide is transported in the opposite direction.
  • Secondly, the fetus receives through the placenta nutrients necessary for its growth and development. It must be remembered that many substances (alcohol, nicotine, narcotic drugs, many medications, viruses) easily penetrate through it and can have a damaging effect on the fetus. In addition, with its help, the fetus gets rid of the products of its vital activity.
  • Thirdly, the placenta provides immunological protection of the fetus, detaining the cells of the mother's immune system, which, having penetrated into the fetus and recognizing a foreign object in it, could trigger reactions of its rejection. At the same time, the placenta passes maternal antibodies that protect the fetus from infections.
  • Fourth, the placenta plays the role of a gland internal secretion and synthesizes hormones ( chorionic gonadotropin human (hCG), placental lactogen, prolactin, etc.), necessary to maintain pregnancy, growth and development of the fetus.

Normally, the placenta, together with the membranes (afterbirth), is born 10-15 minutes after the birth of the fetus. She is carefully examined and sent for morphological examination. Firstly, it is very important to make sure that the placenta was born as a whole (that is, there is no damage on its surface and there is no reason to believe that pieces of the placenta remained in the uterine cavity). Secondly, according to the state of the placenta, one can judge the course of pregnancy (whether there was a detachment, infectious processes, etc.).

What do doctors want to know about the placenta?

During pregnancy, it is important to identify signs of impaired placental function - placental insufficiency. To do this, during an ultrasound examination, the structure of the placenta, its location in the uterine cavity, thickness, and the size of the fetus correspond to the gestational age are studied. In addition, the blood flow in the placental vessels is studied.

Degree of maturity

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

There are four degrees of maturity of the placenta:

  • Normally, up to 30 weeks of pregnancy, the zero degree of maturity of the placenta should be determined.
  • The first degree is considered acceptable from 27 to 34 weeks.
  • The second is from 34 to 39.
  • Starting at 37 weeks, 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, the appearance of areas of salt deposition.

Place of attachment

Determined by ultrasound. As mentioned above, for normal pregnancy The placenta is located in the body of the uterus. Sometimes an ultrasound examination in the first half of pregnancy reveals that the placenta is located in the lower parts of the uterus, reaching or even overlapping the area of ​​the internal os of the cervix. In the future, as pregnancy progresses, the placenta most often shifts from the lower parts of the uterus to the top. However, if after 32 weeks the placenta still covers the area of ​​the internal os, this condition is called * placenta previa **, which is a serious complication of pregnancy.

Placenta previa can lead to the development of bleeding, which can occur in the II-III trimester of pregnancy or during childbirth.

Thickness

It is also determined by ultrasound examination - placentometry: after establishing the place of attachment of the placenta, a site is found where it has largest size, which is determined. The thickness of the placenta, as already mentioned, increases continuously up to 36-37 weeks of pregnancy (by this time it is from 20 to 40 mm). Then its growth stops, and in the future, the thickness of the placenta either decreases or remains at the same level.

A deviation from the norm of at least one of these indicators may indicate a problem during pregnancy.

Placenta(lat. placenta, "flat cake") - an embryonic organ in all females of placental mammals, which allows the transfer of material between the circulatory systems of the fetus and the mother; In mammals, the placenta is formed from the embryonic membranes of the fetus (villous, chorion, and urinary sac - allantois), which adhere tightly to the wall of the uterus, form outgrowths (villi) protruding into the mucous membrane, and thus establish close connection between the embryo and the maternal organism, which serves for nutrition and respiration of the embryo. The umbilical cord connects the embryo to the placenta. The placenta, together with the membranes of the fetus (the so-called afterbirth) in humans, leaves the genital tract in 5-30 minutes (depending on the tactics of labor management) after the birth of the child.

Placentation

The placenta is formed most often in the mucous membrane of the posterior wall of the uterus from the endometrium and cytotrophoblast. Placenta layers (from uterus to fetus - histologically):

  1. Decidua - transformed endometrium (with decidual cells rich in glycogen),
  2. Fibrinoid (Lanthans layer),
  3. Trophoblast, covering the lacunae and growing into the walls of the spiral arteries, preventing their contraction,
  4. Blood-filled gaps
  5. Syncytiotrophoblast (syncytiotrophoblast),
  6. Cytotrophoblast (individual cells that form syncytium and secrete biologically active substances),
  7. Stroma (connective tissue containing blood vessels, Kaschenko-Hofbauer cells - macrophages),
  8. Amnion (on the placenta synthesizes more amniotic fluid, extraplacental - adsorbs).

Between the fetal and maternal part of the placenta - the basal decidua - there are recesses filled with maternal blood. This part of the placenta is divided by decidual sects into 15-20 cup-shaped spaces (cotyledons). Each cotyledon contains a main branch, consisting of the umbilical blood vessels of the fetus, which branches further into the set of chorionic villi that form the surface of the cotyledon (denoted as Villus in the figure). Due to the placental barrier, the blood flow of the mother and the fetus does not communicate with each other. The exchange of materials takes place using diffusion, osmosis or active transport. From the 4th week of pregnancy, when the baby's heart begins to beat, the fetus is supplied with oxygen and nutrients through the "placenta". Until 12 weeks of pregnancy, this formation does not have a clear structure, up to 6 weeks. - is located around everything fetal egg and is called chorion, "placentation" takes place at 10-12 weeks.

Where is the placenta located and what does it look like?

With a normal pregnancy, the placenta is located in the region of the body of the uterus, developing most often in the mucous membrane of its posterior wall. The location of the placenta does not significantly affect the development of the fetus. The structure of the placenta is finally formed by the end of the first trimester, but its structure changes as the needs of the growing baby change. From 22 to 36 weeks of gestation, an increase in the mass of the placenta occurs, and by 36 weeks it reaches full functional maturity. Normal placenta by the end of pregnancy, it has a diameter of 15-18 cm and a thickness of 2 to 4 cm.

Placenta functions

  • Gas exchange function of the placenta Oxygen from the mother's blood enters the fetal blood according to simple diffusion laws; carbon dioxide is transported in the opposite direction.
  • Nutrient supply Through the placenta, the fetus receives nutrients, metabolic products come back, what is excretory function placenta.
  • Hormonal function of the placenta The placenta plays the role of an endocrine gland: chorionic gonadotropin is formed in it, which maintains the functional activity of the placenta and stimulates the production of large amounts of progesterone by the corpus luteum; placental lactogen playing important role in the maturation and development of the mammary glands during pregnancy and in their preparation for lactation; prolactin, which is responsible for lactation; progesterone, which stimulates the growth of the endometrium and prevents the release of new eggs; estrogens that cause endometrial hypertrophy. In addition, the placenta is capable of secreting testosterone, serotonin, relaxin, and other hormones.
  • Protective function of the placenta The placenta has immune properties - it passes the mother's antibodies to the fetus, thereby providing immunological protection. Some of the antibodies pass through the placenta, protecting the fetus. The placenta plays a role in the regulation and development of the immune system of the mother and the fetus. At the same time, it prevents the emergence of an immune conflict between the organisms of the mother and the child - the immune cells of the mother, recognizing a foreign object, could cause rejection of the fetus. However, the placenta does not protect the fetus from certain drugs, drugs, alcohol, nicotine, and viruses.

Human placenta

Human placenta - placenta discoidalis, placenta of the hemochorial type: maternal blood circulates around the thin villi containing fruit capillaries. In the domestic industry since the 30s, prof. V.P. Filatov and the placenta extract and placenta suspension are produced. Placenta drugs are actively used in pharmacology. Stem cells are sometimes obtained from umbilical cord blood and are stored in hemabanks. Stem cells could theoretically be later used by their owner for treatment. serious diseases such as diabetes, stroke, autism, neurological and hematological diseases. In some countries, the placenta is offered to be taken home in order, for example, to make homeopathic medicines or to bury it under a tree - this custom is widespread in the most different regions the world. In addition, nutritious meals can be made from the placenta, which is a valuable source of protein, vitamins and minerals.

What do doctors want to know about the placenta?

There are four degrees of maturity of the placenta. Normally, up to 30 weeks of pregnancy, the zero degree of maturity of the placenta should be determined. The first degree is considered acceptable from 27 to 34 weeks. The second - from 34 to 39. Starting from 37 weeks, 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, the appearance of areas of salt deposition. Placenta attachment site. Determined by ultrasound (for the location of the placenta in uncomplicated pregnancy, see above). The thickness of the placenta, as already mentioned, continuously grows up to 36-37 weeks of pregnancy (by this time it is from 20 to 40 mm). Then its growth stops, and in the future, the thickness of the placenta either decreases or remains at the same level. Why is it important for doctors to know all these parameters characterizing the location and condition of the placenta? The answer is simple: because a deviation from the norm of at least one of them may indicate a dysfunctional development of the embryo.

Placenta problems

Low attachment of the placenta... Low attachment of the placenta is a fairly common pathology: 15-20%. If low location The placenta is determined after 28 weeks of pregnancy, they speak of placenta previa, since in this case the placenta at least partially overlaps the uterine pharynx. However, fortunately, only 5% of the placenta remains in low position until 32 weeks, and only a third of these 5% of the placenta remains in this position by 37 weeks.

Placenta previa... If the placenta reaches the internal pharynx or overlaps it, they speak of placenta previa (that is, the placenta is located in front of the presenting part of the fetus). Placenta previa is most often found in re-pregnant women, especially after previous abortions and postpartum diseases. In addition, tumors and anomalies in the development of the uterus, low implantation of the ovum contribute to placenta previa. Ultrasound determination of placenta previa in early dates pregnancy may not be confirmed at a later date. However, such an arrangement of the placenta can provoke bleeding and even premature birth, and therefore is considered one of the most serious types of obstetric pathology.

Placenta accreta... Chorionic villi, during the formation of the placenta, are "embedded" into the lining of the uterus (endometrium). This is the same membrane that is rejected during menstrual bleeding - without any damage to the uterus and to the body as a whole. However, there are times when the villi grow into the muscle layer, and sometimes into the entire thickness of the uterine wall. The addition of the placenta is also facilitated by its low location, because in the lower segment of the uterus the chorionic villi "deepen" into the muscle layer much more easily than in the upper sections.

Tight attachment of the placenta... In fact, the dense attachment of the placenta differs from the increment in the shallower depth of germination of the chorionic villi into the wall of the uterus. In the same way as placenta accreta, tight attachment often accompanies presentation or low placenta. To recognize the increment and dense attachment of the placenta (and to distinguish them from each other), unfortunately, is only possible during childbirth. With dense attachment and accretion of the placenta in the subsequent period, the placenta does not spontaneously separate. With tight attachment of the placenta, bleeding develops (due to detachment of the placenta); when the placenta is accreted, there is no bleeding. As a result of accretion or tight attachment, the placenta cannot separate in the third stage of labor. In the case of a tight attachment, they resort to manual separation of the placenta - the doctor taking delivery, inserts his hand into the uterine cavity and separates the placenta.

Placental abruption... As noted above, placental abruption can accompany the first stage of labor when the placenta is low or occur during pregnancy with placenta previa. In addition, there are cases when a premature detachment of a normally located placenta occurs. It's heavy obstetric pathology observed in 1-3 out of a thousand pregnant women. Manifestations of placental abruption depend on the area of ​​the detachment, the presence, size and rate of bleeding, the reaction of the woman's body to blood loss. Small detachments may not manifest themselves in any way and may be detected after childbirth when examining the placenta. If placental abruption is insignificant, its symptoms are mild, with a whole fetal bladder in childbirth, it is opened, which slows down or stops placental abruption. Expressed clinical picture and growing symptoms internal bleeding- indications for a cesarean section (in rare cases, you even have to resort to removing the uterus - if it is soaked in blood and does not respond to attempts to stimulate its contraction). If, with placental abruption, childbirth occurs through the natural birth canal, then manual examination of the uterus is mandatory.

Early maturation of the placenta... Depending on the pathology of pregnancy, the failure of the placenta function during its excessively early maturation is manifested by a decrease or increase in the thickness of the placenta. So a "thin" placenta (less than 20 mm in the third trimester of pregnancy) is typical for late toxicosis, threats of abortion, fetal malnutrition, while in hemolytic disease and diabetes mellitus, a "thick" placenta (50 mm or more) indicates placental insufficiency. Thinning or thickening of the placenta indicates the need for therapeutic measures and requires repeated ultrasound examination.

Late maturation of the placenta... It is rarely observed, more often in pregnant women with diabetes mellitus, Rh-conflict, as well as in birth defects fetal development. The delay in maturation of the placenta leads to the fact that the placenta, again, inadequately performs its functions. Often late maturation of the placenta leads to stillbirth and mental retardation at the fetus. Reducing the size of the placenta. There are two groups of reasons leading to a decrease in the size of the placenta. Firstly, it can be a consequence of genetic disorders, which is often combined with fetal malformations (for example, Down's syndrome). Secondly, the placenta may "fall short" in size due to the influence of various unfavorable factors (severe gestosis in the second half of pregnancy, arterial hypertension, atherosclerosis), which ultimately lead to a decrease in blood flow in the vessels of the placenta and to its premature maturation and aging. In either case, the "small" placenta does not cope with the responsibilities assigned to it of supplying the baby with oxygen and nutrients and getting rid of metabolic products.

An increase in the size of the placenta... Placental hyperplasia occurs in Rh-conflict, severe anemia in a pregnant woman, diabetes mellitus in a pregnant woman, syphilis and other infectious lesions of the placenta during pregnancy (for example, with toxoplasmosis), etc. It makes little sense to list all the reasons for the increase in the size of the placenta, but it must be borne in mind that when this condition is detected, it is very important to establish the cause, since it is it that determines the treatment. Therefore, one should not neglect the studies prescribed by the doctor - after all, the consequence of placental hyperplasia is the same placental insufficiency, leading to a delay intrauterine development fetus.

Which doctors should I go to for examination of the Placenta?

What diseases are associated with the Placenta:

What tests and diagnostics need to be done for the Placenta:

Echographic fetometry

Placentography

Doppler ultrasonography of MPK and FPK

Cardiotocography

Cardiointervalography

Placenta, or baby place, is an amazing organ female body, existing only during pregnancy. It plays an invaluable role in the development of the fetus, ensuring its growth, development, nutrition, respiration and excretion of processed metabolic products, as well as protecting the fetus from all kinds of harmful effects... Inside this organ, which outwardly somewhat resembles a cake, is a unique membrane - "customs and border guard" between the two circulatory systems mother and fetus.

Placental development

Already on the 7th day after fertilization, implantation begins - the introduction of the fetus into the wall of the uterus. In this case, special enzymes are released that destroy the area of ​​the mucous membrane of the uterus, and part of the outer cells of the ovum begins to form villi. These villi are turned into cavities - lacunas that arise at the site of the collapse of the vessels of the inner layer of the uterus. The lacunae are filled with maternal blood, from where the fetus will receive all the nutrients. This is how extraembryonic organs begin to form (chorion, amnion, yolk sac), the intensive formation of which is called placentation and lasts 3-6 weeks. And, although the tissues and organs of the unborn baby are not formed from them, further development the embryo is impossible without them. Chorion after a while will turn into a placenta, and the amnion will become fetal bladder... By 12 weeks, the placenta already resembles a round cake in shape or a disc thinned along the edge, and by the 16th week, the formation of the placenta is already completely completed. As the gestation period increases, the mass of the placenta increases, the density of the placenta tissues changes. This so-called “ripening” is a natural process that allows timely and fully meet the constantly changing needs of the fetus. The degree of maturity is determined by ultrasound examination (ultrasound). An ultrasound scan verifies the data regarding the thickness of the placenta and the accumulation of calcium salts with the period of bearing the baby. Doctors differentiate four stages of placental maturity, including zero, which is often found at 30 weeks. This is followed by the first stage, appearing from 27 to 36 weeks, from 34 to 39, the second and last, later than 36 weeks of pregnancy.

Placental developmental disorders

The nature and rate of maturation of the placenta are genetically programmed and may vary slightly in the norm.
Ultrasound diagnosis premature aging the placenta is exposed if the 2nd degree of maturity appeared before 32 weeks and the 3rd degree of maturity before 36-37 weeks of pregnancy. Accelerated maturation of the placenta can be even and uneven. Uneven accelerated maturation of the placenta is often based on circulatory disorders in its individual areas. Most often this happens with long-term late toxicosis, in pregnant women with metabolic disorders.
Despite the fact that there is no convincing evidence of a connection between ultrasound diagnosis of premature aging and impaired placental function, a course of prevention of placental insufficiency is recommended for pregnant women with accelerated maturation of the placenta.

Placenta structure

The name of the organ comes from lat. placenta- pie, flatbread, pancake. The placenta has a lobular structure. These lobules are called cotyledons. Cotyledons are separated by septa - septa. Each lobule of the placenta contains many small vessels... In this organ, two systems of blood vessels converge. One of them (maternal) connects the placenta with the vessels of the uterus, the other (fruit) is covered with amnion. Vessels go along this membrane, which combine into larger ones, which ultimately form the umbilical cord. The umbilical cord is a cord-like formation that connects the fetus and the placenta. There are three vessels in the umbilical cord. Despite the apparent discrepancy, the vessel, which is called venous, carries arterial blood, and venous blood flows in two arterial vessels. These large vessels are surrounded by a special preservative.
A barrier membrane (one layer of cells) is located between the two vascular systems, due to which the blood of the mother and the fetus does not mix.

Disorders of the structure of the placenta

A change in the size (diameter and thickness) of the placenta, detected by ultrasound, does not always mean that the pregnancy is unfavorable. Most often, such "deviations" are only individual feature and does not affect the development of the fetus in any way. Only significant deviations deserve attention.

Small placenta, or placental hypoplasia... Such a diagnosis is legitimate only with a significant decrease in the size of the placenta. The cause of this condition is most often genetic abnormalities, while the fetus often lags behind in development and has other malformations.

Thin placenta considered a child's place with underweight at generally normal sizes. Sometimes a thin placenta accompanies placental insufficiency and therefore is a risk factor for intrauterine growth retardation and serious problems in the neonatal period.

Increase in the thickness and size of the placenta can also be a consequence of the pathological course of pregnancy. The most common reasons for an increase in the size of the placenta are: swelling of its villi, due to inflammation ( placentitis or chorioamnionitis). Chorioamnionitis can be caused by the penetration of microorganisms into the placenta from the external genital organs (with STIs - chlamydia, mycoplasmosis, herpes, gonorrhea) or with blood flow (with influenza, SARS, kidney inflammation, toxoplasmosis, rubella). Placentitis is accompanied by impaired placental function (placental insufficiency) and intrauterine infection of the fetus.

In addition to inflammation, thickening of the placenta can be observed with anemia (decreased hemoglobin) and diabetes mellitus in the mother, as well as with a conflict over rhesus or blood group. It is very important to identify true reason thickening of the placenta, since each case requires its own approaches to the treatment and prevention of complications in the fetus.

Changes in the lobular structure of the placenta
Such anomalies include two-lobed, three-lobed placentas, as well as cases when a child's place has additional lobule, standing as if "apart".
During childbirth, the additional lobule can break off from the main one and serve as a source of bleeding in postpartum period... That is why obstetricians always examine the placenta in detail after birth.

As with any other organ, tumors are sometimes found in the placenta. The most common tumor is chorioangioma- pathological proliferation of blood vessels in any part of the placenta. Choriangioma refers to benign tumors, never metastases to other organs.

Placenta location in norm and pathology

Usually the placenta is located closer to the bottom of the uterus along one of the walls of the uterus. However, in some women in the early stages of pregnancy, the placenta forms closer to the lower part of the uterus, often reaching the internal uterine pharynx... In this case, they talk about the low location of the placenta. With ultrasound examination low-lying consider the placenta, the lower edge of which is located at a distance of no more than 6 cm from the internal os of the cervix. Moreover, in the fifth month of pregnancy, the frequency of detecting a low location of the placenta is about 10 times higher than before childbirth, which is explained by the "migration" of the placenta. The tissues of the lower part of the uterus stretch upward with increasing gestational age, as a result of this, the lower edge of the placenta also shifts and takes correct position... Ultrasound in dynamics allows you to get an idea of ​​placental migration with a high degree of accuracy.

Placenta previa- a much more serious diagnosis, with the placenta completely or partially blocking the inner opening of the cervical canal. The tissue of the placenta does not have great extensibility, it does not have time to adapt to the rapidly expanding wall of the lower segment of the uterus, as a result, at some point its detachment occurs, which is accompanied by bleeding. Such bleeding begins suddenly, it is painless, it recurs with the growth of pregnancy, and it is impossible to guess when and what the next bleeding will be in terms of strength and duration. Bleeding with placenta previa threatens the life of both the woman and the child. Even if the bleeding has stopped, the pregnant woman remains under the supervision of the hospital doctors until the due date.

Placenta functions

Already from the moment the placenta was laid "tirelessly" works for the good of the baby. The placental barrier is impervious to many harmful substances, viruses, bacteria. At the same time, oxygen and substances necessary for life easily pass from the mother's blood to the child, as well as waste products from the fetus's body easily enter the mother's blood, after which they are excreted through her kidneys. The placental barrier performs immune function: passes protective proteins (antibodies) of the mother to the child, ensuring his protection, and at the same time detains the cells of the mother's immune system, which can cause a reaction of rejection of the fetus, recognizing a foreign object in it. In addition, the placenta produces hormones that are important for a successful pregnancy, and enzymes that destroy harmful substances.

The hormones secreted by the placenta include chorionic gonadotropin (hCG), progesterone, estrogens, placental lactogen, somatomammotropin, mineralocorticoids. To assess the hormonal function of the placenta, a test is used to determine the level of estriol in the urine and blood of a pregnant woman. If the placenta does not work well, then the level of this hormone decreases.

Placental dysfunction

With an unfavorable pregnancy, the function of the placenta may be impaired. There is a so-called placental insufficiency, in which the uteroplacental and fetal-placental blood flow decreases, gas exchange and metabolism in the placenta are limited, and the synthesis of its hormones decreases. According to medical statistics, placental insufficiency develops in about 24% of pregnant women. Distinguish between primary and secondary placental insufficiency.

Primary (early) placental insufficiency develops up to 16 weeks of pregnancy, occurs during the formation of the placenta. Its causes are more often the pathology of the uterus: endometriosis, uterine fibroids, malformations of the uterus (saddle, small, two-horned), previous abortions and hormonal and genetic disorders... In some cases, primary placental insufficiency becomes secondary.

Secondary (late) placental insufficiency, as a rule, occurs against the background of an already formed placenta, after 16 weeks of pregnancy. In the occurrence of late placental insufficiency great importance have infections, late toxicosis, the threat of termination of pregnancy, as well as various diseases mothers (arterial hypertension, adrenal cortex dysfunction, diabetes, thyrotoxicosis, etc.).

Symptoms of fetal hypoxia indicate a change in the respiratory function of the placenta. Chronic hypoxia fetus and a violation of the nutritional function of the placenta leads to a delay in its intrauterine development. The fetus, which develops in conditions of placental insufficiency, is much more susceptible to the risk of trauma during childbirth and morbidity during the neonatal period.

At present, unfortunately, it is not possible to completely cure the placental insufficiency that has arisen. Therefore, it is very important to carry out prevention in women who have risk factors for the development of placental insufficiency. Everything therapeutic measures with placental insufficiency, they are aimed at maintaining the existing function of the placenta and, if possible, prolong the pregnancy until the optimal time of delivery. If the indicators deteriorate during treatment, emergency delivery is performed by caesarean section, regardless of the gestational age.

Diagnostics of the state of the placenta

During pregnancy, the state of the placenta and its function is a subject close observation doctor. After all, it is on this organ that the success of pregnancy and the health of the unborn baby depend.

The position, development and structural features of the placenta allow us to evaluate ultrasound (ultrasound). At the same time, the localization and thickness of the placenta, the degree of maturity of the placenta to the gestational age, the volume of amniotic fluid, the structure of the umbilical cord, and possible pathological inclusions in the structure of the placenta are determined. In addition, the anatomical structure of the fetus is studied to identify abnormalities in its development, respiratory and motor activity of the fetus.

To diagnose the function of the placenta, in addition to ultrasound, are used:

A) laboratory methods - based on determining the level of placental hormones (estriol, chorionic gonadotropin, placental lactogen), as well as the activity of enzymes (oxytocinase and thermostable alkaline phosphatase) in the blood of pregnant women.

B) fetal cardiac assessment... In addition to simple listening with an obstetric stethoscope, the most accessible and common method for assessing fetal cardiac activity is cardiotachography, which is based on recording changes in the fetal heart rate depending on uterine contractions, the action of external stimuli or the activity of the fetus itself.

V) dopplerometry- This is a variant of an ultrasound study, in which the velocity of blood flow in the vessels of the uterus, umbilical cord and fetus is assessed. Allows you to directly assess the state of blood flow in each of the vessels.

Placenta in labor

During the first (period of contractions) and the second (forced) period of labor, the placenta remains the most important organ of the child's life until his birth. Within half an hour after the birth of the child, the last (third) period of labor takes place, during which the placenta is normally separated and fetal membranes, making up a child's seat or afterbirth. This period is completely painless, but the woman is still in the delivery room, her condition is monitored, her blood pressure and pulse are measured. Because an overflowing bladder prevents the uterus from contracting, it is emptied using a catheter. After a while, a woman may feel weak contractions that last no more than a minute. This is one of the signs of separation of the placenta from the walls of the uterus. Not all women experience these contractions.

Therefore, obstetricians also use other signs of separation. When the placenta is separated, the bottom of the uterus rises above the navel, deviates to the right, a protrusion appears above the bosom. When pressed with the edge of the hand above the bosom, the uterus rises up, and the segment of the umbilical cord hanging from the birth canal is not pulled into the vagina. If there are signs of separation of the placenta, the woman is asked to push, and the afterbirth is born without any difficulties.

The placenta is a spongy organ, oval or semicircular in shape, with a normal full-term pregnancy and a fetal weight of 3300-3400 g, the diameter of the placenta is 15 to 25 centimeters, thickness is 2-4 centimeters, weight is 500 grams.

After the birth of the placenta, it is placed on the table maternal side upward and examine the integrity of the placenta and membrane. There are two surfaces of the placenta: the fruit, facing the fetus, and the mother, adjacent to the wall of the uterus. The fruit surface is covered with amnion - a smooth, shiny grayish shell; the Umbilical cord is attached to its central part, from which the vessels radiate radially. The maternal surface of the placenta is dark brown, divided into several (10-15) lobules.

After the birth of the placenta, the uterus becomes dense, rounded, located in the middle, its bottom is located between the navel and the bosom.

Disorders of the placenta

If within 30-60 minutes there are no signs of separation of the placenta, then they try to isolate it with special techniques of massage of the uterus. If this does not happen, talk about tight attachment or partial accretion of the placenta... In this case, under general anesthesia the doctor enters the uterine cavity with his hand and tries to manually separate the placenta from the walls. If this fails, then they talk about complete (true) placental accretion, transport the woman to the operating room and perform an immediate surgery... With a true increment of the placenta, in the overwhelming majority of cases, there is only one way out - surgical removal uterus.

To recognize the increment and dense attachment of the placenta (and to distinguish them from each other), unfortunately, is only possible during childbirth. With a tight attachment of the placenta, bleeding develops (due to detachment of the placenta), with placenta accreta, there is no bleeding. The reason for the violation of the separation of the placenta is the deep penetration of the chorionic villi into the thickness of the uterus, extending beyond the mucous membrane of the uterus, and sometimes into the entire thickness of the uterine wall. Dense attachment of the placenta differs from the increment in a shallower depth of germination of chorionic villi into the uterine wall.

If the afterbirth was born independently, but upon examination it was revealed placenta defects or bleeding continues, then a manual or instrumental examination of the uterine cavity is performed with the removal of the remaining piece.

Premature detachment normally located placenta... Sometimes the placenta begins to separate not in the third stage of labor, but earlier. The cause of premature detachment during labor may be excessive generic activity(at wrong positions the fetus, a discrepancy between the size of the pelvis and the fetus, or excessive drug stimulation). In very rare cases, premature placental abruption occurs before delivery, usually as a result of an injury from a fall. Placental abruption is one of the most formidable obstetric complications, it leads to significant blood loss to the mother and threatens the life of the fetus. With placental abruption, the fetus stops receiving blood from the umbilical cord, which is attached to the placenta, and the supply of oxygen and nutrients from the mother's blood to the fetus stops. Death of the fetus is possible. Placental abruption symptoms are not the same in different cases... There may be severe bleeding from the genitals, or it may not be at all. Possibly lack of fetal movement, strong constant pain v lumbar spine and abdomen, reshaping of the uterus. When diagnosing placental abruption, ultrasound is used. When the diagnosis is confirmed, immediate delivery by caesarean section is indicated.

Prevention of placental problems

The placenta is an amazingly complex system, a well-coordinated mechanism, a whole factory that performs many functions. But, unfortunately, any system, even the most perfect, sometimes fails. By virtue of the most various reasons on different dates pregnancy, there are deviations in the development and functioning of the placenta.

The leading place in prevention is timely treatment chronic diseases and giving up bad habits, which are often the cause of abnormalities in the placenta. It is also important to comply with the appropriate regime: good rest at least 10-12 hours a day (preferably sleeping on the left side), elimination of physical and emotional stress, staying on fresh air 3-4 hours a day, rational balanced diet, the maximum protection of the pregnant woman from meeting the infection. The course of prevention includes multivitamins, iron and other minerals.

Placenta I Placenta (Latin placenta flatbread; synonym)

developing in the uterine cavity during pregnancy, which makes a connection between the mother's body and the fetus. Complex biological processes occur in the placenta that provide normal development embryo and fetus, hormone synthesis, fetal protection action 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. The egg after ovulation 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 the abdominal cavity. Under the influence of enzymes secreted by the epithelium of the fallopian tube, the fertilized (unicellular) is freed from the cells of the radiant crown. During the passage through the fallopian tube (3-4 days), the fertilized egg divides into blastomeres, and a multicellular embryo enters the uterus (). Blastomeres of the outer layer form morula, and those located inside -. From the first P. with amnion and chorion develops (see. Fetal membranes), from the second - the Fruit. A small cavity filled with fluid forms between the trophoblast and the embryoblast: the embryo at this stage of development is called a blastocyst. at the end of the 1st - the beginning of the 2nd week after fertilization, it is immersed (implanted) into the thickness of the endometrium. in the endometrium, after immersion in it, the blastocyst is closed by the proliferating epithelium. By 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 of vessels and glands that secrete, rich in acidic mucoids, glycoproteins and glycogen, and compact (superficial) with a small number of glands and a large number large connective tissue cells containing.

After implantation, the functional layer of the endometrium thickens, its glands are filled with secretion even more, the connective tissue cells of the compact zone increase, the amount of glycogen, lipids, vitamin C, nonspecific esterases, acidic 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 decidual (falling off) shell. Several parts are distinguished in the decidua: the basal one, located between the ovum and the uterine wall; capsular, covering the fetal from the side of the uterine cavity; parietal, lining the entire inner surface uterus, with the exception of the area of ​​attachment of the ovum (see. rice. 2 to the article Pregnancy).

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

By the 12-13th day of development of the embryo, it grows into the primary villi located on the surface of the chorion facing the myometrium - secondary villi of the trophoblast are formed. At the 3rd week of development of the embryo, vessels (fruit) begin to grow into the stroma of the secondary villi - tertiary villi are formed; this process is called placentation. the tertiary nap has two layers. Its outer layer is formed by syncytium, the inner layer is formed by cytotrophoblast (Langhans cells) located on the basement membrane separating the trophoblast from the stroma of the villi. is a continuous acellular layer of cytoplasm with oval or rounded 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, rounded, closely adjacent cells. In II and especially in III trimesters of pregnancy, the cytotrophoblast is represented by single, larger cells than in the first trimester of pregnancy. Syncytium and cytotrophoblast are chorionic epithelium of villi. 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 with the amnion covering it forms the fetal part of 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 rest, smaller, villi are freely located in the intervillous space (terminal villi) and are resorptive in their function. By the end of pregnancy, the number of terminal villi and fruiting capillaries in their stroma increases significantly, the chorial becomes thinner - single Langhans cells remain under the syncytium. In this case, it directly adjoins the basement membrane, and the fetal capillaries approach it and the syncytium (syncytiocapillary membrane). The basal part of the decidua with partitions extending from it forms mother part placenta.

From the moment of the 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 gestation. By this period, the tertiary villi and the final formation of the placenta are completed.

Mature placenta ( rice. 1 ) in shape resembles a round cake or a disc thinned along the edge. It is usually located on the back or front wall of the uterus, sometimes partially extends onto the side walls or the fundus of the uterus. In the early stages of pregnancy P. often reaches the internal uterine pharynx, but in most women subsequently, with the growth of the uterus, it rises. 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 surfaces of P.: fruit, facing the fetus, and maternal, adjacent to the wall of the uterus. P.'s fruit surface is covered with amnion - a smooth shiny grayish cover; the Umbilical cord is attached to its central part, from which the vessels radiate radially. The maternal surface of P. is dark brown, divided into 15-20 lobules - cotyledons.

Cotyledons are separated from each other by P. septa. Each cotyledon is autonomous from the vessels of the fetus; it contains two or more stem villi and their numerous branches. From the umbilical arteries, the deoxygenated fetus enters the villous vessels (fetal capillaries), from the fetal blood it passes into the maternal blood, which enters the intervillous space from the endometrial arteries (spiral arteries of the spongy zone of the decidual membrane), and from the maternal blood passes into the fetal capillaries. Oxygenated fetal blood from cotyledons is collected to the center of P. and then enters the umbilical vein. Deoxygenated maternal blood flows from the intervillous space into the veins of the endometrium, which are scattered over the entire surface of the basal decidua. The scheme of circulation of fetal and maternal blood in the placenta is presented in rice. 2 ... Maternal and fetal blood do not mix, there is between them, consisting of the endothelium of the fruit capillaries, the stroma and the chorionic epithelium of the tertiary villi.

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

In addition, P. performs a protective function. Basically, in the syncytium and in the cells of the stroma of the villi, with the help of enzymes, the destruction of exogenous and endogenous (formed both in the mother's body and in the body of the fetus) harmful substances occurs. Decomposition products are thrown into the intervillous space. P.'s barrier function depends on its permeability. The degree and rate of transition of substances through P. are determined by various factors, incl. the area and thickness of the syncytiocapillary membranes, devoid of microvilli, the intensity of the uteroplacental blood flow. P. increases up to 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 P.'s aging. incl. and for harmful substances than during physiological pregnancy. In this case, the risk of antenatal fetal pathology increases sharply, and the outcome of pregnancy and childbirth, the condition of the fetus and the newborn depend on the degree and duration of the damaging factor and on the nature of the compensatory-adaptive reactions of the fetoplacental system.

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

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

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

Glucocorticoid hormones quickly bind to blood proteins of a pregnant woman and, having passed through P., are actively destroyed in the liver of the fetus, and therefore do not pose a danger to him. Preparations of sex hormones easily pass through P., 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 of 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 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 genital organs in female fetuses: an increase in the clitoris, fusion of labioscrotal folds. , having a high molecular weight, does not penetrate through P..

Direct-acting anticoagulants () do not pass through P. and do not affect the clotting system of the fetus, while indirect-acting, penetrating through P., cause hypocoagulation in the fetus, which prevents their use during pregnancy. Of the narcotic drugs, only sombrevin is rapidly 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 (morphine, fentanyl, etc.), penetrating through P., suppress the respiratory fetus to a varying degree.

Depolarizing muscle relaxants (ditilin) ​​poorly dissolve in lipids and have a high degree of ionization, as a result of which their passage through P. is difficult. Unlike them, non-depolarizing muscle relaxants (tubocurarine chloride, diplacin) pass through P. more easily and can cause relaxation of skeletal muscles and at the fetus. used for the treatment of epilepsy (diphenin, trimethine, hexamidine, etc.), pass through P. and cause a violation of the development of the central nervous system, skull and face of the fetus, and therefore it is not recommended to prescribe them in the first trimester of pregnancy.

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

To determine the signs of separation of the placenta in the III stage of labor, use special techniques (see. Childbirth). After the release of the placenta from the uterine cavity, P. is carefully examined, measured, weighed, if necessary, carry out its histological examination.

Pathology. P.'s hypoplasia is considered to be a decrease in its size in comparison with normal for a given weight of the fetus. With an average weight of a full-term fetus, P.'s hypoplasia is said if its weight is less than 400 G, and the diameter is less than 16 cm... The reasons for P.'s hypoplasia are violation of implantation in case of inferiority of the endometrium; embryotoxic factors (some drugs, chemical poisons, etc.), acting in the first trimester of pregnancy; vascular disorders (late toxicosis of pregnant women, hypertonic disease). P. with her hypoplasia is reduced, which leads to fetal malnutrition. With significant P.'s hypofunction, fetal death may occur.

Hyperplastic at full-term pregnancy and the average weight of the fetus is considered P. weighing more than 700 G and with a diameter of more than 20 cm(with a large fetus, such an increase in P. cannot be considered as hyperplasia). P. can be increased with hemolytic disease of the fetus (in this case P. is edematous, but its villi are underdeveloped), inferiority of the endometrium after abortion (P. increases compensatory), venous stasis.

Possible anomalies in P. cm lining most of the uterine cavity. Belt P. is a strip 20-23 long cm and a width of 4-6 cm... With filmy and waist P. development of the fetus can be disturbed. Two- and three-lobed P., the placenta with additional lobules, as a rule, do not lead to a violation of the fetus. The accessory can stay in the uterus and lead to uterine bleeding in the postpartum period.

With a complicated course of pregnancy (gestosis, etc.), extragenital diseases of the mother in P., dystrophic and compensatory changes occur. Dystrophic changes in placental tissue are preceded by hemodynamic disturbances: hemorrhages in the intervillous space ( rice. 3, a ), plethora of vessels of the stroma of the stem villi ( rice. 3, b ), etc. Then, dystrophic changes are detected with the formation of pseudoinfarctions (dystrophic altered villi surrounded by a fibrinoid), sclerosing 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 ), syncytium of terminal villi with the formation of syncytial nodules ( rice. 5, in ), an increase in the number of small end villi.

In the edematous form of hemolytic disease of the fetus, P. is edematous, with hemorrhages (Fig. 6), often foci of necrosis (Fig. 7) and calcification are 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 P. ().

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

Anomalies of development, dystrophic and inflammatory changes P. can lead to placental insufficiency. The item can be located in the area of ​​the internal uterine pharynx (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 detachment of the normally located placenta (see Premature detachment of the placenta). Choriocarcinoma is also referred to P.'s pathology (see. Trophoblastic disease).

Bibliography: Kiryushchenkov A.P. and Tarakhovsky M.L. Influence medicines on the fruit, M., 1990; V.E. Radzinsky and Smalko P.Ya. placental insufficiency, Kiev, 1987, bibliogr .; Serov V.N., Strizhakov A.N. and Markin S.A. Practical, p. 58, 233, M., 1989.

Rice. 4b). Microdrug of dystrophically altered placenta in full-term pregnancy: calcium salt deposits (indicated by arrows); staining with hematoxylin and eosin; × 65.

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

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

the umbilical cord is edematous, with hemorrhages ">

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

movements 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 villus to the basal decidua. Oxygenated blood is shown in red, deoxygenated - in purple: 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 - the circulation of fetal blood in the villi of the placenta, II - the circulation of maternal blood in the intervillous space, III - the direction of movement of the 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 villus to the basal decidua. Oxygenated blood is shown in red, deoxygenated - in purple: arrows indicate the direction of blood flow.

II Placenta (placenta, BNA, JNA, LNH; lat. "Pie", "cake";. Child's place)

an organ formed during pregnancy, developing from the membranes, mainly the chorion and the uterine membrane that has grown together with it; through P., substances are carried between the organisms of the mother and the embryo (fetus).

1. Small medical encyclopedia. - M .: Medical encyclopedia... 1991-96 2. First health care... - M .: Bolshaya Russian Encyclopedia... 1994 3. Encyclopedic Dictionary of Medical Terms. - M .: Soviet encyclopedia. - 1982-1984... Dictionary of foreign words of the Russian language

PLACENTA, organ of PLACENTAL MAMMALs, which connects the fetus to the mother's wall, providing nutrition, gas exchange and excretion of the fetus. Part of the placenta contains tiny blood vascular ramifications through which oxygen and nutrition ... Scientific and technical encyclopedic dictionary

Children's place, afterbirth Dictionary of Russian synonyms. placenta see afterbirth Dictionary of synonyms of the Russian language. Practical guide. M .: Russian language. Z.E. Aleksandrova. 2011 ... Synonym dictionary

Modern encyclopedia

- (lat.placenta from the Greek. plakus flatbread) (child's place), 1) an organ that communicates and metabolizes substances between the mother's body and the embryo during intrauterine development. It also performs hormonal and protective functions. After the birth of the fetus ... ... Big Encyclopedic Dictionary

- (Latin placenta, from the Greek placiis flat cake), 1) a child's place, an organ that communicates between the mother's body and the embryo during intrauterine development in some invertebrates, and many others. chordates, including almost all mammals. Do ... ... Biological encyclopedic dictionary

Placenta- (Latin placenta, from the Greek plakus flatbread), 1) an organ (baby's place), which carries out communication and metabolism between the mother's body and the embryo during intrauterine development. It also performs hormonal and protective functions. After… … Illustrated Encyclopedic Dictionary

PLACEENTA, placenta, wives. (lat.placenta) (anat.). The organ formed in a pregnant woman and a female mammal inside the uterus for the metabolism and nutrition of the embryo during fruiting is the same as the afterbirth, a child's place. Explanatory dictionary Ushakov ... Ushakov's Explanatory Dictionary

PLACENTA, s, wives (specialist.). The organ that carries out communication and metabolism between the body of the mother (female) and the fetus, a child's place. | adj. placental, oh, oh. Placental (noun; viviparous mammals) Ozhegov's Explanatory Dictionary. S.I. Ozhegov, N ... Ozhegov's Explanatory Dictionary

Afterbirth, a child's place. P. normally does not contain microorganisms. In case of a mother's illness, pathogens of syphilis, tuberculosis, hepatitis B, herpes, cytomegaly, AIDS, toxoplasmosis, and trypanosomiasis can penetrate to the fetus through P. With an ascending ... ... Microbiology Dictionary


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

The placenta connects the mother and the child, it is needed to feed the baby, after childbirth it will no longer be - as a rule, this is the only knowledge about the placenta at the beginning of pregnancy. As it grows and after undergoing an ultrasound scan, 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 for many mothers against the background of the appearance of the long-awaited baby is no longer so significant.

The placenta does not appear immediately. It is formed from the chorion - the embryonic membranes of the fetus. The chorion looks like a set of elongated outgrowths of the membrane surrounding the unborn child, which penetrate into the depths of the uterine wall. As pregnancy progresses, the chorionic outgrowths increase in size and turn into a placenta, which is finally formed by the end.

The new organ looks like a disk, or a flat cake (this is how - "flat cake" - the word placenta is translated from Latin). One side of the placenta is attached to the uterus, and the other "looks" towards the baby. The umbilical cord connects her with the fetus. Inside the umbilical cord are two arteries and one vein. The arteries carry blood from the fetus to the placenta, and the 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, when the baby grows, the placenta grows at the same time. In addition, its location in the uterus also changes. To, 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.

In normal pregnancy, the placenta is usually located in the region of the fundus or body of the uterus, along back wall, with the 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 on the anterior wall less often, as it is constantly growing. The location of the placenta does not affect the development of the baby.

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

The placenta is able to move (migrate), there is even such a term - "placental migration". The movement occurs due to the fact that the lower segment of the uterus during pregnancy changes its structure, and the placenta grows towards the better blood supply of the uterus (to the bottom of the uterus). Typically, "placental migration" lasts 6-10 weeks and ends by. Therefore, in I and the diagnosis "low location of the placenta" should not be scary. Simultaneously with the increase in the uterus, the placenta also rises.

What is the placenta for?

  • Gas exchange is carried out through the placenta: oxygen penetrates from the mother's blood to the child, and carbon dioxide is transported in the opposite direction.
  • The baby receives nutrients through the placenta and gets rid of its waste products.
  • The placenta is able to protect the body of the unborn child from the adverse effects of many substances that have entered the body of a pregnant woman. Unfortunately, placental barrier easily overcome drugs, alcohol, nicotine, components of many drugs and viruses.
  • Many hormones are synthesized in the placenta (chorionic gonadotropin, placental lactogen, estrogens, etc.).
  • The placenta, as an immune barrier, separates two genetically foreign organisms (mother and child) and prevents the development of an immune conflict between them.

Placenta maturity

The placenta grows and develops with the baby. With the help of ultrasound, you can determine the degree of her maturity. There are four degrees of maturity of the placenta, and each corresponds to a certain date pregnancy.

0 degree of maturity is up to.

III degree maturity can be determined starting from.

If the degree of maturity changes ahead of time, this may indicate premature maturation of the placenta. It can occur due to a violation of the blood flow in the placenta (for example, as a result of late toxicosis, anemia), and it can also be an individual feature of the body of a pregnant woman. Therefore, you should not be upset if suddenly an ultrasound scan reveals premature maturation placenta. The main thing is to look at the development of the child: if his condition does not suffer, then, most likely, everything is normal with the placenta.

Placenta delivery

After the baby is born, the third stage of labor begins - the successive one. The placenta, membranes and umbilical cord together form an afterbirth, which is expelled from the uterus 5-30 minutes after the birth of the baby.

First, the sequential contractions begin: the uterus contracts, including the placenta attachment, which is called the placental site. The placenta itself cannot contract, so it is displaced from the place of attachment. With each contraction, the placental area shrinks, and finally the placenta exfoliates from the wall of the uterus. The doctor examines the postpartum woman and, after making sure that the placenta has separated from the uterus, gives permission to push.

The birth of the placenta is usually painless. After that, the doctor necessarily examines the placenta and determines whether there are any lesions on the surface of the placenta, whether all of its parts have completely left the uterus. Such an examination is necessary in order to make sure that there are no parts of the placenta left in the uterus. If the integrity of the placenta is compromised, then, in order to remove the remnants of placental tissue, a manual examination of the uterus is performed under anesthesia.

By the state of the "born" placenta, one can judge the course of pregnancy (were there any infectious processes, etc.). Pediatricians will need this information to know what features the baby may have. And, accordingly, possible problems can be prevented as soon as possible.

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

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

Comment on the article "Placenta - during pregnancy and after childbirth: what you need to know"

Discussion

specially opened my card, 25 weeks - marginal presentation, the doctor sent him to an uzist whom she trusts, at 26 weeks I went to him, it turned out to be 5 cm higher ... in a week it rose (?), and even along the back wall
remake the ultrasound better and do not wind yourself up, no cops are needed! the fact that the baby lies across - it will still turn over, the kitty can stand (it is better to find out the exercises from a specialist)

At 20 weeks with my daughter, the placenta was 0.5 cm. We (England) do an ultrasound scan only at 35 weeks. And then the placenta rose to 7cm. As far as I remember, there are at least 5 or 6, but I can lie. I still have the placenta along the back wall both times, and in these cases it rises worse (the front wall of the uterus grows more).
So I wouldn't worry for 5-6 weeks. You can probably go to an ultrasound scan after 3 weeks and see the dynamics. If 3 cm is also dull, then mentally prepare for the COP. But in my opinion, it is really impossible to give birth to 3 cm (if they say so here, where there is a very relaxed attitude to pregnancy, then it is definitely impossible).

08/11/2016 11:05:01 AM, From yukgirl

Placenta - during pregnancy and after childbirth: what you need to know. Therefore, in the first and second trimesters of pregnancy, the diagnosis of "low location of the placenta" should not be scary. Simultaneously with the increase in the uterus, the placenta also rises.

Before pregnancy, I never had problems with veins, I always had straight and slender legs. And as soon as I got pregnant, it immediately became difficult to walk in heels, although the belly was not yet visible. Further it gets worse. My legs began to swell, filling with lead, and ache at night. At first, the gynecologist said that it was normal for future mother, because the load increases, but when I began to crawl out vascular mesh- it became clear that the matter was serious. Then I already specifically asked the doctor about how ...

Discussion

Mom was generally prescribed Actovegin along with phlebodia, she had terrible edema and the skin on the top of her feet became brownish-cyanotic. When I was treated, everything went away. And I was prescribed one phlebodia, more precisely, diosmin, but they gave it at the pharmacy. Helped without Actovegin. Of course, everything was not running well for me.

The worst thing is varicose veins of the genitals. I did not think that this happens, a terrible problem. Faced while walking with the second baby. With the first, everything was fine. Now they said that if the pills did not help me, they might not even let me go into labor due to the risk of bleeding and complications. Horror. I drink phlebodia as much as two pills, I pray that it will help.

Impact of hepatitis C on the placenta and birth healthy child is still debated. In pregnant women who suffer from hepatitis C when examining the placenta after childbirth, there was a significant thickening and icteric staining of the maternal membrane and villi of the placenta. Microscopic studies revealed signs of pathological immaturity of the placenta. In some cases, vascular deficiency, vascular sclerosis, accumulation of lymphoid elements, etc. were revealed. If we talk about morphological ...

Discussion

Unfortunately, hepatitis C certainly affects the development of the fetus, the course of pregnancy and the state of the placenta in particular. That is why we always recommend not only timely diagnosis infections in the expectant mother, but also carrying out safe treatment as directed by a competent doctor. One of the drugs allowed during pregnancy is a remedy based on human interferon - Viferon suppositories

The ultrasound examination is the most well-known among the examinations during pregnancy. Ultrasound is safe method allowing you to determine the pathology at any stage of pregnancy and, of course, to determine the pregnancy itself. The abdominal and vaginal ultrasound probe during pregnancy is done in two ways: an abdominal probe and a vaginal probe. During an ultrasound scan, an abdominal probe is examined with a full bladder through the front abdominal wall, i.e. the sensor is driven ...

About 20% of pregnant women think about how to prepare for childbirth, and about 10% think about how to prepare for conception. complete materials on pregnancy, childbirth, raising children. Basically, those couples are consciously preparing for this for whom it does not happen by itself, i.e. probably infertility. But there are questions that are related to preparation for conscious conception and are not directly related to treatment and medical diagnoses. There is an opinion that the children themselves ...

And it flew ... 4:30 They shake me by the leg, spread their hands with the word "Everything." I still don’t understand anything, because I want to sleep deadly after a sleepless night of wallpapering. Somehow I wake up. Alenka explains to me that the mucous plug is completely gone and she has contractions. In general, the fact that the cork has finally receded is a harbinger, but it may still be quiet for a few days before giving birth. And the fights may well be trial (by the way, we already sat with such trial in the country for an hour with ...

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have you ever heard of bleeding with blood loss of up to 3 liters or more?

Good story. Childbirth is rather quick, successful, although a moment with bleeding would have greatly strained me. It's good that the midwife was not taken aback.

For the second birth, I recommend not to leave the house, and to start and finish all repairs early :). Because if the first was given birth in 4 hours, then with the second, it would be good if the midwife had time to come to the attempts. Well, immediately after the birth of the child, before the placenta leaves, hemostatic collection + breast for the child / or intensive nipple massage.

placenta previa. Analyzes, studies, tests, ultrasound. Pregnancy and childbirth. Placenta - during pregnancy and after childbirth: what you need to know.

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gee ... it was so with my subordinate. Until the very last, she planned a COP, and in last moment(36-37 weeks) the placenta rose, and she had to give birth to her own horror ;-)
She is 37 years old, the second pregnancy, she gave birth perfectly.
From an ultrasound scan to Oparin, I never had any mistakes, except for a young girl who did an ultrasound scan for me already at the time of birth, when she mysteriously found the inner cervical os closed, despite the fact that I had an opening of 3-4 cm.

I would be very glad that I got up. Two weeks ago, I completely blocked the pharynx of the uterus. And I so would like to give birth myself this time. I all hope that what if it does rise.
So I'm glad for you, God forbid you can do without Caesarean :)

The most common complications associated with twin / triple pregnancy are: Premature birth. Low birth weight. Delayed intrauterine development of the fetus. Preeclampsia. Gestational diabetes... Placental abruption. Cesarean section... Premature birth. Childbirth before the 37th week of pregnancy is considered premature. Duration multiple pregnancy decreases with each additional child. On average, pregnancy with one baby lasts 39 weeks ...