What is the function of the placenta

So, the placenta is an important organ that is formed only during pregnancy. The placenta is formed from the chorion - the embryonic membranes of the fetus. At the very beginning of pregnancy, chorionic villi - outgrowths of the membrane - evenly cover the entire surface of the fetal egg, starting from the second month of pregnancy, on one side of the fetal egg, the villi begin to lengthen, increase in size and form the placenta.

Inside the villi flows the blood of the baby, and outside they are bathed in the blood of the mother. Between the blood flow of mother and baby there is only one layer of cells, which plays the role of a barrier between the body of mother and child. Thanks to this membrane, the blood of the mother and fetus does not mix. nine0013

However, in recent years it has become known that fetal blood cells still penetrate the placental barrier into the mother's bloodstream, and thanks to this, it has become possible to conduct genetic analyzes and determine chromosomal abnormalities, Rh factor and fetal sex from the blood of a pregnant woman (non-invasive prenatal test) .

In the placenta, there is a constant exchange of substances between mother and child. Oxygen and nutrients are supplied from the mother's blood to the fetus, carbon dioxide and metabolic products from the fetus back to the mother, to be removed from the body. nine0013

The placental barrier performs an immunological function, as it allows some protective antibodies - blood cells that fight infectious agents, in addition, it is impervious to certain harmful substances, viruses and bacteria. Unfortunately, the placental barrier is easily overcome by drugs, alcohol, nicotine, components of many drugs and some viruses.

An important function of the placenta is the production of hormones and biologically active substances. First of all, these are hormones that are important for successful pregnancy, for example, chorionic gonadotropin, placental lactogen, estrogens, etc.

Unfortunately, things don't always go well. Due to a variety of reasons, deviations in the development and functioning of the placenta may occur at different stages of pregnancy. These changes never go unnoticed for mom and baby, and often have dire consequences.

If the placenta ceases to perform its functions to the fullest, the so-called placental insufficiency develops. In fact, it consists in the deterioration of blood circulation in the mother-placenta-fetus system. nine0013

Types and causes of placental insufficiency

Doctors distinguish between acute and chronic placental insufficiency:

Acute placental insufficiency

This is a condition that requires urgent medical intervention. It is characterized by a rapid deterioration in placental blood flow. Acute placental insufficiency occurs mainly as a result of placental abruption or the death of certain areas of placental tissue, for example, during the formation of blood clots in the vessels. Abdominal trauma, antiphospholipid syndrome can serve as the cause of detachment. nine0013

Phospholipids are complex fats that are part of the membranes of all body cells. In some cases, the body's immune system produces a large number of antibodies to some of its own phospholipids and proteins that bind these lipids. They are called antiphospholipid antibodies and, when interacting with the cells of the body, cause cell damage and activation of the blood coagulation system, which leads to thrombosis.

Antiphospholipid syndrome is the most common cause of thrombotic complications in pregnancy, including placental abruption and acute placental insufficiency. nine0047 A severe course of gestosis, a formidable complication of the second half of pregnancy, manifested by edema, increased pressure and the appearance of protein in the urine, can also cause placental abruption.

Acute placental insufficiency develops when more than 2/3 of the placental surface is detached.

In case of acute placental insufficiency, it is necessary to perform a caesarean section as soon as possible to save the life of the baby and mother.

Chronic placental insufficiency

Chronic placental insufficiency is much more common in pregnant women. In this case, there is a violation of the formation and maturation of the placenta, the uteroplacental and fetal-placental blood flow decreases, gas exchange and metabolism in the placenta are limited, and the synthesis of placental hormones decreases. All these changes determine the insufficient supply of oxygen and nutrients to the baby, cause a delay in the growth and development of the fetus.

The most common causes of placental insufficiency are previous abortions, especially surgical abortion during the first pregnancy, smoking, while the number and strength of cigarettes smoked do not matter, since tobacco smoke, not nicotine, has a negative effect on the formation of defective placental vessels. nine0013

The risk group for the development of placental insufficiency also includes women with chronic diseases such as arterial hypertension, iron deficiency anemia, pyelonephritis, diabetes, thyroid disease.
In recent years, there has been a significant increase in placental insufficiency caused by bacteria, viruses, fungi. The reason for this can be both an acute infection suffered by the expectant mother during pregnancy, and the activation of a chronic infectious process in the body of a pregnant woman. nine0013

Of no small importance in the formation of chronic placental insufficiency is the pathology of the uterus: endometriosis, malformations of the uterus (saddle-shaped, bicornuate). Doctors also consider uterine fibroids to be a risk factor. Of course, a number of drugs have an adverse effect on the formation of the placenta and the development of the fetus. Currently, a list of drugs that are not approved for use during pregnancy has been defined.

Also of great importance in the development of placental insufficiency is thrombophilia - an increased tendency of the body to form blood clots - blood clots in the vessels. nine0013

In some cases, placental insufficiency may be due to the presence of chromosomal abnormalities in the fetus, in particular in Down syndrome (the presence of an additional chromosome 21 in the fetus) or Edwards syndrome (an additional chromosome 18 in the fetus), placental dysfunction is diagnosed already in the early stages of pregnancy.

It should be noted that among the complications of pregnancy, most often leading to the development of chronic placental insufficiency, a significant factor is preeclampsia (or late preeclampsia) - a complication of the second half of pregnancy, manifested by edema, increased pressure and the appearance of protein in the urine. nine0047 Regardless of the factors contributing to the development of placental insufficiency, it is based on circulatory disorders in the uterine-placental complex, leading to disruption of all functions of the placenta. Consequently, the symptoms of chronic placental insufficiency will be due to a lack of oxygen and nutrients to the fetus.

This is, first of all, intrauterine fetal growth retardation - a lag in the size of the fetus and a slowdown in its growth. Often there is a change in the motor activity of the fetus. At first there may be some increase in movements, and then a decrease. Violation of the protective function of the placenta leads to intrauterine infection of the fetus under the action of pathogenic (pathogenic) microorganisms penetrating the placenta. The fetus, the development of which occurs in conditions of placental insufficiency, is much more at risk of trauma during childbirth, they have a violation of adaptation to extrauterine life, increased morbidity in the first year of life. nine0013

According to the time of occurrence, doctors divide placental insufficiency into early and late.

Early (or primary) placental insufficiency

Develops before 16 weeks of gestation. It occurs already at the stage of placenta formation and is associated with diseases of a pregnant woman that are present before pregnancy, for example, with uterine pathology, chronic arterial hypertension, and endocrinological diseases. In this case, the formation of defective vessels in the placenta occurs. nine0013

Late (or secondary) placental insufficiency

Occurs after 16 weeks of pregnancy and is most often associated with diseases that have already occurred during pregnancy. Most often, these are iron deficiency anemia (that is, a decrease in the concentration of hemoglobin and iron in the blood), gestational diabetes mellitus (that is, a violation of the absorption of glucose by the body that occurred during pregnancy), past viral and bacterial infections.

It is important to subdivide placental insufficiency into compensated and decompensated forms. nine0013

Compensated placental insufficiency

It develops, for example, with the threat of abortion and mild forms of late preeclampsia, if these complications are successfully amenable to medical correction.

Decompensated placental insufficiency

Causes the development of fetal growth retardation, chronic intrauterine hypoxia, up to fetal death.

Learn more about services:

• Ultrasound for pregnant women
• Ultrasound of the 1st trimester of pregnancy
• Ultrasound of vessels during pregnancy
• Consultation with a gynecologist

Diagnosis of placental insufficiency

It is almost impossible to treat an already developed placental insufficiency, so doctors actively seek to identify pregnant women who are at risk of developing placental dysfunction. If placental insufficiency is detected in the 3rd trimester of pregnancy, there is no effective treatment, unfortunately. Therefore, all methods of identifying in the early stages of pregnancy those women whose formation of the placenta has been disturbed are being very actively used. nine0013

First of all, when registering for pregnancy, the most significant risk factors are identified - smoking, abortions, aggravated heredity (low birth weight, tendency to thrombosis), the presence of chronic diseases of the heart, blood vessels, diabetes mellitus.

Preventive measures against the development of placental insufficiency are especially relevant and necessary until 16-17 weeks of pregnancy, when the formation of placental structures occurs.

Significant assistance in assessing the risk of developing placental insufficiency is provided by prenatal screening, which is carried out at 11-14 weeks of pregnancy. It is carried out to detect Down syndrome, Edwards syndrome and other chromosomal diseases in the fetus. Currently, the most relevant is to conduct a comprehensive early screening of a pregnant woman to predict the risk of developing placental insufficiency, preeclampsia and intrauterine growth retardation. Since this type of diagnostics is one of the most modern and advanced, unfortunately, it is not yet included in the list of services provided in the antenatal clinic within the framework of compulsory medical insurance, but is available to everyone in prenatal diagnostic centers. nine0013

Determination of proteins produced by the placenta

First of all, the PAPP-A protein is determined, it is also a marker of chromosomal abnormalities of the fetus. A decrease in the concentration of PAPP-A in the blood at 11-14 weeks of gestation occurs in pregnant women who have a high risk of placental insufficiency and fetal growth retardation.

The second placental hormone that helps in assessing the risk of placental insufficiency is PIGF (placental growth factor). Its concentration in the blood decreases long before the first manifestations of placental insufficiency. Its definition is not as widely used as PAPP-A, but many laboratories have already included this protein in 1st trimester prenatal screening. It is extremely important when screening the 1st trimester to measure blood flow in the vessels of the uterus. It has been unambiguously proven that the narrowing of the vessels of the uterus, determined during the study, indicates the inferiority of the formation of the placenta, which will worsen with increasing gestational age and lead to a decrease in the nutrition of the baby and the supply of oxygen, that is, to the development of placental insufficiency and fetal growth retardation. With normal sizes of uterine vessels at 11-14 weeks of gestation, the risk of severe placental insufficiency is negligible. nine0013

The next mandatory screening ultrasound is at 20-21 weeks of gestation. In this case, measurements of the fetus must be carried out in order to assess whether there is a lag in growth. After all, with oxygen starvation, the growth rate of the fetus slows down and its size begins to lag behind the norm for each period of pregnancy. In addition, the doctor must evaluate the condition and maturity of the placenta. During ultrasound, dopplerometry of the uterine vessels is also performed to detect early changes that precede the clinical manifestations of placental insufficiency. nine0013

In patients belonging to the high-risk group, in addition to ultrasound and dopplerometry, daily monitoring of blood pressure fluctuations is also carried out, the amount of protein in the urine sample collected per day is determined, and the indicators of the blood coagulation system are evaluated.

The third ultrasound is performed for all expectant mothers at 30-34 weeks of pregnancy. The doctor measures the circumference of the head and abdomen of the crumbs, the length of the bones of his arms and legs, and calculates the estimated weight of the fetus. These measurements allow the doctor to make sure that the baby is developing normally. The structure of the placenta is also important, the presence of signs of aging in it, as a result of which it usually ceases to fully supply the baby with blood, which means that it ceases to have enough oxygen and nutrients and the development of the child is disturbed. During ultrasound, the amount and type of amniotic fluid is assessed, which can also change with intrauterine fetal suffering. nine0013

Doppler

Doppler of the placental and umbilical cord vessels (method of studying blood flow velocities in these vessels) also allows you to assess the well-being of the baby. The doctor examines the blood flow in the arteries of the uterus, umbilical cord, heart and brain of the child. This study allows you to determine whether the placenta is working well, whether there are signs of a lack of oxygen in the baby, or the development of preeclampsia in the mother. With a decrease in the speed of blood flow in any vessel, one can speak of fetal malnutrition of varying severity. nine0013

A well-timed examination makes it possible to identify the initial stages of blood supply deficiency. In such cases, treatment can prevent formidable complications, such as hypoxia and intrauterine growth retardation of the baby. Dopperometry is carried out at 20-21 weeks and at 30-32 weeks of pregnancy, if there are changes, control is carried out at least every two weeks.

Cardiotocography

This is an important method for assessing the condition of the fetus. CTG is performed at a gestational age of 33 weeks or more, since only at this stage of the intrauterine development of the baby is a complete regulation of the activity of the cardiovascular system of the fetus established by the centers of the spinal cord and brain. Recording of fetal heartbeats is carried out for 20-40 minutes, and if necessary, the study can be extended up to 1.5 hours. nine0013

The device registers and records the baby's heart rate. The obstetrician-gynecologist evaluates the heartbeat recording curve, episodes of slowing down and a sharp increase in the fetal heart rate, and based on these data, makes a conclusion about how comfortable the baby feels in the mother's stomach. For example, with a decrease in the concentration of oxygen in the blood of the fetus, its supply to the cells of the nervous system also decreases, which in turn affects the heart rate. In the normal course of pregnancy, CTG is performed after 33 weeks 1 time in 10-14 days, sometimes more often. Some clinics currently offer the service of continuous CTG monitoring, which becomes relevant in the presence of signs of placental insufficiency. A pregnant woman is given a monitor that records changes in the baby's heart activity and these data are transmitted via the Internet to the attending physician. nine0013

Treatment of placental insufficiency

There are currently no specific treatments for placental insufficiency because there are no drugs that selectively improve uteroplacental blood flow. That is why all measures to combat placental insufficiency are aimed at prevention. If the patient is at high risk for the development of placental insufficiency, from early pregnancy she is prescribed drugs whose effectiveness is well proven and which prevent the early development of severe placental dysfunction. nine0013

If during the additional methods of assessing the condition of the fetus, initial disturbances in the supply of oxygen to the baby are detected, drug treatment is carried out aimed at increasing the flow of blood and oxygen through the placenta and mandatory control examinations against the background of ongoing therapy. If the changes are serious and the baby experiences a pronounced deficiency of oxygen and nutrients, his condition suffers, then in such cases an emergency delivery is performed.

Premature placental abruption: what a future mother needs to know and how not to miss its signs | Blog

First, let's talk about what is the placenta?

The placenta is the embryonic organ that connects the body of mother and child. Its uniqueness lies in the fact that it is the only "disposable" organ. The placenta begins to develop from the 2nd week of pregnancy, forms up to 15-16 weeks and reaches full functional maturity by 36 weeks. And after the birth of the fetus (in the third stage of childbirth), it separates and leaves the mother's body, starting the process of lactation at the endocrinological level. nine0013

The placenta performs important functions such as gas exchange, nutrient exchange between mother and child, provides immunological protection and works as an endocrine gland, producing hormones necessary for the development of the fetus and the normal course of pregnancy. Every minute, about 500 ml of blood enters the placenta, but at the same time it is a kind of barrier that does not allow the blood of the mother and child to mix, and also prevents many toxic substances from entering the bloodstream of the baby. nine0013

In this article we will talk about placental abruption.

This condition is quite rare (up to 1.5% of all pregnancies), but causes such threatening complications as massive bleeding and hemorrhagic shock, fetal distress, which in some cases can cause death. Normally, the detachment of the placenta from the inner wall of the uterus occurs only after the birth of the fetus. If this happens before the onset of labor, as well as in the first or second stage of labor, this is the premature detachment of a normally located placenta. This condition is a very dangerous pathology that requires immediate diagnosis and decision of further medical tactics in the near future. nine0013

Causes of premature placental abruption

Unfortunately, the only cause of premature placental abruption has not been established to date. There are many theories, but in general, the occurrence of this condition is associated with many provoking factors.

Major risk factors include:

• arterial hypertension,
• diabetes mellitus
• pregnant woman over 40 years old
• multiple pregnancy
• polyhydramnios
• postterm pregnancy and large fetus
• previous uterine surgery
• blood coagulation disorder,
• autoimmune diseases
• kidney disease
• bad habits such as smoking and drug use
• inflammatory diseases of the uterus and placenta, anomalies in the development of the uterus.

Causes that can provoke placental abruption: physical trauma of a pregnant woman (accident, fall, blow to the stomach), disruption of the contractile activity of the uterus, stress, gross obstetric manipulations. nine0013

Types of placental abruption

There are the following types of placental abruption: partial and complete.

Partial detachment, in turn, can be central and marginal.

Why is this classification so important? And because both the clinical picture and medical tactics depend on the place and volume of the detachment. Partial detachment can be progressive or non-progressive.

Non-progressive detachment has a significantly better prognosis for a pregnant woman, because in this case, conservative treatment is possible with preservation of pregnancy. nine0013

Symptoms of placental abruption:

Here is a triad of main symptoms that may be a sign of placental abruption:

1. abdominal pain, feeling of increased uterine tone;
2. spotting from the genital tract;
3. violation of the fetal heartbeat, which indicates fetal distress.

Also, a woman can feel the baby's reaction to a decrease in the amount of oxygen supplied to him due to placental abruption - he begins to move more actively, reacting to hypoxia. nine0013

These symptoms do not always appear at the same time! For example, with marginal abruption of the placenta, blood flows into the vagina, which means that the woman sees signs of bleeding. With central detachment, a retroplacental hematoma is formed. Bleeding is internal, which means that a pregnant woman may not notice its signs. The appearance of an accelerated heartbeat in a woman, a decrease in blood pressure, nausea, dizziness, and severe weakness may indicate internal bleeding.

However, with central placental abruption, blood accumulates in front of the placenta and begins to “press” on nearby tissues. As a result, a pronounced pain syndrome occurs.

It must be emphasized that if at least one of the symptoms appears, it is necessary to immediately inform the doctor about it! This condition can be very dangerous for you and your baby, so it is important to diagnose it in a timely manner.

Diagnosis of placental abruption

Diagnosis of placental abruption is based not only on clinical symptoms and gynecological examination. Ultrasound diagnostics is the main method that allows you to accurately assess the location and area of ​​​​the exfoliated area of ​​the placenta and see the presence or absence of a hematoma. Also, ultrasound can distinguish premature detachment from placenta previa (its abnormal location, in which it overlaps the internal pharynx of the cervix). This condition can have similar symptoms, as it is often accompanied by bleeding. The condition of the fetus and the degree of its hypoxia will be determined using cardiotocography, and Dopplerography, in turn, assesses violations of the uteroplacental circulation. Based on these examination results, the obstetrician-gynecologist, and more often a council of doctors, decides on the type of further medical tactics. nine0013

Treatment of placental abruption

Treatment of placental abruption always requires hospitalization of the pregnant woman in the maternity hospital for constant monitoring of her condition. In cases of non-progressive mild placental abruption with a stable state of the mother and fetus, conservative tactics with drug therapy and preservation of pregnancy are possible. Progressive detachment, as well as severe detachment, certainly requires an emergency caesarean section. nine0013

In case of complete detachment of the placenta, with the rapid progression of this condition, massive bleeding occurs, which threatens the life of both the pregnant woman and the child. In such a situation, surgeons always prioritize the life of a woman and do everything necessary to save her. Some cases may, unfortunately, require even such radical surgical tactics as removal of the uterus. However, at the current level of development of medicine, more and more technologies are emerging that, with timely assistance, can save not only the life of the mother and child, but also the reproductive functions of a woman. In particular, our obstetrician-gynecologists and anesthesiologists use up-to-date international medical protocols to ensure the safest possible delivery. Appropriate algorithms have also been developed for surgical interventions with a high risk of bleeding. Thanks to the latest technologies in vascular surgery with X-ray and ultrasound control, massive bleeding can be quickly and safely stopped.

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