Fetus without amniotic fluid. Polyhydramnios and oligohydramnios, or how much amniotic fluid there should be. Composition of amniotic fluid

Amniotic fluid. Volume of amniotic fluid. The amount of amniotic fluid. Functions of amniotic fluid.

Amniotic fluid , or amniotic fluid, are a biologically active environment surrounding the fetus. Throughout pregnancy, amniotic fluid performs the most various functions, ensuring the normal functioning of the mother-placenta-fetus system. The amniotic sac appears in the 8th week of pregnancy as a derivative of the embryoblast. Subsequently, as the fetus grows and develops, a progressive increase in the volume of the amniotic cavity occurs due to the accumulation of amniotic fluid in it.

Amniotic fluid is mainly a filtrate of maternal blood plasma. The secretion of the amniotic epithelium also plays an important role in its formation. At later stages of intrauterine development, the kidneys and lung tissue of the fetus take part in the production of amniotic fluid.

Volume of amniotic fluid depends on the stage of pregnancy. The increase in volume occurs unevenly. So, at 10 weeks of pregnancy the volume of amniotic fluid is on average 30 ml, at 13-14 weeks - 100 ml, at 18 weeks - 400 ml, etc. The maximum volume is observed at 37-38 weeks of pregnancy, averaging 1000-1500 ml. By the end of pregnancy, the amount of water may decrease to 800 ml. During postterm pregnancy (41-42 weeks), a decrease in the volume of amniotic fluid is observed (less than 800 ml).

Amniotic fluid characterized by a high exchange rate. During a full-term pregnancy, about 500 ml of water is exchanged within 1 hour. A complete exchange of amniotic fluid occurs on average in 3 hours. During the exchange process, 1/3 of the amniotic fluid passes through the fetus, which swallows approximately 20 ml of water in 1 hour. In the third trimester of pregnancy, as a result of the respiratory movements of the fetus, 600-800 diffuses through its lungs ml of liquid per day. Until 24 weeks of pregnancy, the exchange of amniotic fluid also occurs through the skin of the fetus, and later, when keratinization of the epidermis occurs, the fetal skin becomes almost impermeable to the liquid medium.

The fetus not only absorbs the liquid environment surrounding it, but is itself the source of its formation. It has been proven that at the end of pregnancy the fetus produces about 600-800 ml of urine per day. Fetal urine is an important component of amniotic fluid.

Exchange of amniotic fluid occurs through the amnion and chorion. Along with this, an important role in water exchange belongs to the so-called paraplacental pathway, i.e. through the extraplacental part of the membranes.

Early in pregnancy amniotic fluid They are a colorless transparent liquid, which subsequently changes its appearance and properties. From transparent, it becomes cloudy due to the ingress of secretions from the sebaceous glands of the fetal skin, vellus hairs, scales of desquamated epithelium, droplets of fat and some other substances. From a chemical point of view, amniotic fluid is a colloidal solution of a complex chemical composition. The acid-base composition of amniotic fluid changes during pregnancy. It should be noted that the pH of the amniotic fluid correlates with the pH of the fetal blood.

IN amniotic fluid dissolved form contains oxygen and CO2, they contain all the electrolytes that are present in the blood of the mother and fetus. Proteins, lipids, carbohydrates, hormones, enzymes, various biologically active substances, and vitamins are also found in amniotic fluid. The detection of phospholipids in the amniotic fluid, which are part of the surfactant, is of important diagnostic importance. For a physiologically occurring full-term pregnancy, the optimal ratio between the concentration of lecithin and sphingomyelin in water is 2 (the lecithin concentration is 2 times higher than the sphingomyelin concentration). This ratio of these chemical agents is typical for a fetus with mature lungs. Under these conditions, they easily straighten during the first extrauterine breath, thereby ensuring the establishment of pulmonary respiration.

Determining the concentration of a-fetoprotein in the amniotic fluid is also important diagnostic value. This protein is produced in the fetal liver and then enters the amniotic fluid along with urine. A high concentration of this protein indicates fetal developmental abnormalities, mainly in the nervous system.

Along with this, the determination of creatinine content in the amniotic fluid, which reflects the degree of maturity of the fetal kidneys, has a known diagnostic value.

IN amniotic fluid There are factors that affect the blood coagulation system. These include thromboplastin, fibrinolysin, and factors X and XIII. In general, amniotic fluid has relatively high coagulating properties.

Amniotic fluid perform important mechanical function. They create conditions for free movements of the fetus, protect the fetal body from adverse external influences, and protect the umbilical cord from compression between the fetal body and the walls of the uterus. The amniotic sac contributes to the physiological course of the first stage of labor.

Information Amniotic fluid (amniotic fluid) is a biologically active liquid medium that is located inside the membranes, surrounds the fetus and plays an important role in ensuring its vital functions.

Main functions of amniotic fluid:

1. Fetal nutrition. The amniotic fluid contains nutrients that in the early stages are absorbed through the skin; in the later stages, the fetus itself swallows a small amount of amniotic fluid;
2. Maintaining a constant temperature(about 37 degrees Celsius) and pressure;
3. Protection of the fetus from mechanical stress. Amniotic fluid reduces the force of shocks and pressure coming from outside;
4. Protecting the fetus from infections. This function is ensured by the content of immunoglobulins in the water, as well as the tightness of the amniotic sac;
5. Ensuring free movement of the fetus;
6. Protecting the fetus from loud noise(amniotic fluid muffles sounds).

Composition of amniotic fluid quite complex and varies depending on the duration of pregnancy:

1. Proteins, carbohydrates, fats;
2. Vitamins, minerals;
3. Hormones, enzymes;
4. Oxygen, carbon dioxide;
5. Immunoglobulins;
6. Vellus hair, lubricant elements covering the body of the fetus.

Study of amniotic fluid

Basic indicators amniotic fluid of interest for diagnostic purposes:

1. Color, transparency. Normally, amniotic fluid should be light, transparent, and not contain a large amount of impurities (only single particles in the field of view);
2. Quantity. The volume of amniotic fluid changes significantly during pregnancy: it increases by 40-45 ml every day until 32 weeks, then gradually begins to decrease. By the end of pregnancy, the norm of amniotic fluid is 500-1500 ml;
3. Hormone content;
4. Cytological and biochemical composition.

Basic methods for studying amniotic fluid:

Ultrasonography

During an ultrasound, the doctor may see the transparency and amount of amniotic fluid.
The appearance of more suspensions and flakes in the amniotic fluid may indicate fetal oxygen deficiency (hypoxia) and requires mandatory treatment.

Important An important indicator is the determination of the amount of amniotic fluid, To do this, the amniotic fluid index is measured using ultrasound. The uterine cavity is conventionally divided into 4 parts and the largest free area between the uterine wall and the fetus (vertical pocket) is measured.

Normal amniotic fluid index

When amniotic fluid indicators go beyond the boundaries of these norms, we can talk about polyhydramnios or oligohydramnios.

Amnioscopy

Amnioscopy is a visual method for examining amniotic fluid using an amnioscope.

Indications for amnioscopy:

1. Post-term pregnancy;
2. Chronic fetal hypoxia.

Contraindications:

1. Fetal pelvis;
2. Inflammatory diseases of the vagina and cervix.

During amnioscopy, the color of the amniotic fluid and the presence of impurities: meconium, blood, lubricant flakes are studied.

Amniocentesis

Amniocentesis is an invasive procedure that is performed by puncturing the amniotic membranes to obtain amniotic fluid.

A sample of amniotic fluid is used for biochemical, hormonal and cytological analysis. Main indication For this procedure is the diagnosis of chromosomal diseases of the fetus.

Contraindications to amnioscopy are acute and chronic inflammatory diseases of any localization.

Under ultrasound control, a site for puncture is selected (the largest pocket of amniotic fluid free from umbilical cord loops) and about 20-25 ml of amniotic fluid is taken.

Main pathologies of amniotic fluid

For the normal development of pregnancy, amniotic fluid must be present in a certain quantity and chemical composition. Any changes in the amniotic fluid indicate the appearance of pathology:

Polyhydramnios is a pathological condition in which the amount of amniotic fluid exceeds normal levels. May leak in acute form when the amount of amniotic fluid increases sharply, and in chronic(characterized by a gradual increase in water).

Polyhydramnios is a dangerous pathology and can lead to to a number of complications during pregnancy and childbirth.

If an increase in the volume of amniotic fluid is detected, the woman must admitted to hospital.

You can learn more about the causes, clinical symptoms, complications and treatment of this pathology in the topic polyhydramnios

Low water– this is a decrease in the volume of amniotic fluid less than normal levels.

Clinical signs are not always present, so in most cases, oligohydramnios is detected by ultrasound.

Treatment of oligohydramnios practically absent: it is impossible to artificially increase the amount of amniotic fluid. All therapy is aimed at maintaining uteroplacental blood flow and improving the condition of the fetus. In severe cases, emergency delivery is indicated.

Detailed information about the course of oligohydramnios and its effect on pregnancy and the condition of the fetus is in the topic oligohydramnios.

Useful video

Amniotic fluid begins to form at 5-6 weeks, and its volume changes throughout pregnancy.

If at 5-6 weeks the volume of amniotic fluid is about 5 ml, then at the 38th week this volume is about 1 liter, and at the 40th week about 600 ml.

In this article we will look at what amniotic fluid consists of, what it is for, and what methods exist for studying amniotic fluid. We will also look at common pathologies of amniotic fluid.

Why amniotic fluid is needed

Amniotic fluid plays a vital role in the development and protection of the baby throughout pregnancy and throughout pregnancy.

• protection of the fetus from mechanical damage;
• creating conditions for fetal movement and preventing contractures of the limbs;
• prevention of adhesions;
• the presence of amniotic fluid prevents compression of the umbilical cord;
• amniotic fluid creates the necessary “purified” environment for the child and protects the fetus from infections. The volume of amniotic fluid is renewed every 3 hours, and thus this medium always remains “fresh”;
• creating conditions for the development of fetal lungs;
• fetal nutrition;
• the baby “throws out” all processed products into the amniotic fluid, and this makes it possible to remove these products through the mother’s excretory system, thereby cleansing the child’s body;
• When the time for labor approaches, amniotic fluid exerts its weight on the cervix, forcing it to open. During childbirth, amniotic fluid facilitates the movement of the baby through the birth canal.

What amniotic fluid consists of?

Throughout pregnancy, the composition and volume of amniotic fluid changes. The composition includes: epidermal scales, vellus hair and vernix lubrication of the fetus, proteins, fats, carbohydrates, enzymes, vitamins, glucose, hormones and waste products of the fetus.

Amniotic fluid, main indicators

Amount of amniotic fluid

Amniotic fluid is produced by the amnion (fetal sac) throughout pregnancy. But the amount (volume) of water is not the same at different times. The largest volume of amniotic fluid is around 36 weeks, and is about 1-1.5 liters. Conditions such as polyhydramnios and oligohydramnios are diagnosed based on the amount of amniotic fluid. The amount of water is determined by. Approximate norms for the volume of amniotic fluid (depending on the stage of pregnancy) are shown in the diagram below.

Amniotic fluid color

Normally, amniotic fluid is colorless and odorless; it is colorless, transparent, and sometimes (a normal variant) may be slightly whitish. The presence of a small amount of white flakes is also considered normal. The color of the amniotic fluid becomes clear when the water breaks out, or when water leaks. The presence of “flakes” is visible on ultrasound. When amniotic fluid leaks or leaks, the following are considered dangerous symptoms:

• unpleasant odor of water and its green color. Green “coloring” indicates oxygen starvation of the fetus and requires urgent delivery (). The waters become green because, during oxygen starvation, the child secretes original feces (meconium) into the waters, and it colors the waters in a characteristic color.
• bright yellow color indicates the development of Rh conflict, or incompatibility of mother and child by blood type. Requires urgent treatment in a hospital setting.
• red color - indicates bleeding has begun (due to premature placental abruption or other reasons). Urgent hospitalization of the pregnant woman is required, and, as a rule, urgent delivery.

At the onset of labor, the amniotic fluid may have bloody streaks (in the mostly transparent volume). This is a normal option, since micro-tears may occur when the cervix dilates.

Biochemical, cytological and hormonal composition of amniotic fluid

The composition changes throughout pregnancy, and based on the composition of amniotic fluid, experts can draw conclusions about the condition of the fetus, as well as the functioning of the mother-placenta-fetus system. Also, various genetic pathologies can be diagnosed using these indicators. To carry out the analysis, amniotic fluid must be collected; this is carried out using the amniocentesis procedure.

Transparency of amniotic fluid

A small amount of flakes in the amniotic fluid is considered normal. These “flakes” begin to be visible on ultrasound around the middle of the second trimester. Towards the end of pregnancy their number increases. These are particles of fetal skin, elements of the original lubricant.

Amniotic fluid, research methods

Ultrasound. During an ultrasound, a specialist can check the transparency and volume of amniotic fluid. The presence of a large number of flakes in the waters (in the third trimester) may be a symptom of fetal hypoxia. Based on the results of ultrasound, the amniotic fluid index is also calculated and pathologies of the amount of amniotic fluid such as polyhydramnios and oligohydramnios are diagnosed.
Amnioscopy. During the amnioscopy procedure, amniotic fluid is examined visually using an amnioscope. Amnioscopy makes it possible to evaluate the color of amniotic fluid, as well as determine the composition of impurities (meconium, lubricants, flakes, and sometimes blood). During the examination, an amnioscope is inserted into the cervix. The procedure is performed without anesthesia, on a gynecological chair. Amnioscopy is performed in general.

Indications for amnioscopy: postmaturity, chronic fetal hypoxia.

Contraindications to amnioscopy: inflammatory processes in the cervix,.
Amniocentesis.A procedure for examining amniotic fluid, in which the amniotic sac is punctured and 20-25 ml of amniotic fluid is taken for analysis. With this collection of material, it is possible to carry out hormonal, biochemical and cytological analysis of amniotic fluid. An indication for such a study may be suspicions (based on ultrasound) of genetic abnormalities of the fetus. The site for puncture is determined based on the results of ultrasound (the largest “free” pocket of amniotic fluid, without umbilical cord loops).

Of the listed research methods, ultrasound and amnioscopy are non-invasive methods (without a puncture), and amniocentesis is an invasive method.

Amniotic fluid, pathologies

Such pathologies are diagnosed based on the volume of amniotic fluid.

• Polyhydramnios is a pathology of amniotic fluid, during which the amniotic fluid exceeds the norm in volume. In domestic medical practice, a volume of 1.5 liters is considered the norm (for a normal full-term pregnancy). In foreign practice, - 2 liters. Polyhydramnios can be acute or chronic (depending on the course and progression of symptoms). You can read in detail about the consequences, symptoms, diagnosis and causes of this pathology in the article.
• Oligohydramnios is a pathology of amniotic fluid, in which the volume of amniotic fluid (in advanced pregnancy) is less than 500 ml (in domestic medical practice) and less than 300 ml in foreign practice.There are moderate and severe oligohydramnios. To make a diagnosis (according to ultrasound), the doctor calculates the so-called “amniotic fluid index”, AFI. According to the timing of occurrence, oligohydramnios can occur in the first, second, and third trimester. You can read in detail about the consequences, symptoms, diagnosis and causes of this pathology in the article.

While the baby is growing in the mother's belly, he is surrounded by amniotic fluid, in which he floats freely throughout the entire period of pregnancy. The rupture of amniotic fluid indicates the onset of labor. How important is the amount of this fluid for a child's life? Let's try to figure it out.

The main function of water is protective. They smooth out sudden movements from the outside that could harm the unborn child, and also protect the umbilical cord so that the fetus does not press it against the wall of the uterus and the blood flow does not stop. Amniotic fluid plays an important role in the child's metabolism. They deliver nutrients, hormones and immunoglobulins and remove metabolic products from the body - urine, hairs, skin flakes, etc. In addition, it is the amniotic fluid that is actively involved in the process of childbirth - firstly, it makes contractions less painful, as it serves as a natural buffer, and secondly, the lower waters (located under the baby’s head, if he is in the most common cephalic presentation) press from the inside onto the uterus, causing it to open faster and better.

Amniotic fluid renewal

Amniotic fluid (or amniotic fluid) is a non-static substance. They are constantly renewed, “waste”, “polluted” waters are removed from the body, and their place is taken by renewed ones. The inner surface of the placenta and the fetal membranes are involved in the formation of amniotic fluid. And even the child himself influences the amount of amniotic fluid, since it is he who swallows the fluid surrounding him and secretes urine.

The process of water exchange occurs continuously - they are completely renewed within 3 hours.

A serious complication of pregnancy is leakage of amniotic fluid. Signs of amniotic fluid leakage may go unnoticed. A woman may mistake wetness on her underwear for sweat or vaginal discharge. Do not draw conclusions on your own; describe the situation to your gynecologist in detail. When amniotic fluid leaks, there is a risk of infection for mother and child.

Amount of amniotic fluid: polyhydramnios and oligohydramnios

The amount of amniotic fluid is not the same throughout pregnancy. In the first 18-20 weeks, their volume is proportional to the size of the child. Towards the end of pregnancy, the normal amount of water is from 600 to 1500 ml. It is for the purpose of determining the amount of amniotic fluid that women are recommended to have an ultrasound scan at 37-38 weeks, since deviations from these parameters can have a detrimental effect on the health of the mother and child.

Polyhydramnios during pregnancy

Polyhydramnios during pregnancy is a situation when the amount of amniotic fluid in the amniotic fluid exceeds 1.5 - 2 liters. You can notice the symptoms that this is happening even externally - in women with polyhydramnios, as a rule, the abdomen grows very much, and many “stretch marks” appear on the skin. During the examination, it is necessary to resort to additional examination methods, since it is difficult for the doctor to determine the location of the organs in the fetus and hear the heartbeat. The woman finds it difficult to breathe, her pulse quickens, and her legs become very swollen.

Complications of polyhydramnios during pregnancy

Pregnancy becomes a heavy burden for the mother in the literal sense of the word, and the child is completely exposed to a mortal threat. Since too much space allows for additional movements, and at this time the umbilical cord can wrap around the cervix. Also, the presence of excess amniotic fluid can lead to incorrect presentation - breech or transverse.

An increased amount of amniotic fluid is often discharged before term, which provokes premature birth. But since the uterus itself was too swollen during pregnancy, it may contract worse, which will lead to a weakening of labor. In this case, labor may be delayed, which negatively affects both the health of the mother and the condition of the child; both may experience hypoxia (lack of oxygen in the blood).

Causes of polyhydramnios during pregnancy

There may be several reasons for the increase in the amount of amniotic fluid. Basically, polyhydramnios is caused by infections suffered at different stages, disrupting the functioning of the amnion, disturbances in the development of the fetus (most often the nervous and digestive system, when the baby either does not swallow enough or secretes too much fluid), as well as feto-placental insufficiency, when the placenta does not produces amniotic fluid in the required quantity. Polyhydramnios often occurs in women suffering from diabetes mellitus, or during pregnancy aggravated by Rh conflict.

Pregnant women whose studies have determined polyhydramnios should be constantly under the supervision of specialists.

Ultrasound during pregnancy detects polyhydramnios

If you have been diagnosed with polyhydramnios, you will need additional ultrasound diagnostics, since ultrasound is the best way to determine the amount of amniotic fluid and identify possible fetal malformations. If polyhydramnios is not pronounced, does not interfere with the woman and does not impair blood circulation, the pregnancy continues until its natural completion, and to the expectant mother treatment of the cause that caused the increase in the amount of water is proposed. Most often this is an infection in the body, in which case the doctor will prescribe antibiotics. If the problem is other health problems (such as diabetes, or Rhesus conflict), these are the ones that are treated.

Oligohydramnios during pregnancy

Oligohydramnios is much less common than excessive amniotic fluid. Oligohydramnios is a condition when the amount of amniotic fluid is less than 500 ml. The expectant mother herself can notice and feel it: the belly is growing poorly, prints of parts of the child’s body can even be visible on the outside, the baby’s movements cause pain. Low water also has a negative effect on the fetus itself: the wall of the uterus is too close, they compress both the child and the umbilical cord. Because of this, the baby lags behind in development, he is too small and weak, his skin becomes dry and covered with unnecessary folds. Possible defects of the musculoskeletal system - curvature of the spine, torticollis, clubfoot and others.

Causes of oligohydramnios during pregnancy

Typically, oligohydramnios during pregnancy occurs due to insufficient functioning of the amnion (fetal membrane), which, as with polyhydramnios, can be caused, for example, by an infectious process in the pregnant woman’s body. The amount of amniotic fluid may decrease if the child’s development is impaired, especially with defects of the kidneys and excretory systems, as well as in the case of fetal hypoxia, since at this time the fetus also produces little urine. Oligohydramnios can occur in one of the identical twins if the second is characterized by polyhydramnios. This happens when the blood circulating from the common placenta is distributed unevenly. The amount of water decreases during post-term pregnancy. Smoking during pregnancy also causes oligohydramnios.

Treatment of oligohydramnios during pregnancy

Treatment of oligohydramnios is carried out in almost the same way as in the case of polyhydramnios. The woman is under constant medical supervision, and in case of serious suffering for her and/or the child, early delivery is offered. If mother and child feel well, spontaneous birth on time is possible. However, with both excess and insufficient amounts of amniotic fluid, labor rarely begins spontaneously; usually the woman undergoes a puncture of the amniotic sac, since a large amount of water interferes with the contraction of the uterus, and with oligohydramnios, the flat amniotic sac does not open the uterus from the inside. In extreme cases, if the umbilical cord is entangled, the fetus is positioned incorrectly, or the condition of mother and child is extremely serious, a caesarean section will be performed. However, we wish you that your birth proceeds in accordance with the norms, and that problems do not frighten you.

Throughout pregnancy, amniotic fluid performs a wide variety of tasks, ensuring the normal functioning of the mother-placenta-fetus system. The successful outcome of pregnancy largely depends on the quantity and quality of amniotic fluid.

Amniotic fluid (the scientific name for amniotic fluid) is basically a filtrate from the mother's plasma (the fluid part of the blood). The secretions of the cells lining the fetal bladder from the inside also play an important role in its formation. The fetus not only absorbs the liquid environment surrounding it, but is itself the source of its formation, since in the later stages of intrauterine development the kidneys and lung tissue of the fetus take part in the production of amniotic fluid. It has been proven that at the end of pregnancy, every day the fetus secretes about 600-800 ml of urine, which is an important component of the amniotic fluid.

The volume of amniotic fluid depends on the duration of pregnancy. The increase in volume occurs unevenly. In, in, the amount of amniotic fluid is on average 30 ml, in - about 100 ml, in - 400 ml, etc. The maximum volume is observed at , averaging 1000-1500 ml. By the end of pregnancy, the amount of water may decrease to 800 ml as a result of increased fluid excretion from the woman’s body.

Amniotic fluid performs a number of important functions. They create conditions for the free movement of the fetus, protect its body from adverse external influences, and protect the umbilical cord from compression between the fetal body and the walls of the uterus. Thus, the volume of amniotic fluid is a kind of indicator of the normal course of pregnancy.

What is oligohydramnios?

Diagnosis of oligohydramnios

The doctor can assume a decrease in the amount of amniotic fluid if the height of the fundus of the uterus (its uppermost part) and abdominal circumference lag behind the normative indicators for the expected period of pregnancy, as well as if the motor activity of the fetus decreases. During external examination, parts of the fetus are clearly identified, heart sounds are heard, and the uterus is dense. A more accurate determination of the severity of oligohydramnios is possible with ultrasound examination.

The diagnosis of oligohydramnios by ultrasound is based on determining the amount of amniotic fluid and on calculating the amniotic fluid index (AFI), which is automatically calculated by the ultrasound machine after measuring the amount of fluid in several places. The amount of amniotic fluid is considered normal if the IAF value is between 5 and 8 cm; An AFI of 2 to 5 cm is regarded as moderate oligohydramnios, an AFI of less than 2 cm is considered as severe oligohydramnios.

A Doppler study of blood flow in the “mother-placenta-fetus” system, which is carried out in the umbilical cord artery, in the middle cerebral artery of the fetus and both uterine arteries of pregnant women, is also necessary, because With oligohydramnios, there may be a disturbance in blood flow.

As the amount of amniotic fluid decreases, the frequency of pronounced forms of fetal growth retardation (hypotrophy) increases, determined using ultrasound fetometry - the most reliable objective method for assessing the growth and development of the fetus, which allows, at each specific stage of pregnancy, to accurately determine the correspondence of the size of the fetus to this period, as well as the degree their deviations from normal indicators. With I degree of malnutrition, there is a lag of fetometry indicators from the normative indicators by , with II - by , with III - by more than . Newborns born to mothers with severe oligohydramnios often show signs of hypotrophy of varying degrees. Sometimes, with severe oligohydramnios, premature “ripening” of the placenta is detected (a condition in which the placenta begins to “prepare” for childbirth earlier than necessary, as a result of which its functions are disrupted), which leads to a deterioration in the condition of the fetus. In most pregnant women with oligohydramnios, Doppler examination of the state of blood flow shows changes in its indicators. To clarify, cardiotocography (CTG) - recording the fetal heartbeat - is a modern method for diagnosing the intrauterine condition of the fetus, which is carried out after 32 weeks of pregnancy.

There are also primary oligohydramnios, which develops when the membranes are intact, and secondary, or traumatic, associated with damage to the membranes and the gradual flow of amniotic fluid - the woman may not feel this. Elements of amniotic fluid can be detected when examining vaginal discharge; the so-called amniotest is the most effective and fastest method for diagnosing premature rupture of membranes, based on the determination of placental protein in the vaginal discharge. Normally, this protein is not present in vaginal discharge. If the flow of water is significant, the woman feels discomfort from the fact that her underwear periodically becomes wet from the water. If leakage of amniotic fluid (premature rupture of the membranes) is detected during a premature pregnancy, the woman must be hospitalized in a separate room, bed rest and mandatory monitoring of the health of the mother and fetus to decide on further tactics for managing the patient. If the pregnancy is full term, then in the absence of contractions, labor stimulation begins.

What is oligohydramnios like?
There are two forms of oligohydramnios:

• early, which is caused by functional insufficiency of the membranes. This form is diagnosed using ultrasound examination at term;
• late, usually detected after, when oligohydramnios occurs due to insufficient functional activity of the membranes or disturbances in the condition of the fetus.

Why is oligohydramnios dangerous?

An extremely unfavorable prognostic sign is the detection of severe oligohydramnios in the second trimester of pregnancy, i.e. on timing. When oligohydramnios develops during these periods, pregnancy is terminated and intrauterine death of the fetus or newborn occurs in the first days of life. During this period, the fetal body is not yet adapted to independent extrauterine existence, and special equipment is needed to support the life of the newborn, but the earlier the pregnancy is terminated, the more unfavorable the prognosis.

As mentioned above, insufficient amniotic fluid, especially severe oligohydramnios, is a marker of an unfavorable course of pregnancy. If there is a suspicion of the development of oligohydramnios, it is necessary first of all to exclude fetal malformations (using ultrasound), since the relationship between these pathologies has been proven. But oligohydramnios itself (its pronounced forms) can lead to the development of intrauterine defects (the occurrence of adhesions between the skin of the fetus and the aqueous membrane, which lead to entanglement of parts of the fetus and the umbilical cord and interfere with the normal growth and development of the fetus). With a decrease in the amount of amniotic fluid, there is a high risk of umbilical cord compression and intrauterine fetal death, as well as intrauterine infection. All of these complications often dictate the need for early delivery by cesarean section at any stage of pregnancy if there is a risk to the woman’s health.

With moderate oligohydramnios, quite often children are born with malnutrition of varying degrees of severity (discrepancy between the size of the newborn and the given stage of pregnancy). But at the same time, the outcome of pregnancy is favorable for the vast majority of women - children are born in satisfactory condition.

Management of pregnancy and childbirth during oligohydramnios

The management of pregnancy and childbirth largely depends on the time of occurrence and severity of oligohydramnios. If oligohydramnios is detected before, then the woman needs a comprehensive examination (hormonal, biochemical, ultrasound) to determine the condition of the fetus. If fetal malformations are detected, the pregnancy is terminated for medical reasons. If oligohydramnios is detected at the beginning of the third trimester of pregnancy in combination with intrauterine growth restriction, the outcome of the pregnancy is difficult to predict. In this regard, in case of oligohydramnios, especially when combined with intrauterine growth retardation, early delivery is carried out.

Pregnant women with oligohydramnios are prescribed complex therapy aimed at improving uteroplacental blood flow, metabolic processes in the placenta, restoring gas exchange in the mother-placenta-fetus system and treating the underlying disease. During treatment, an ultrasound is performed every 7-10 days, Dopplerography of blood vessels in the “mother-placenta-fetus” system is performed once every three days, and cardiac monitoring of the condition of the fetus is performed daily. If there is no result of outpatient treatment or if the condition of the fetus worsens, hospitalization in a hospital is necessary for constant monitoring and determination of further pregnancy management tactics.

If the fetal condition deteriorates according to cardiotocography data and indicators of fetal-placental blood flow, delivery is carried out by cesarean section on an emergency basis.

If a flat membrane is detected during childbirth, when there is no amniotic fluid in front of the baby's head or there is little of it, as a result of which the fetal bladder does not wedge into the cervix during childbirth, an amniotomy is performed (artificial opening of the fetal bladder). This is necessary for the further development of labor, because a flat amniotic sac delays the normal course of labor - the dilatation of the cervix.

Thus, the health of the unborn child with oligohydramnios depends on the degree of reduction in the amount of amniotic fluid, the severity of intrauterine retention, the duration of pregnancy, the effectiveness of the therapy and the method of delivery.

Polyhydramnios

Polyhydramnios is a condition characterized by excessive accumulation of amniotic fluid. With polyhydramnios, the amount of amniotic fluid exceeds 1.5 liters and can reach 2-5 liters, and sometimes more. The causes of polyhydramnios are not fully understood, but more often polyhydramnios is observed in diabetes mellitus (a disease in which glucose metabolism is impaired), the presence of an acute or chronic infectious process in the mother, (the presence of a positive Rh factor in the mother and negative in the fetus, the development of antibodies to fetal red blood cells), multiple pregnancies, fetal development abnormalities.

One of the causes of polyhydramnios is a dysfunction of the cells lining the inner surface of the fetal aqueous membrane, which leads to an increase in the production of amniotic fluid and a delay in its excretion. It is believed that in this case, infectious (including viral) diseases of the pregnant woman (mycoplasmosis, cytomegalovirus infection, syphilis, acute respiratory diseases) are of great importance. As already mentioned, polyhydramnios often accompanies fetal developmental defects. With malformations, the fetus does not swallow amniotic fluid - this is the main mechanism that regulates the amount of amniotic fluid and thereby prevents polyhydramnios. The most common malformations with polyhydramnios are congenital malformations of the central nervous system and gastrointestinal tract fetus

There are acute and chronic polyhydramnios. Chronic develops gradually, so a pregnant woman has time to adapt to this condition and, as a rule, does not experience discomfort from an enlarged uterus. Acute polyhydramnios occurs quickly, and in this case the pregnant woman complains of shortness of breath (due to the high position of the diaphragm), general weakness, increased heart rate, and swelling. As a rule, acute polyhydramnios develops into more early dates pregnancy - in. Unlike acute polyhydramnios, with chronic polyhydramnios the intrauterine pressure does not exceed normal. If fetal malformations are excluded, foci of infection are treated, and further progression of polyhydramnios is prevented, then the condition of the fetus under these conditions does not suffer and the baby is born healthy.

Diagnosis of polyhydramnios

With the development of polyhydramnios, a significant increase in the size of the uterus is observed: the abdominal circumference and the height of the uterine fundus (the distance from the womb to the fundus of the uterus) significantly exceed those at the expected stage of pregnancy. The uterus is tense, parts of the fetus are difficult to palpate, while the fetus easily changes its position, and its excessive motor activity may be observed. Fetal heart sounds are not heard clearly.

In the diagnosis of polyhydramnios, an important role belongs to ultrasound examination. During the study, the size of the vertical pocket is determined (ultrasound criterion for assessing the amount of amniotic fluid): with a mild degree of polyhydramnios, its value is 8-11 cm, with a moderate degree - 12-15 cm, with severe polyhydramnios this figure reaches 16 cm or more. If the diagnosis of polyhydramnios is established, then it is necessary to exclude the presence of possible fetal malformations using additional research methods, in particular amniocentesis - taking a small amount of amniotic fluid (by puncture of the anterior abdominal wall, uterine wall) for biochemical, hormonal, immunological, genetic research. Determining the concentration of alpha-fetoprotein in the amniotic fluid is of great diagnostic importance. This protein is produced in the fetal liver and then enters the amniotic fluid along with urine. A high concentration of alpha-fetoprotein indicates fetal developmental abnormalities, mainly in the nervous system. Amniocentesis is always performed under ultrasound guidance. The most important information about the condition of the fetus can be obtained from the results of direct examination of its blood obtained by taking it from the umbilical cord (cordocentesis). This procedure is carried out strictly according to indications, such as diagnosis of congenital and hereditary pathologies, intrauterine infection, etc. Cordocentesis is performed after 18 weeks of pregnancy under ultrasound guidance.