The amniotic fluid index has decreased. Increased amount of amniotic fluid
During the first pregnancy, many are faced with such a concept as the amniotic fluid index, abbreviated AFI. To fully understand what it is and how important it is to adhere to the IAI standards, it is necessary to consider all aspects of this issue.
Ultrasound amniotic
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table why why
Amniotic fluid is the official name for the amniotic fluid in the womb of a pregnant woman, which provides the biological environment for the normal development of the baby.
The main functions of the biological environment.
- Child nutrition. The composition of amniotic fluid contains many necessary and beneficial substances for the fetus. During maturation, they enter the child's body by absorption through the skin. As the degree of maturity, the baby begins to independently consume the required amount.
- Ensuring normal pressure as well as temperature.
- Protection of the fetus from external environmental factors.
- The composition of amniotic fluid includes the required amount of immunoglobulin fractions, which create a sterile barrier, preventing infections. This is due to the fact that amniotic fluid has the ability to constantly renew itself, the process will stop after childbirth.
- An important factor is the complete sealing of the bladder, as well as the movement of the fetus in space.
Table of values
Various modulations of the norms of the index of AF-amniotic fluid by weeks indicates the development of an anomaly or pathology in the fetus. To avoid adverse situations, pregnant women need to be constantly examined.
Checking with a gynecologist
For the correctness of the diagnostic results, doctors carry out a number of preparatory measures.
- Analysis of the cytological and biochemical composition of amniotic fluid.
- Checking transparency, shade AJ.
- Accounting for the contained hormones.
- Checking, studying the volume. The gestational period affects the volume of amniotic fluid, which is calculated relative to the trimesters of pregnancy.
There is a special table that lists the norms of the index of AF-amniotic fluid by week in mm.
| Pregnancy (weeks) | Lower limit of normal | Mean | Upper limit of normal |
| 16 | 73 | 121 | 201 |
| 17 | 77 | 127 | 211 |
| 18 | 80 | 133 | 220 |
| 19 | 83 | 137 | 225 |
| 20 | 86 | 141 | 230 |
| 21 | 88 | 143 | 233 |
| 22 | 89 | 145 | 235 |
| 23 | 90 | 146 | 237 |
| 24 | 90 | 147 | 238 |
| 25 | 89 | 147 | 240 |
| 26 | 89 | 147 | 242 |
| 27 | 85 | 156 | 245 |
| 28 | 86 | 146 | 249 |
| 29 | 84 | 145 | 254 |
| 30 | 82 | 144 | 258 |
| 31 | 79 | 144 | 263 |
| 32 | 77 | 143 | 269 |
| 33 | 74 | 142 | 274 |
| 34 | 72 | 140 | 278 |
| 35 | 70 | 138 | 279 |
| 36 | 68 | 135 | 279 |
| 37 | 66 | 132 | 275 |
| 38 | 65 | 127 | 269 |
| 39 | 64 | 123 | 255 |
| 40 | 63 | 116 | 240 |
| 41 | 63 | 110 | 216 |
| 42 | 63 | 110 | 192 |
As can be seen from the table, the calculation principle is quite simple. For example, you need to know the rate of the amniotic fluid index at 19 weeks of pregnancy. The values in the table show 83-137-225 where the first value is the minimum, followed by the average and then the maximum allowed.
At 20-21 weeks, the lowest limit of the AF index - amniotic fluid is 86-88, this is a deviation from the norm. With such indicators, you should be observed by a doctor.
There are two ways to diagnose IAI.
- Subjective: examination with ultrasound, when longitudinal and transverse scanning is performed.
- Objective: the diagnostician, using the method of certain calculations, summarizes 4 indicators that determine the amniotic fluid index by week in cm. At week 16, it amounts to a value of 12 cm.
This is what a baby looks like in the womb
Additionally, the size of the amniotic fluid pocket is diagnosed, which is determined in two perpendicular planes. An additional test analysis is possible, which is carried out at 16-18 weeks.
Such an analysis is useful for the timely detection of anomalies, pathologies in the development of the fetus or placenta. After diagnosing the body of a pregnant woman, doctors take the necessary measures. In rare acute cases, termination of pregnancy is recommended.
Possible risks when a problem is discovered
The discrepancy between the norms of the amniotic fluid index by week of pregnancy indicates the occurrence of polyhydramnios or oligohydramnios in a woman. The manifestation of such conditions is quite dangerous, even threatens with serious complications.
Dangers with polyhydramnios:
- placental abruption is possible;
- development of infection of the birth canal;
- violation of the development of the fetus;
- possible miscarriage.
Most often, oligohydramnios is detected after 26-30 weeks or when overdue at 41 weeks. In addition, oligohydramnios threatens with serious diseases of the fetus.
Ultrasound procedure
If the index of AF-amniotic fluid at 31 weeks is 66, with an average value of 14 cm at 31 weeks, then you need urgent specialist intervention.
Dangers with oligohydramnios:
- disorders of the respiratory, genitourinary system;
- hypodynamics and pressure on the fetus, which can cause various anomalies: changes in the weight of the fetus, dislocations, deformities of the bones, spine;
- the occurrence of hypoxia;
- the possibility of premature miscarriage;
- risk of bleeding after childbirth.
Excess amniotic fluid (polyhydramnios) is detected in 1 to 3% of women in labor. For example, at week 34, your IAI is more than 278 units, this indicates a critical level of amniotic fluid. The causes of polyhydramnios are influenced by the presence of certain factors.
From the mother's side:
- Rh factor, blood type;
- the presence of diabetes;
- the presence of infections or inflammatory processes in the body.
According to the analysis of the placenta:
- in the event of a benign tumor of the fetal membrane;
- with placental edema.
Fetal diagnosis:
- multiple pregnancy;
- hereditary pathologies or diseases.
Causes of oligohydramnios:
- abnormalities of the fetus inside the womb;
- various pathologies: infections, chromosomal abnormalities, poor fetal development, etc.;
- the presence of diseases in a woman: problems with the heart, blood vessels, inflammatory and infectious symptoms, kidney disease;
- placental insufficiency, defects, heart attack;
- gestation of the fetus;
- placental abruption;
- premature death of the child inside the womb.
People in white coats
Polyhydramnios is of a different nature.
- In a moderate condition, the size of the inner pocket is from 7 cm to 18.
- With pronounced polyhydramnios, the value manifests itself in the range from 18 to 24 cm.
- In chronic, the rate is slightly higher, but stable.
- In borderline and acute conditions, the index value varies between the average and the highest. In this case, inpatient treatment is recommended.
- With an acute excess of fluid, specialists will prescribe an amniotomy, with a chronic one - a complex therapeutic treatment.
These recommendations also apply to oligohydramnios, with acute symptoms, a pregnant woman will be offered inpatient treatment. For example, your amniotic fluid index is 5 5, which indicates critical oligohydramnios, which can be a threat to the life of the fetus.
- everyone, without exception, is prescribed Curantil, Actovegin;
- minimum physical activity;
- healthy diet, diet in combination with a vitamin complex;
- preventive treatment for insurance against the formation of infectious and inflammatory processes;
- when overwearing - stimulation of childbirth.
As the baby grows
In traditional treatment, antibiotics are usually used to restore hypodynamic functions. For various infections, immunomodulators are prescribed. Diuretics are required.
Optimal treatment
The optimal treatment is determined individually for each pregnant patient, taking into account the diagnosis, characteristics and cause of the problem.
Let's say you are 32 weeks pregnant and your amniotic fluid index is 77. This means that you have borderline oligohydramnios.
Polyhydramnios and oligohydramnios are far from a tragedy, but with oligohydramnios, you will have to spend most of the time on conservation in a hospital.
With proper medication and strict adherence to the doctor's recommendations, the level of polyhydramnios will decrease, and the value of oligohydramnios will increase to the desired numbers. In this case, your AF index - amniotic fluid will be kept at a stable value.
Good mood, positive emotions, positive attitude, strict adherence to all recommendations of doctors guarantees minimal risk to the health of the mother and the normal development of the child.
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Amniotic fluid begins to form at a period of 5-6 weeks, and during pregnancy, their volume changes.
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 it is about 600 ml.
In this article, we will consider what amniotic fluid consists of, what they are for, what methods for studying amniotic fluid exist. We will also analyze common pathologies of amniotic fluid.
Why amniotic fluid is needed
Amniotic fluid plays a crucial role in the development and protection of the baby throughout pregnancy and in.
- protection of the fetus from mechanical damage;
- creating conditions for the movement of the fetus and preventing contractures of the limbs;
- adhesion prevention;
- the presence of amniotic fluid prevents squeezing of the umbilical cord;
- amniotic fluid creates the necessary "purified" environment for the child, protects the fetus from infection. The volume of amniotic fluid is renewed every 3 hours, and thus this medium always remains "fresh";
- creating conditions for the development of the lungs of the fetus;
- fetal nutrition;
- the baby "throws out" all the 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 of birth comes, the amniotic fluid with its weight acts on the cervix, forcing it to open. During childbirth, amniotic fluid makes it easier for the baby to move through the birth canal.
What is amniotic fluid made of
Throughout pregnancy, the composition and volume of amniotic fluid changes. The composition includes: epidermal flakes, vellus hair and the original lubricant 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 bladder) throughout pregnancy. But the amount (volume) of water is not the same at different times. The largest volume of amniotic fluid is at about 36 weeks, and is about 1-1.5 liters. By the amount of amniotic fluid, such conditions as polyhydramnios and oligohydramnios are diagnosed. The amount of water is determined by . Approximate norms for the volume of amniotic fluid (depending on the gestational age) are shown in the diagram below.
amniotic fluid color
Normally, amniotic fluid is colorless, odorless, colorless, transparent, sometimes (normal variant) may be slightly whitish. Also, a small amount of white flakes is considered a normal indicator. The color of the amniotic fluid becomes clear when the water is poured out, or when the water leaks. The presence of "flakes" can be seen on ultrasound. With the outflow or leakage of amniotic fluid, dangerous symptoms are:
- the unpleasant odor of the waters and their green color. Green "color" indicates oxygen starvation of the fetus, and requires urgent delivery (). Green waters become because, during oxygen starvation, the child releases original feces (meconium) into the waters and it colors the waters in a characteristic color.
- bright yellow color - indicates the development of the Rhesus conflict, or incompatibility of the mother and child in terms of blood groups. Requires urgent treatment in a hospital.
- red color - indicates the onset of bleeding (due to premature detachment of the placenta or for other reasons). Urgent hospitalization of the pregnant woman is required, and, as a rule, urgent delivery.
At the beginning of labor, the amniotic fluid may have bloody streaks (in the main transparent volume). This is a variant of the norm, since micro-tears can occur when the cervix opens.
Biochemical, cytological and hormonal composition of amniotic fluid
The composition changes during pregnancy, and according to the composition of the amniotic fluid, specialists can draw conclusions about the condition of the fetus, as well as about the work of the mother-placenta-fetus system. Also, according to these indicators, various genetic pathologies can be diagnosed. For analysis, amniotic fluid sampling is needed, it 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. By the end of pregnancy, their number increases. These are particles of the skin of the fetus, 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 amount of flakes in the waters (in the third trimester) may be a symptom of fetal hypoxia. According to the results of ultrasound, the amniotic fluid index is also calculated and such pathologies of the amount of amniotic fluid as polyhydramnios and oligohydramnios are diagnosed.
Amnioscopy. During the amnioscopy procedure, amniotic fluid is examined visually using an amnioscope. Amnioscopy makes it possible to assess the color of amniotic fluid, as well as to determine the composition of impurities (meconium, lubricants, flakes, 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 with a whole.
Indications for amnioscopy: gestation of the fetus, chronic fetal hypoxia.
Contraindications to amnioscopy: inflammatory processes in the cervix,.
Amniocentesis.The procedure for the study of amniotic fluid, in which the fetal bladder is pierced and 20-25 ml of amniotic fluid is taken for analysis. With such a sampling of material, it is possible to conduct a hormonal, biochemical and cytological analysis of amniotic fluid. An indication for such a study may be suspicions (according to ultrasound) of genetic abnormalities of the fetus. The place 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, pathology
By the volume of amniotic fluid, such pathologies are diagnosed.
- Polyhydramnios is a pathology of amniotic fluid, during which amniotic fluid exceeds the norm in volume. In domestic medical practice, a volume of 1.5 liters is considered the norm (with a normal full-term pregnancy). In foreign practice, - 2 liters. Polyhydramnios can be acute and chronic (depending on the course and increase in 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 (with advanced pregnancy) is lower 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 data), the doctor calculates the so-called “amniotic fluid index”, IAF. 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.
Amniotic fluid (oligohydramnios and polyhydramnios)
amniotic fluid- this is a liquid biologically active medium that fills the cavity of the fetal bladder formed by the membranes, surrounds the fetus during its development in the mother's body and is a product of secretory activity amnion(embryonic membrane).
The intensive exchange of amniotic fluid and the complexity of the chemical composition, along with the placenta, ensure the normal intrauterine development of the fetus. Changes in the composition and amount of amniotic fluid not only reflect organic and functional disorders of the feto-placental complex, but also accompany pathological processes in the mother and fetus.
Despite the great interest shown in the study of amniotic fluid, the mechanism and source of their formation is not yet completely clear. According to some authors, the first portion of amniotic fluid is the result of secretion chorion(i.e., the outer germinal membrane that surrounds the embryo and is formed in the initial stages of gestation), as evidenced by their visualization at the 3rd week of pregnancy. Starting from the 5th week, amniotic fluid is included in the amniotic fluid, the amount of which progressively increases. Until the 13th - 14th week of pregnancy, amniotic fluid is the result of the secretion of the amniotic membrane.
According to modern concepts, in the second trimester of pregnancy, the main component of amniotic fluid is maternal plasma transudate, which penetrates the placenta. It is also known that, starting from the II trimester, the amniotic fluid is partially replenished by the urine of the fetus. Amnion cells, the umbilical cord, and the lungs of the fetus are also involved in the formation of amniotic fluid. From the 16th week of intrauterine development, the overall increase in the amount of amniotic fluid occurs due to a slightly larger release of fluid through the kidneys and lungs compared to the ingestion of them by the fetus.
In the third trimester, fetal diuresis is of some importance in the formation of amniotic fluid and amounts to 500-600 ml per day by the end of pregnancy. At the same time, resorption of amniotic fluid occurs, part is absorbed by the fetus (up to 400 ml of amniotic fluid), part enters the body of the pregnant woman through the fetal membranes. The main amount of fluid is removed from the amniotic cavity by the paraplacental route.
Amniotic fluid containing metabolic products enters through the amnion wall, intercellular spaces and blood vessels of the smooth chorion into the decidua parietalis and from it into the venous system of the pregnant woman. Amniotic fluid is completely renewed every 3 hours. Their amount depends on the duration of pregnancy and ranges from 300 ml to 1.5 liters. So, according to S. Campbell, K. Liz (2004), at 10 weeks. the volume of amniotic fluid is 30 ml, at the 20th week - 300 ml, at the 30th week - 600 ml, at the 38th week - 1000 ml, at the 40th week - 800 ml, at the 42nd week - 350 ml. The decrease in the volume of amniotic fluid during postmaturity does not yet have a clear explanation.
Amniotic fluid performs a number of important functions that ensure the normal development of the fetus:
- protection of the fetus from mechanical damage;
creating conditions for fetal movements and preventing contractures of the limbs;
prevention of adhesions between the fetus and the amnion;
creation of conditions for the development of the lungs of the fetus, when the fluid in the bronchioles of the fetus moves in two directions (the absence of amniotic fluid in the second trimester of pregnancy leads to lung hypoplasia).
oligohydramnios. The amount of amniotic fluid less than 500 ml is called oligohydramnios or oligohydramnios, and their complete absence is called anhydramnios. According to modern literature data, the prevalence of oligohydramnios ranges from 0.3 to 5.5%. With congenital malformations of the fetus, this condition occurs 10 times more often. The widespread introduction of the ultrasound method of prenatal diagnosis into clinical practice has increased the detection of oligohydramnios during pregnancy.
Usually oligohydramnios is explained:
- insufficient development of the epithelium lining the amniotic membrane, or damage to its secretory function;
according to some authors, oligohydramnios occurs against the background of hypertension, and the frequency of development and the severity of oligohydramnios depend on the duration of the course of vascular pathology and the degree of its compensation; in hypertension, oligohydramnios is often combined with fetal hypotrophy;
causes of oligohydramnios can be infectious-inflammatory extragenital and gynecological diseases of the mother - 40%, metabolic disorders (obesity III degree) - 19.6%, fetoplacental insufficiency and abnormalities of the urinary system in the fetus.
- early oligohydramnios - diagnosed by ultrasound in terms of 18 to 24 weeks; it is due to the functional failure of the fetal membranes;
- late oligohydramnios - diagnosed by ultrasound after 24-26 weeks, when oligohydramnios occurs due to hydrorrhea due to partial rupture of the membranes.
According to E.N. Kondratieva(1999), a decrease in the volume of amniotic fluid at various stages of pregnancy is due to three pathogenetic options:
- parietal membranitis, which is characterized by inflammatory changes in the fetal membranes (chorioamnionitis, chorioamniodeciduitis, choriodeciduitis) with extensive necrosis of the amniotic epithelium; in 74% of cases, this form of oligohydramnios develops against the background of infectious and inflammatory diseases of the mother and in 25% of cases is combined with placental insufficiency and the fetal growth retardation syndrome (FGR) that developed against their background;
- atrophic lesion of the decidua, which is characterized by a predominant lesion of the decidua with the relative preservation of the amniotic epithelium, compact layer and cytotrophoblast (CT); this form of oligohydramnios often develops against the background of maternal vascular pathology, as well as metabolic disorders, and is combined with placental insufficiency and sdfd in 46% of cases;
- dysontogenetic form of changes in the membranes, which is characterized by the absence of inflammatory changes in the presence of a significant number of atrophic villi in the CT layer; this form of oligohydramnios often develops against the background of infectious and inflammatory diseases suffered immediately before conception and in the first trimester of pregnancy, and is characterized by the most frequent combination of oligohydramnios with placental insufficiency (86%) and fetal malformations (54%).
Analysis of the course of pregnancy and childbirth in pregnant women with oligohydramnios, conducted by various authors, revealed a number of severe complications:
- number of threatened miscarriages and premature birth ranges from 36 to 48.8%;
- weakness of labor activity - a frequent complication of the course of childbirth with oligohydramnios (9.6%); the appearance of primary weakness of labor activity, some authors associate with the formation of a flat bladder in childbirth and a violation of the processes of retraction and distraction of the muscle fiber of the cervix;
- with oligohydramnios, bleeding is much more common due to residues in the uterine cavity of the membranes and placental tissue - in 4% of cases;
- an increase in the number of cases of bleeding during childbirth leads to an increase in such surgical interventions as manual and instrumental examination of the walls of the uterine cavity - in 12.6%;
- an increase in the number of cervical ruptures with a reduced amount of amniotic fluid - in 24% of women in labor.
Most authors note an increase in the number of cases of congenital anomalies in the development of the fetus (from 17 to 13%) during pregnancy complicated by oligohydramnios (R. Romero et al., 1994; N. Damato et al., 1993). Insufficient amount of amniotic fluid in the II trimester of pregnancy leads to the development of fetal lung hypoplasia. Severe oligohydramnios limits the motor activity of the fetus and is often complicated by joint contractures and anomalies of the facial skeleton. With pronounced oligohydramnios, adhesions are formed between the skin of the fetus and the amnion, which take on the character of strands or threads. Linking together separate parts of the placenta, umbilical cord and parts of the fetus, amniotic constrictions can lead to a variety of fetal anomalies (deformities or amputations of limbs or fingers).
Polyhydramnios- one of the forms of obstetric pathology associated with excessive accumulation of amniotic fluid in the amniotic cavity (more than 2 liters). This pathology occurs in 0.13 - 3% of cases. Emphasizing the attention of specialists in ultrasound diagnostics to this problem is due to the fact that echography is the most accurate method for diagnosing polyhydramnios and, under echographic control, the observation and treatment of pregnant women with this pathology is carried out.
Polyhydramnios can be acute and chronic. Acute polyhydramnios is extremely rare, and, as a rule, occurs at 16–27 weeks of gestation, more often observed in monozygotic twins, infectious diseases, especially viral ones. Chronic polyhydramnios is more common. It is usually first diagnosed in the third trimester of pregnancy and has a more blurred clinical picture. The number of cases of chronic polyhydramnios ranges from 0.17 to 2.8%.
Causes of polyhydramnios not fully disclosed. However, the pathological conditions of the pregnant woman and the fetus, in which polyhydramnios is observed, have already been quite clearly defined. The analysis of numerous literature data made it possible to identify the following possible causes of polyhydramnios:
- maternal reasons:
- isoimmunization;
- diabetes;
- infectious and inflammatory diseases;
Placental causes:
- chorionangioma;
- "placenta surrounded by a roller";
fruit reasons:
- multiple pregnancy;
- feto-fetal transfusion syndrome;
- congenital malformations of the fetus;
- chromosomal abnormalities and hereditary diseases;
idiopathic polyhydramnios ( ! the frequency of idiopathic polyhydramnios is the lower, the more extensive and thorough the examination was conducted in the antenatal period).
The most accurate diagnosis of polyhydramnios can be made during ultrasound. Polyhydramnios is characterized by the presence of large echo-negative spaces in the uterine cavity. In this case, as a rule, there is an increased motor activity of the fetus, its limbs, internal organs, and umbilical cord are better visualized. With moderate polyhydramnios, the size of the vertical "pocket" is 8 - 18 cm, with severe polyhydramnios this figure exceeds 18 cm. IAI with polyhydramnios is more than 24.
In 1984, P. Chamberlain et al.. The following ultrasonic options for the amount of amniotic fluid depending on the depth of their pocket were presented:
- water pocket depth<1,0 см - маловодие;
- 1 - 2 cm - reduced (boundary) amount of water;
- >2.0 cm but<8,0 см - нормальное количество вод;
- >8.0 cm - polyhydramnios.
- moderate - pocket depth 8.0 - 11.0 cm;
- average - 12 - 15 cm;
- heavy - 16 cm and more.
We do not remember what happened to us before birth, but, apparently, we were fine.
- First, heat: the temperature of the amniotic fluid is always kept at around 37 ° C.
- Secondly, it is quiet enough: the liquid absorbs shocks well and drowns out the noise coming from the outside world.
- Thirdly, due to the tightness of the bubble, nothing superfluous gets into it.
- Fourthly, in the amniotic fluid there are immunoglobulins that protect the little man well from possible troubles.
- Fifthly, the amniotic fluid can be compared to a kind of buffer that protects the baby from pressure from the outside world and makes sure that the main means of communication with the mother - the umbilical cord - is not pinched.
- Sixthly, the child is not deprived of freedom of movement (especially in the early stages) and swims in the amniotic fluid.
Experts note that during the first bath after birth (its purpose is to wash off the original lubricant), children relax perfectly, feeling themselves in their familiar environment. And this is very important before starting a completely new life in a completely different world - the world of fresh air.
Where does water come from and what is it made of?
When a fertilized egg attaches to the wall of the uterus and begins to divide, the components of a complex mechanism are formed: fetal membranes, placenta, umbilical cord and embryo (future baby).
The fetal membranes (amnion and chorion) form a sealed bubble with an absolutely sterile liquid inside. By the end of the second week of pregnancy, the bubble completely fills the uterus, and up to 14 weeks, the amniotic fluid seeps into the baby's body through the skin. Then his skin is enriched with keratin and becomes thicker, and from that moment on, water enters through other channels. For example, in the digestive tract: the baby absorbs liquid and removes it from the body along with urine. Over time, the volume of water processed by him reaches several liters per day, despite the fact that there is always about one liter of fluid in the uterus.
Where does it come from? Amniotic fluid is formed by sweating blood plasma from the mother's blood vessels. In late pregnancy, the kidneys and lungs of the baby begin to take part in the production of amniotic fluid. By the end of the term, its amount reaches 1-1.5 liters, and every three hours it is completely renewed, with one third being processed by the baby.
Almost 97% of the amniotic fluid is water, in which a variety of nutrients are dissolved: proteins, mineral salts (calcium, sodium, chlorine). In addition, it can detect skin cells, hair and aromatic substances - alkaloids. There is an opinion that the smell of amniotic fluid is similar to the aroma of mother's milk, which allows a newly born baby to accurately determine where the mother's breast is.
In the West, in some maternity hospitals, newborns do not wash their hands so that they can suck their fingers, "flavored" with amniotic fluid, to the smell of which they are so accustomed.
How are waters involved in the birth process?
Amniotic fluid is a living environment, thanks to being in which many vital functions begin to work in a child. The kidneys of the little one begin to work due to the fact that he swallows water, processes and excretes them together with urine (amniotic fluid is found in the baby's bladder already at the 9th week of pregnancy). Over time, the child, like a fish, begins to “inhale” the liquid, doing the first and very important exercise for the lungs, preparing them for breathing in a normal atmosphere. During childbirth, the lungs contract, the rest of the amniotic fluid comes out, and immediately after that, the baby takes his first breath.
At the end of pregnancy, the fetal bladder begins to put pressure on the cervix, which helps it open up. On the day of delivery, after the rupture of the membranes (regardless of whether this happens naturally or artificially), fluid enters the birth canal and washes them, which helps the baby move forward. If the baby lies head down, then at the beginning of childbirth, only those waters that are in front are poured out, while the rest protect him further, and come out only with the birth of the baby.
Water volume
Since everything related to the state of the amniotic fluid is very important for the health of the child, doctors carefully monitor everything that happens to them. Both polyhydramnios and oligohydramnios can negatively affect the development of the embryo.
Isolation of amniotic fluid before childbirth
According to statistics, every fifth woman loses some amount of amniotic fluid before the rupture of the fetal bladder. When the amniotic fluid begins to "leak", mothers get scared: it seems to them that they did not have time to run to the toilet (in order not to make a mistake with the conclusions, tighten your muscles: urine flow can be stopped by willpower, but amniotic fluid cannot).
Because leaking amniotic fluid can lead to an infection in your baby, it's in your best interest to see a doctor. He will take a smear from the cervix for elements of amniotic fluid, and then he will decide what to do next. If all this began before 34 weeks and the baby's lungs have not yet "ripened", doctors will prolong the pregnancy by protecting the baby with antibiotics. At this time, the expectant mother will be prescribed medications, with the help of which the baby's lungs will “ripen”, and the cervix will prepare for childbirth. If the leakage of amniotic fluid is accompanied by an infection (the expectant mother has a fever, there are a lot of leukocytes in the blood test and vaginal smear, and the erythrocyte sedimentation rate (ESR) accelerates), the woman immediately begins to prepare for childbirth.
The entire period of intrauterine development, the child spends in the fetal bladder filled with amniotic fluid or amniotic fluid.
Amniotic fluid, which has a complex chemical composition, is necessary for the normal life and development of the fetus, it protects the unborn child from infections and external influences, and ensures freedom of movement.
The composition and amount of amniotic fluid are constantly changing throughout pregnancy, the maximum volume of fluid inside the fetal bladder is reached by 32 weeks, then gradually decreases and by the end of pregnancy is about 1.5 liters.
To assess the amount of amniotic fluid, the amniotic fluid index is used, which is determined during an ultrasound examination by summing up the four values of the amniotic space on the monitor, the vertical size of the amniotic fluid, measured in mm, is displayed in black. To obtain these data, during the examination, the uterus is conditionally divided into 4 squares, the largest space in each of them is measured, then the obtained indicators are summarized.
Below is a table of the norm of the amount of amniotic fluid for different periods of pregnancy. If the amniotic fluid index goes beyond the upper limit of these norms, then, in accordance with the gestational age, the doctor speaks of polyhydramnios. If this index slightly exceeds the norm, then it is customary to talk about moderate polyhydramnios during pregnancy.
Table of norms of amniotic fluid at different stages of pregnancy
Pregnancy period, weeks | Average normal indicator, mm | Probable fluctuations, mm |
Amniotic fluid index at different stages of pregnancy
Gestational age, | Amniotic fluid index, mm |
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You need to focus on the middle column of the 50th percentile, the 2.5th shows the lower, and the 97.5th shows the upper limits of the norm. That is, if the vertical value of amniotic fluid is slightly higher than the 97.5 percentile, this indicates moderate polyhydramnios.
For the diagnosis of polyhydramnios, an ultrasound examination, doplerometry, examination by a doctor are carried out, and to confirm the diagnosis, it is carried out.
Causes
There are several reasons why moderate polyhydramnios develops. These include:
- - large fruit;
- - multiple pregnancy (two or more fetuses);
- - Rh-conflict of mother and fetus;
- - the presence of a woman with chronic diseases;
- - intrauterine infections;
- - various pathologies of fetal development (including genetic ones);
- - late toxicosis ()
- - placental disorders;
- - diabetes mellitus in a pregnant woman;
- - anatomical features of the structure of the uterus.
In general, the causes of moderate polyhydramnios have not been fully studied to date.
signs
Even before the examination and examination, a woman may suspect moderate polyhydramnios for the following signs:
- - swelling;
- - increased heart rate;
- - heaviness and pain in the abdomen;
- - the circumference of the abdomen along the navel increases sharply and reaches 100-120 cm;
- - weakness and general malaise;
- - shortness of breath, which is a consequence of the high standing of the fundus of the uterus and the pressure of the diaphragm on the lungs.
If you suspect the development of even moderate polyhydramnios, the pregnant woman should contact her doctor to establish an accurate diagnosis and conduct timely treatment, which can be either outpatient or inpatient. It necessarily includes the appointment of vitamin preparations, diuretics and antibiotics. The process is usually simple and treatment is prescribed after establishing the cause of the development of this pathology. And it is necessary to carry it out, since polyhydramnios can have serious consequences for the child:
- - rupture of membranes and premature birth;
- - cord entanglement (including multiple) and complicated childbirth (weak labor activity) and others.
But with timely and adequate treatment under the supervision of a doctor observing the pregnancy, moderate polyhydramnios is not so dangerous and does not carry the described consequences.