How long does it take for amniotic fluid to appear? Amniocentesis - analysis of amniotic fluid. Normal values, mm
Violation of the formation and absorption of amniotic fluid threatens with oligohydramnios. Let's consider this concept in more detail.
What is low water?
An insufficient amount of amniotic fluid in obstetrics and gynecology is called oligohydramnios.
amniotic fluid(or amniotic fluid)- the liquid environment in which the fetus is located during pregnancy.
This biological fluid performs several important functions. These include:
- protective function- the water shell protects the child from the penetration of infections (due to the tightness of the shells and the immunoglobulins that make up the water), from mechanical influences from the outside (for example, from shocks and shocks), loud sounds (water muffles them), external fluctuations in pressure and temperature (maintaining optimal pressure and a constant temperature of 37 ºС, of course, if the mother is healthy and her body temperature does not exceed 37.8 ºС);
- exchange function- the child absorbs the amniotic fluid, enriched nutrients, and allocates it back.
To all this, the fetal waters provide free movement of the crumbs inside the womb. Therefore, with a normal amount of amniotic fluid, the baby is cozy and comfortable, he is protected and provided with everything necessary.
What is in the amniotic fluid?
With an increase in the duration of pregnancy, the composition amniotic fluid changes, and becomes more varied and saturated, which makes the waters slightly cloudy in appearance. The amniotic fluid is secreted by cells of the aquatic membrane.
At the beginning of pregnancy, amniotic fluid is almost the same in composition as blood plasma. They contain nutrients (proteins and fats), vitamins and minerals, hormones, enzymes, and more.
From the second trimester, the composition of this biologically active fluid is supplemented by dead skin cells (as a result of the natural process of changing the old skin layer to a new one), the fluff (hairs) of the fetus, the original cheese-like lubricant of the fetal body and its waste products (sterile urine).
Fertile waters are updated every 3 hours.
Drinking water does not affect the amount of amniotic fluid. From excessive fluid intake in a pregnant woman, only edema will appear.
The norm of the amount of amniotic fluid
When the amount of amniotic fluid deviates from the norm, doctors diagnose oligohydramnios or polyhydramnios. The doctor-diagnostician determines the amount of fluid during an ultrasound scan, starting from the second trimester of pregnancy.
The volume of amniotic fluid in medicine is commonly referred to as the amniotic fluid index (AFI).
Table - The norm of the amniotic fluid index by week
The norms may differ slightly from those given above, depending on the type of ultrasound machine. And also the value can be written not in millimeters, but in centimeters (1 cm = 10 mm).
Also, the amount of fetal water characterizes another indicator - the vertical size of the largest (free) water pocket (VC). This size should normally be in the range of 2 to 8 cm (or 20 to 80 mm), with a borderline amount of water - from 2 to 1 cm (20 to 10 mm), and with oligohydramnios - less than 1 cm (or 10 mm).
What are the causes of oligohydramnios?
Depending on the severity of the pathology, moderate and pronounced oligohydramnios.
You can often find in the ultrasound protocol the inscription - “the tendency to moderate oligohydramnios". This means that it is possible that the expectant mother has health problems and needs more careful monitoring.
Moderate oligohydramnios- this is a slight deviation in the amount of fetal water from the norm. This type of deviation may be caused by the individual characteristics of the body of a pregnant woman or, in the worst case, may be a prerequisite for the occurrence of a more severe form of this pathology. In any case, doctors recommend prophylaxis of fetoplacental insufficiency (FPI).
Moderate oligohydramnios is not a critical situation, because the amount of water is a variable number, and can change several times a day. Perhaps there was an error in establishing the diagnosis and the fault of the doctor, who did not particularly exact calculation during ultrasound, because the determination of the amniotic fluid index is a subjective and approximate matter. Therefore, you should not panic, in 8 out of 10 cases, pregnancy ends with a successful birth of a healthy baby.
Severe oligohydramnios poses a danger to the health of the fetus, so you must follow all the instructions of the doctor observing the pregnancy.
The causes of oligohydramnios, regardless of the degree of its severity:
- feto placental insufficiency;
- problems with the cardiovascular system in a pregnant woman (hypertension and others);
- diseases of the urinary system of the fetus (kidneys, for example);
- leakage of amniotic fluid (in case of violation of the integrity membranes);
- pathology in the development of fetal membranes;
- transferred bacterial infections during pregnancy or shortly before its onset;
- diabetes;
- late gestosis.
Most often, oligohydramnios occurs due to a metabolic disorder in a pregnant woman, as well as after viral diseases (ARI, SARS, and others) and with fetoplacental insufficiency.
Personal practice shows that ultrasound doctors often exaggerate the magnitude of the problem, and a slight deviation from the norm is already a disaster for them. Such pseudo-low water causes extra stress at future mother, but in fact, babies are born relatively healthy.
The only thing is that childbirth with oligohydramnios (even slight ones) can take place with some complications (poor opening of the cervix, painful contractions and prolonged labor due to breech or breech presentation of the fetus, which arose due to oligohydramnios). Although complicated childbirth can occur in any woman in labor, regardless of the amount of water.
obstetrician-gynecologist A. Berezhnaya
The occurrence of oligohydramnios during a post-term pregnancy is considered a common occurrence, since the placenta has grown old and can no longer fully perform its functions, therefore it exfoliates. Then doctors prescribe stimulation labor activity or carry out a planned C-section.
Why is oligohydramnios dangerous for the fetus?
Oligohydramnios (or oligohydramnios) is a complication of pregnancy, sometimes even dangerous for the fetus, because it is at risk of infection, as a result of which even its death can occur.
For example, with the loss of the integrity of the membranes - this is when there is leakage of amniotic fluid - the child becomes vulnerable to infections entering the membranes.
The genital tract of a woman is not sterile, pathogenic microorganisms constantly live in the vagina, “plus” immunity is weakened due to pregnancy. All this can lead to the multiplication of harmful bacteria that can penetrate the uterine cavity and infect the fetal membranes, causing their inflammation, called chorioamnionitis in gynecology. Without timely treatment infection occurs in the fetus.
This is with regard to oligohydramnios, caused by a violation of the integrity of the membranes.
With severe oligohydramnios, regardless of the reasons for its occurrence, the baby suffers from hypoxia (lack of oxygen), because of this, it lags behind in intrauterine development. In addition to all this, the baby is uncomfortable to be in such a “nest”, his neck is often twisted, and the bones of the face and head are susceptible to deformation due to squeezing them by the walls of the uterus.
Moderate oligohydramnios does not have such a critical effect on the health of the fetus: the baby is weak and lags behind in weight gain (so-called malnutrition is observed), it muscle tone reduced (possible development of torticollis, clubfoot), there is also mild fetal hypoxia.
If the screening and urine / blood / smear tests are normal, the cardiotocogram (CTG) is in order and the fetus is developing well, and the pregnant woman has no complaints about her well-being, then the diagnosis of oligohydramnios is conditional. It’s just that obstetricians will prepare for labor induction, since there is a high probability of a post-term pregnancy, or for a caesarean section with a non-standard position of the fetus at the time of birth.
Diagnosis of oligohydramnios
At ultrasound examination the doctor makes some measurements and calculations to determine the amount of amniotic fluid, after which he makes a conclusion about oligohydramnios, a normal amount of water, or polyhydramnios.
A gynecologist can also suggest little or polyhydramnios at the next measurement of the circumference of the abdomen and the height of the fundus of the uterus, but a more accurate diagnosis can only be made with the help of ultrasound.
At home, you can only test for leakage of amniotic fluid. If on underwear often seen watery discharge, and the kicks of the baby began to be painfully perceived by the pregnant woman, although such discomfort was not felt before, or the size of the abdomen is small, although the gestational age has already exceeded 20 weeks, it is advisable to carry out special test. Perhaps the reason for everything is lack of water, caused by leakage of water due to a violation of the integrity of the membranes.
The test can be done at home by monitoring the discharge for some time, or by buying a special amniotic fluid leak test at the pharmacy and using it.
The "free" test is carried out as follows: empty bladder, take a shower (without douching and possible water getting inside the vagina), dry yourself with a towel and lie down on a dry diaper. Lie still for 15 minutes, and then get up and see if wet spot on a diaper. Ordinary secretions are not able to form and flow out so quickly, most likely, amniotic fluid is leaking. You can find out more precisely by contacting the LCD with a complaint about unusual discharge. There they will conduct a special test and say it is water or ordinary vaginal discharge.
The pharmacy test looks like a gasket, the surface of which will change color to blue or green if amniotic fluid leaks.
Staining also occurs with bacterial / viral discharge, so if spots of a blue-green hue are noticed on the surface of the pad, contact your gynecologist.
Any test for amniotic fluid leakage is recommended after 12 hours since the last intercourse, douching or use of vaginal suppositories.
Treatment of oligohydramnios
It is impossible to artificially increase the amount of amniotic fluid, so the treatment of oligohydramnios comes down to determining the causes of its occurrence. Further, the treatment of the root causes of oligohydramnios is carried out.
To determine the causes of oligohydramnios, a pregnant woman is referred for doppler ultrasound or cardiotocography (CTG), in order, first of all, to refute or confirm a violation of blood flow in the placenta.
If the fetoplacental circulation is still disturbed, then the patient is prescribed drugs to normalize it - Curantil, Actovegin.
Moreover, Curantyl is often prescribed as a preventive measure for placental insufficiency.
Often, the complex of treatment includes medications that contribute to the normalization metabolic processes in the body of a pregnant woman (for example, Magne + B6) and supporting the normal functioning of important internal organs women (for example, Hofitol).
It is also necessary to exclude the presence of infections in a pregnant woman. For this purpose, urogenital smears for STIs and from the throat + nose for cocci are re-taken, a blood test for TORCH infection is performed. If an infection is present, antibiotic therapy is prescribed.
Childbirth with oligohydramnios
With severe oligohydramnios, a planned caesarean section is prescribed. With a small amount of amniotic fluid amniotic sac acquires flat view. Because of this, contractions will be irregular and weak, and labor can be long and difficult.
Moderate oligohydramnios is not a contraindication for natural childbirth. Even with pelvic or breech presentation fetus caused by oligohydramnios, childbirth takes place safely for both the mother and her child.
Insufficient amount of amniotic fluid does not give the baby the opportunity to move freely inside the womb. Therefore, often the child takes a transverse or gluteal position and he can no longer roll over correctly.
There are various exercises that can help turn the crumbs into the desired position, but their effectiveness has not been confirmed with medical point vision. Exercise can lead to cord entanglement, so you need to weigh the pros and cons before doing them.
Pregnancy is considered the most the best period in the life of every woman. Waiting for the birth little miracle inspires happiness and fills life with bright colors. However, apart from positive emotions women also have others associated with fear and ignorance of many processes that occur in a pregnant woman in the body. What are the norms of the amniotic fluid index by week? This is one of the questions that women think about. Let's look into it, because according to the values \u200b\u200bof the indicator (abbreviated designation - IAI, JOB), the state of the fetus is determined.
The concept of amniotic fluid
The fetus develops in the uterus during pregnancy. It is surrounded by fetal membranes and fluid, which acts as a natural environment for the fetus. She protects him from mechanical damage, creates conditions for movement and proper location in the uterus. Each period of pregnancy is characterized by a certain amount of fluid. Taking it into account, experts make diagnoses about the presence of certain diseases in the fetus.
In the first trimester, the volume of water surrounding the embryo is determined by the function female body. Subsequently, the fetus begins to influence the amount of fluid. It is swallowed by them and excreted in the urine. When natural processes are disturbed, the volume of the liquid changes up or down. Normally, at the 18th week, this figure is 300 ml. By the 34th week, it increases to 800 ml. With the approach of childbirth, the volume of fluid decreases to 600 ml.
Calculation of the volume of amniotic fluid
There are several ways to find out the volume of amniotic fluid. The first one is subjective. A specialist during an ultrasound scan can identify deviations from the norm according to some signs and features:
- An insufficient amount of fluid is observed, as a rule, in the II and III trimester. In the uterine cavity, areas of amniotic fluid free from the umbilical cord are not detected. The body of the fetus is excessively bent. Parts of the body are close to each other.
- Excessive fluid is most often observed in the third trimester. The anatomical features of the fetus are very well distinguishable. Bottom part body is surrounded by fluid.
When using the subjective method, you can make a mistake. That is why J. Phelan proposed the calculation of the AFI. The conducted studies made it possible to determine the norms of the amniotic fluid index by weeks. When comparing them with the values obtained during examinations of pregnant women, one can judge the presence of a lack or excess of water.
Amniotic fluid index: what is it and how is it calculated
In order to determine whether the volume of amniotic fluid is normal, experts measure a special index. This is done during ultrasound examinations. The specialist does the following:
- scans the entire uterine cavity;
- the area under study is divided into 4 quadrants;
- in each quadrant visualizes the deepest pocket of amniotic fluid, free from the extremities of the fetus and umbilical cord;
- defines the maximum vertical depth of each pocket;
- the resulting values are summarized.
The index is measured in centimeters or millimeters. The value obtained by adding the vertical depths is an approximation. Despite this, it can accurately identify an excess (polyhydramnios) or a lack (oligohydramnios) of amniotic fluid.
Ultrasound examination in the first trimester of pregnancy
For the first time, a pregnant woman is sent for a planned ultrasound in the first trimester. For this period, the norms of the amniotic fluid index by week are not defined, because the fetus is very small. Scanning is performed for slightly different purposes:
- confirm pregnancy;
- clarify the deadline;
- clarify the location of the fetal egg;
- identify multiple pregnancy;
- exclude cystic skid;
- exclude false pregnancy if a woman has neoplasms in the pelvic area;
- timely diagnosis of tumors, which in the future could prevent normal course pregnancy and childbirth.
Index in the II trimester of pregnancy
The next ultrasound examination of a woman takes place in the second trimester of pregnancy, which lasts from the 14th to the 26th week. At this time, various fetometric parameters of the fetus are determined. The amniotic fluid index is also calculated. The norm at 20 weeks and at other times of the II trimester is presented in the table below.
| Term, in weeks | Indicator, in mm | ||||
| Percentile | |||||
| 97,5 | 95 | 50 | 5 | 2,5 | |
| 16-18 | 201-220 | 185-202 | 121-133 | 79-87 | 73-80 |
| 19-21 | 225-233 | 207-214 | 137-143 | 90-95 | 83-88 |
| 22-24 | 235-238 | 216-219 | 145-147 | 97-98 | 89-90 |
| 25-26 | 240-242 | 221-223 | 147 | 97 | 89 |
Ultrasound scanning in the third trimester of pregnancy
The last trimester of pregnancy lasts from the 27th week until the moment of delivery. During this period, every pregnant woman undergoes a final ultrasound scan. This trimester is optimal for:
- determining the amount of water;
- diagnosing fetal growth retardation;
- detection of fetal pathologies not detected during previous scans;
- determining the position of the fetus and identifying placenta previa;
- exclusion of any pathologies that can occur during pregnancy.
The table below shows the norms of the amniotic fluid index by week for last trimester childbearing period.
| Term, in weeks | Indicator, in mm | ||||
| Percentile | |||||
| 97,5 | 95 | 50 | 5 | 2,5 | |
| 27-29 | 245-254 | 226-231 | Decreased from 156 to 145 | From 95 to 92 | From 85 to 84 |
| 30-32 | 258-269 | 234-242 | From 145 to 144 | From 90 to 86 | From 82 to 77 |
| 33-35 | 274-279 | 245-249 | From 143 to 140 | From 83 to 79 | From 74 to 70 |
| 36-38 | from 279 to 269 | from 249 to 239 | From 138 to 132 | From 77 to 73 | From 68 to 65 |
| 39-40 | from 255 to 240 | from 226 to 214 | from 127 to 123 | from 72 to 71 | from 64 to 63 |
Polyhydramnios during pregnancy
Polyhydramnios in the medical literature is called excessive accumulation of amniotic fluid. At full-term pregnancy, their volume exceeds 1500 ml. In foreign sources, a figure equal to 2 liters is noted. According to the index, polyhydramnios is determined very easily. This pathology is characterized by an increase in the numerical values of the indicator by more than 97.5 percentile. For example, the rate of the amniotic fluid index at 32 weeks can reach a maximum of 269 mm. For cases in which the IAF is greater than this figure, an excess of water is characteristic.
Polyhydramnios is divided by experts into acute and chronic. First form pathological condition diagnosed at 16-27 weeks. It is considered extremely rare. The most common form of chronic polyhydramnios. It is detected in women, usually in the third trimester of pregnancy. The chronic form is characterized by an erased clinical picture.
The amniotic fluid index exceeds the norm at 30 weeks and at other times according to different reasons. They are associated with inflammation and infectious diseases pregnant woman, fetal pathologies (for example, intrauterine infections, hereditary diseases, chromosome abnormalities, developmental disorders digestive system, central nervous system), pathologies of the placenta.
oligohydramnios in pregnant women
In medicine, oligohydramnios is considered to be a reduction in the volume of water to 500 ml or less during a full-term pregnancy. In foreign sources, the figure characterizing this pathology is indicated - 300 ml. The diagnosis of "oligohydramnios" is made by doctors in cases where the IAI values are below the 5th percentile. For example, 80 mm is the amniotic fluid index at 26 weeks. It doesn't fit the norm. This is pronounced malnutrition.
Causes of oligohydramnios are associated with birth defects development of the fetus, due to which urine is not excreted in normal quantities from the body. Such pathologies include renal agenesis, bilateral multicystic renal dysplasia. In some cases, the causes of low IAI and oligohydramnios are fetal growth retardation, chromosome abnormalities, intrauterine infections, chronic renal and cardiovascular diseases in women, gestosis, placental insufficiency, post-term pregnancy, antenatal fetal death.
Importance of Index Calculation
IAG - important indicator. For example, comparing the calculated amniotic fluid index at 33 weeks with the norm does not just allow you to fix the presence of oligohydramnios or polyhydramnios. Thanks to the calculation of the indicator, it is possible to prevent the development of complications. Due to polyhydramnios, for example, there may be:
- incorrect presentation of the fetus;
- premature detachment of a normally located placenta;
- postpartum and prenatal bleeding;
- prolapse of the umbilical cord.
Oligohydramnios also has complications. It leads to intrauterine retention development of the fetus, the appearance of adhesions, increased risk of perinatal death. In children born to women diagnosed with oligohydramnios, underdevelopment of the skeleton and lungs, low body weight are often observed.
After comparing with the norm of the amniotic fluid index at 31 weeks and at other times, after identifying oligohydramnios or polyhydramnios, doctors prescribe the appropriate treatment, determine the tactics of pregnancy and childbirth. In some cases, termination of pregnancy is required. The indications for it are a combination of polyhydramnios or oligohydramnios with intrauterine malformations and acute form polyhydramnios that arose before
The child in the mother's womb is in the amniotic fluid - this is the amniotic fluid that surrounds the embryo and is necessary for the normal existence of the baby during intrauterine period. Amniotic fluid performs protective and exchange function. Water absorbs noise and absorbs shocks, protects the fetus from infections, and maintains a comfortable temperature.
The metabolic function is to nourish the embryo: it swallows the amniotic fluid along with the nutrients it contains and then excretes it back. With a sufficient amount of amniotic fluid, the embryo is reliably protected and provided optimal conditions for development.
What is the IAI indicator, why is it needed?
Where does amniotic fluid come from and what does it consist of? In terms of composition and properties, intrauterine fluids at the beginning of the gestational period are similar to plasma: they contain vitamins, hormones and enzymes. In the second trimester, dead skin cells, embryonic lubrication, baby hairs and waste products appear in the waters. The amniotic fluid is renewed every few hours. In this case, the amount of water should correspond to a certain norm, depending on the duration of pregnancy. With a small amount of water, there is a risk of infection and even death of the fetus.
To determine the rate of amniotic fluid, the IAI indicator is used - the amniotic fluid index. It allows you to control whether the amount of amniotic fluid in a woman in labor is normal or whether the embryo suffers from oligohydramnios or polyhydramnios. How much intrauterine fluid a pregnant woman has is determined by ultrasound.
Methods for diagnosing the amniotic fluid index
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subjective way
The amniotic fluid index is determined using ultrasound. That is why it is important to pass all the required ultrasound examinations on time: a planned ultrasound allows you to diagnose the lack of amniotic fluid in time and take necessary measures to prevent fetal pathologies. The specialist will examine the uterus in different planes and visually determine the volume of fluid, visually assess the thickness of the water layer between the embryo and the abdominal wall and draw a conclusion about oligohydramnios or polyhydramnios. This diagnostic method is not accurate, so you should not rely on it.
objective way
Determination of the volume of amniotic fluid in an objective way ultrasound is carried out by dividing the uterine cavity into 4 equal segments. The abdomen is divided into squares, the marking axis is drawn through the middle vertically and through the navel horizontally. In each square, a space free from the fetus is selected, and the maximum distance from the child to the wall is measured. The four indicators obtained (the depth of the “pocket” in each square) are summarized and the total value of the amniotic fluid index is found.
IAI norms depending on the week of pregnancy
Amniotic fluid index norms change throughout pregnancy. At what time is the IAI maximum? For the first 27 weeks, the index gradually increases, and then by 30-32 weeks of gestation it begins to decrease. Average at 36 weeks it is 13.8 cm. By week 40, the indicator reaches its minimum value.
The IAI norms for each woman are different and may be slightly less or more than the average, which is acceptable. Amount of amniotic fluid (in centimeters) per different terms shown in the following table.
| Number of weeks | Average, cm | Possible fluctuation range, cm |
| 16 | 12,2 | 7,20-20,2 |
| 18 | 13,4 | 8,1-22,1 |
| 20 | 14,2 | 8,7-23,1 |
| 22 | 14,5 | 9-24,1 |
| 24 | 14,8 | 9,1-24,3 |
| 27 | 15,6 | 9-24,5 |
| 30 | 14,5 | 8,3-25 |
| 32 | 14,5 | 8,0-26,8 |
| 33 | 14,4 | 7,4-27,5 |
| 34 | 14,3 | 7,3-27,4 |
| 35 | 14 | 6,9-27,2 |
| 36 | 13,8 | 6,8-27,1 |
| 40 | 12,1 | 6,4-24,5 |
Reasons for possible deviations
The volume of amniotic fluid may deviate in the direction of increase or decrease. Excessive accumulation of amniotic fluid (polyhydramnios) is not as common as oligohydramnios. An excess of fluid leads to breech presentation, contributes to premature birth, as well as fetal hypoxia and, accordingly, pathologies of its development. Causes of polyhydramnios: intrauterine infection, conflict between the Rh factors of a woman and a baby, diabetes mellitus, immune diseases, severe metabolic disorders in the mother's body.
Polyhydramnios during full-term pregnancy is considered a state when the volume of water exceeds 2000 ml. Polyhydramnios occurs in the second half of gestation and is clearly diagnosed at 34-35 weeks. In this case, the IAI indicator can exceed the average value by 2 times. The volume of water in some cases is more than four liters. It is necessary to carry out treatment aimed at regulating the placental-uterine circulation.
When there is a shortage amniotic fluid malnutrition develops. Causes of a small amount of amniotic fluid in pregnant women:
- depressurization of the membrane of the fetal bladder and fluid leakage;
- defects of the fetal membrane;
- pathology of the kidneys in the baby and blockage of the ureters of the embryo;
- kidney disease or of cardio-vascular system in a woman;
- late toxicosis (starting from 33 weeks);
- circulatory disorders in the placenta (fetoplacental insufficiency).
Oligohydramnios can be moderate and severe. moderate degree implies a slight deviation of the volume of intrauterine fluid from the allowable values. This does not represent great danger: water renewal occurs regularly, their number varies and depends on individual characteristics women. Severe oligohydramnios is observed, most often, at the end of pregnancy.
The amniotic fluid index can reach values that are half the average. This degree of pathology poses a threat to the baby and can cause complications during childbirth.
Concomitant symptoms of pathological abnormalities in the volume of amniotic fluid
With polyhydramnios, a pregnant woman experiences shortness of breath and tachycardia attacks. Legs and face are very swollen. The woman gains a lot of weight and may complain about drawing pains in the groin The abdomen becomes very large and covered with stretch marks. General state of health - lethargic, weak; disturbed night sleep.
With severe oligohydramnios, the abdomen is small, the bottom of the uterus drops. Fetal movements are weak, hardly perceptible. The child suffers from oxygen starvation and underweight. In rare cases, drying out is possible. skin baby and its fusion with the fetal membrane. Most often, the fetus is in the breech presentation. If oligohydramnios is caused by leakage, the woman will notice colorless discharge from the vagina.
When examining vaginal discharge (amniotest), placental protein is detected - a sure symptom of amniotic fluid leakage. Childbirth with a meager amount of water proceeds with complications: the cervix opens slowly, contractions are painful, labor is long. In case of full-term pregnancy and damage to the membranes, when there is leakage of water, the issue of inducing labor and artificial activation of labor is decided.
IAI does not correspond to the norm: what to do?
If a deviation of the IAI from the permissible values is detected, it is necessary to carry out comprehensive examination future mother in order to identify and eliminate the causes of pathology. In cases where amniotic fluid is formed in excess quantities, it is important to normalize proper nutrition women and adjust her drinking regimen. A woman in labor will be prescribed a course of vitamins (C, E, B), preparations containing magnesium, and diuretics. In the presence of intrauterine infection shown a course of antibiotic therapy.
Moderate oligohydramnios during gestation suggests a slight change in the volume of water. In this situation, it is enough for a woman in labor to adjust her diet and daily routine - in most cases, the AFI will increase to acceptable limits without harming the health of the fetus. A woman with severe oligohydramnios must be placed in a hospital to prevent complications in the baby. They carry out therapy for placental insufficiency and try to keep the fetus as long as possible so that it becomes ready for birth. When pregnancy is more than 33 weeks, a decision is made to stimulate labor.
Amniotic fluid (amniotic fluid) is the biologically active fluid that surrounds the fetus during pregnancy. It consists of water and contains small amounts of mineral salts, fetal cells, fragments sebaceous glands and flakes of the epidermis. The formation of amniotic fluid begins in the third week of pregnancy and reaches 1-1.5 liters by the time of delivery.
Amniotic fluid not only allows the baby to move freely in the womb, but also maintains a constant body temperature and protects against infection and mechanical influences from the external environment. By the end of pregnancy, the kidneys and lungs of the unborn child begin to take part in the production of amniotic fluid.
Amniotic Fluid Analysis
Diagnosis of amniotic fluid is divided into invasive and non-invasive. The second group includes one method - ultrasound. During an ultrasound examination, the doctor can determine the amount and index of amniotic fluid (AFI).Invasive diagnosis of amniotic fluid includes:
Amnioscopy. During amnioscopy, a tube with a flashlight (amnioscope) is inserted into the cervix. When illuminating the amniotic fluid, you can see their color and consistency, as well as the presence of blood or feces in them. Amnioscopy is performed after 37 full weeks pregnancy.
Amniocentesis. Amniocentesis is the removal of amniotic fluid by puncturing the amniotic membranes. The puncture is carried out through abdominal cavity or through the vaginal wall or cervix. With amniocentesis, it is possible to determine the composition of amniotic fluid and thereby identify pathology in the unborn child. It is carried out according to indications after 16 weeks. After taking amniotic fluid, bacteriological, histological, cytogenetic, biochemical analyzes are carried out.
Amniotic fluid index and its norm
Amniotic Fluid Index (AFI) is an indicator of the amount of amniotic fluid per specific date pregnancy. The study helps to establish a decrease and increase in the amount of amniotic fluid.The change in IAI has a certain pattern. From the beginning of pregnancy to 27 weeks of gestational age amniotic index gradually increases and averages 156 mm, then it goes down. The amniotic fluid index is not reduced compared to 27 weeks by about 10 mm.
The amniotic fluid index at 37 weeks, which is very close to childbirth, decreases by another 10 mm. Immediately before the baby is born (38-40 weeks of gestational age), there is a final decrease in the amniotic fluid index to an average of 125 mm.
Attention! The planned passage of ultrasound and the determination of IAI help to diagnose deviations in the amount of amniotic fluid in time and prescribe effective treatment to warn various pathologies in an unborn child.
The amniotic index is determined using ultrasound in two ways: subjective and objective. The first method is based on the fact that during ultrasound examination, the doctor scans the uterus in all planes and visually notes the volume of amniotic fluid. With a large accumulation of amniotic fluid between the fetus and the abdominal wall, the diagnosis of "polyhydramnios" is assumed, with a small one - "oligohydramnios".
Objectively, the amniotic fluid index is determined by dividing the uterus into 4 squares, the vertical marking axis passes through the center of the abdomen, the horizontal one through the navel. In each quarter, the maximum pocket is determined - the space where amniotic fluid is located without a child. Further, these indicators are summarized and the amniotic index is displayed - the result of adding the obtained values.
Norms of the amniotic fluid index by week in the form of a table
oligohydramnios during pregnancy
Oligohydramnios is a pathology in which the IAI is less than the lower normal value. The reasons may be:- renal pathology of the fetus;
- somatic diseases in a pregnant woman (chronic heart failure, chronic obstructive pulmonary disease, etc.);
- urogenital infections;
- smoking and alcoholism;
- placental diseases;
- carrying twins;
- aging of the placenta during re-carrying.
When fetal oligohydramnios is severe, or there are deviations in CTG, symptomatic therapy is used:
- Vitamins.
- Drugs that improve the blood supply to the placenta (Kurantil, Actovegin).
- Antibiotics.
Polyhydramnios during pregnancy
Polyhydramnios is a pathology in which the IAI is greater than the upper normal value. The reasons may be:- somatic diseases of the expectant mother (diabetes mellitus);
- infection during pregnancy;
- Rhesus conflict;
- congenital anomalies;
- increase in the weight of the unborn child.
In the process of treatment, constant monitoring of the fetal condition with the help of CTG is necessary, since with this pathology there is a possibility that the unborn child will become entangled in the umbilical cord. In case of ineffectiveness of conservative therapy, amniocentesis is used - taking no a large number amniotic fluid, or premature delivery.
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 essential role for 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 excretory system mothers, thereby cleansing the body of the child;
- 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
IN normal, amniotic waters have no color, odor, they are colorless, transparent, sometimes (normal variant) can be a little whitish. Also normal the presence of a small amount of white flakes is considered. 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 considered:
- unpleasant smell of waters and their green color. The green "colour" indicates oxygen starvation 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 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, these indicators can be used to diagnose various genetic pathologies. 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 hypoxia fetus.
Contraindications for 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 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, pathologies
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.
