Norms of the amniotic fluid index by week
The official medical name for amniotic fluid is amniotic fluid. It is a liquid biologically active medium that is in the membranes and embryos.
Functions of amniotic fluid
Amniotic fluid is one of the factors ensuring the vital activity of the baby in the womb. This biological environment is characterized by several functions:
- Providing nutrition to the fetus. This fluid consists of a variety of nutrients. In the first period after fertilization, they are absorbed through the baby's skin, and a little later - the baby swallows a certain number of them.
- Maintaining adequate pressure and temperature conditions within 37 ° C.
- Providing the developing child with protection from external mechanical influences. The amniotic fluid significantly reduces the pressure and tremors that come from the external environment.
- Support for sterility, which is to protect the child from a variety of infections. In the amniotic fluid is a lot of immunoglobulins. In addition, the absolute integrity of the fetal bladder plays an important role. Sterility is provided by the constant renewal of amniotic fluid, which ends only after the birth of a child.
- Providing free movement of the baby in the uterus.
- Muting of strong external noise.
The main parameters of the amniotic fluid
During the entire period of pregnancy the composition and number of amniotic fluid are very important. There are many cases when deviations from the norm indicate the formation and development of various pathologies. Thus, it is possible to carry out diagnostics in time and eliminate them or to prepare appropriately for carrying out the necessary measures after the birth of the baby.
The amniotic fluid index (IOL) is a number that indicates its volume in the amniotic fluid.
When conducting diagnostics by a specialist, the following indicators are taken into account:
- Shade and transparency. The usual color of the liquid is light, transparent, with a small amount of impurities.
- Volume. The amount of fluid is affected by the gestational age. Therefore, the norm of amniotic fluid depends on the trimester of pregnancy. For example, the index of amniotic fluid at 21 weeks (norm) is 88-143-233 ml, where the first indicator is the lower norm, and the second is the average, the third is the upper limit. Daily increase in the amount of fluid by 40-45 ml continues until 32 weeks of pregnancy. After the index of amniotic fluid in 32 weeks (the average rate of 144 ml) reached its peak - the amount of water gradually decreases. On the eve of delivery it is only 500-1500 ml.
- Hormonal content.
- Biochemical and cytological compositions.
Indicators of amniotic fluid
The most informative criterion of lack of water in our time is ultrasound. In carrying out this study, the physician determines the IAP and the multiplicity of the vertical pocket. If these indicators do not reach the limits of the norm for a given period of pregnancy, then in conclusion a lack of water is indicated.
Vertical pocket is the name of the longest section of free amniotic fluid that is located between the fetus and the anterior abdominal wall. In addition, the location of free fluid in the umbilical cord or the extremities of the child is not allowed. The norm of the length of the vertical pocket is 5-8 cm, a little earlier with the help of ultrasound, only this indicator was established.
Rates of amniotic fluid index
Now, the amount of amniotic fluid is estimated with the help of an IWA. To do this, the doctor mentally divides the abdomen into 4 parts using 2 perpendicular lines intersecting in the navel area. Then, in each of these zones, the maximum vertical pocket is measured. In order to obtain the final value of the amniotic fluid index, it is necessary to add up all the obtained indices.
The norms of the amniotic fluid index are calculated for weeks of pregnancy, starting from the 16th week. Their value is gradually increasing. The highest index of amniotic fluid in 32 weeks is the norm from 77 to 169 ml. Then follows the decrease in the IOL.
IJA norm table
The norms of the amniotic fluid index are shown in the table by week.
The ILA standard table
Row of pregnancy (weeks)
If these indicators do not correspond to the specific pregnancy lines, there are polyhydramnios or hypochlorism.
Malignancy in pregnancy
It is a very unpleasant and very frequent phenomenon during pregnancy. If the deviation of the amount of amniotic fluid from the norm of the amniotic fluid index is insignificant by weeks - they diagnose "moderate water scarcity". In order to adjust it, you can use a diet, proper nutrition and a healthy lifestyle. After a while, the amount of water returns to normal and does not affect the baby's condition in any way.
The diagnosis of "marked malnutrition" is put in the case when the deviation from the norm of the index of the amniotic fluid is large for weeks on a smaller scale. With this diagnosis, you need urgent hospitalization and in-patient treatment. This is due to the high probability of the occurrence of deplorable consequences for the child.
If the index of amniotic fluid at 20 weeks (normal) is in the range of 86-230 ml, and ultrasound results indicate a much smaller real volume of amniotic fluid, in the absence of treatment it can provoke underdevelopment of vital organs, deformation of the skeleton bone, development of various pathologies of the fetus. Therefore, it is very important to start treatment of pronounced low blood pressure in time.
When the low index of amniotic fluid was determined at 34 weeks (the norm is an average of 142 ml), in addition, there are already pronounced deviations in the development of the child - often there is the question of abortion, since the treatment in this case is meaningless and will not bring any results.
Causes of development of aridity
There are many reasons for the formation of low salinity. The main ones are:
- underdevelopment of membranes or decreased secretion of water;
- abnormal development of the fetus (its kidneys, skeleton);
- increased arterial pressure in a future mother, especially if there are significant abnormalities;
- bacterial infections that penetrate not only through sexual pathways, but also directly into the amniotic fluid;
- multiple pregnancy, with uneven development of the placenta, giving a different blood flow to each fetus;
- the disturbed metabolism in the body of a woman, especially in the presence of excess weight.
Features of treatment
Even mild infertility can not be treated independently. Only on the basis of preliminary tests the doctor can evaluate the cause of the anomaly, the severity of the disease, the condition of the fetus and prescribe a course of treatment.
If there is obesity, impaired metabolism, you will have to follow a diet, eat right, take vitamins and medicines, which improves the blood supply of the placenta. Therapy of moderate polyhydramnios can be performed on an outpatient basis. A pronounced stage is treated only in a hospital. Regardless of the form of the disease, there is a need to limit the motor activity and the amount of physical activity, observance of bed rest.
During treatment, it will be necessary to do ultrasound and dopplerography more often than usual to determine the changes in the pregnant and the baby's organism in a timely manner.
If the ultrasound results showed a low amniotic fluid index at 33 weeks (normal - 143 ml) or later, when the baby is ready to be born, - the doctor can prescribe an early delivery.
If you find this fact, you do not need to get depressed. Still can be corrected - moderate stages are curable. In the presence of malnutrition during previous pregnancies it is necessary to inform the doctor about this. In this case, he will be able to detect and eliminate this problem in a timely manner.