The fetal development process takes place inside a special fluid, which serves as a whole world for a growing organism. Therefore, it is imperative that the condition and amount of water be within normal limits. A pregnant woman can affect this, observing the doctor’s instructions, as well as if she prepared in advance for her. Even if we exclude the risk of infectious and exacerbation of chronic diseases, then most complications can be avoided.
What is IAI?
One of the important indicators that is monitored during an ultrasound scan is the amniotic fluid index. This is a special fluid that fills the entire space inside the placenta, is produced by the amniotic membrane and serves as a favorable environment for the development and protection of the fetus from external factors.
In everyday life, a more familiar name is found - amniotic fluid, which is involved in the formation of the child's immunity. The quantity and quality of water can tell about how the development process occurs, whether there are any deviations or diseases.
From the beginning of development to 24 weeks, the fetal skin absorbs some of the amniotic fluid, thereby participating in metabolic processes. Starting from the 25th week, the skin becomes denser, which is an obstacle to the penetration of amniotic fluid. The index and indicators regarding the amount of amniotic fluid begin to track from the second trimester of pregnancy.
What are amniotic fluid?
Depending on the duration of pregnancy, the composition of the amniotic fluid undergoes changes. For the first trimester of pregnancy, it is close in composition to the plasma of the mother, in color - transparent in a small amount. At this stage, the mother’s body saturates the growing embryo with nutrients, proteins, vitamins, carbohydrates, lipids, hormones, oxygen, etc.
The second trimester is due to the rapid growth of the fetus. The color and composition of the waters are also changing. They can acquire a yellowish tint, since the bladder is already actively secrete the vital products of the growing fetal organism. In the third trimester, water may contain secretion products of sebaceous glands, cannon hair, and epithelial cells. It is noteworthy that the amniotic fluid is updated every three hours.
Methods for determining the level of amniotic fluid
In order to determine whether the amniotic fluid index corresponds to the weeks of pregnancy, there is a certain table with which doctors consult. One of the easiest ways to determine the composition, the presence of suspensions and the amount of water is an ultrasound scan. The specialist determines the total volume of amniotic fluid based on the size of the so-called pockets (areas free of amniotic fluid). These indicators are indicative and have a margin of error. Since the exact sensors for determining the amount of liquid have not yet been invented, in conclusion, you can see the value "+/-".
Closer to the date of childbirth can conduct an amnioscopy. The procedure consists in examining the lower part of the fetal bladder using a special device. Allows you to determine the color of amniotic fluid.
The most radical way to diagnose the composition and index of amniotic fluid is amniocentesis. It consists in piercing the fetal bladder and taking a sample of amniotic fluid. The need for this procedure is due to the identification of genetic abnormalities in the development of the fetus. It also allows you to determine biochemical, cytological, immunological indicators, how close they are to normal.
Amniotic fluid norms in pregnant women by week
At the beginning of pregnancy, the amniotic fluid index is negligible. According to the norms, by the end of the first trimester it is only 60 ml. Since the intensity of growth and development of the fetus falls on the second trimester, the water content in this period increases at the same rate. From the 13th to the 16th week of pregnancy, approximately 25 ml per week is added. At the time of the second screening (17-19 weeks), the volume of amniotic fluid reaches about 500 ml.
In the third trimester, the water consists mainly of urine produced by the fetus, which is released up to 450 ml per day. The norm of the amniotic fluid index by 38-1 weeks of pregnancy is about 1-1.5 liters. This value may change if there are pathologies or abnormalities in the development of the fetus.
Low water
If during an ultrasound examination during the second screening it is established that there is a deviation in the norm of the amniotic fluid index (less than 500 ml), then this may indicate a lack of water. Also, indicators are measured by the size of the pocket (in cm) and are checked with a special table.
The reason for the development of oligohydramnios may be an infection that develops in the fetus, or there is a pathology (for example, lack of kidneys or malformations of their development). Due to hypoxia, urine output into the amniotic fluid may decrease, which also leads to a small amount of amniotic fluid.
The presence of chronic diseases in a pregnant woman can lead to oligohydramnios, for example:
- Diabetes.
- Diseases of the cardiovascular system.
- Past viral diseases, bacterial infections.
Fetoplacental insufficiency, late gestosis, and deviations in the development of the membranes can also affect oligohydramnios.
In the second trimester, the norm of the amniotic fluid index in cm is from 12 to 14.5. depending on the week of pregnancy, they may differ slightly, but no more than by one. In the third trimester, the numbers decrease slightly, which is explained by the growth of the child, from 14.5 to 11 cm. Therefore, deviation from these norms in a smaller direction serves as an occasion for the diagnosis of oligohydramnios.
What threatens with low water?
It is customary to distinguish primary and secondary oligohydramnios. If in the first case the membranes remain intact, then in the second there is leakage of amniotic fluid. If it is insignificant, then the pregnant woman may not pay attention and take them for natural discharge. However, you can use the rapid test, which determines the leakage of amniotic fluid.
An insufficient amount of amniotic fluid leads to a developmental delay and occurs in 40% of pregnant women who are diagnosed with oligohydramnios. If up to 28 weeks the amniotic fluid index deviates significantly from the norm, the cause is identified, an examination is carried out. In the worst case, in the presence of malformations and genetic abnormalities, the question of abortion may arise.
Before childbirth and during the process itself, oligohydramnios can serve as an obstacle to the normal opening of the cervix. Since the child is cramped and there is not enough fluid that allows him to maintain motor activity, the likelihood of pelvic presentation becomes higher.
Low water treatment
It is possible to cope with oligohydramnios if the cause of the onset is diagnosed in time. In most cases, bed rest, a special diet, a vitamin course and medications are prescribed that will help stimulate the blood supply to the placenta and the fetus.
In order to monitor the state of health of the mother and child, additional dopplerography and ultrasound will be prescribed. In the presence of positive dynamics, it will be possible to return to the usual lifestyle and expect the date of birth.
Starting at 32 weeks (the amniotic fluid index is underestimated), if therapy is not possible, a cesarean section can be performed.
Polyhydramnios
About 1% of women experience polyhydramnios during pregnancy. The likelihood of developing this pathology may be due to:
- Multiple pregnancy.
- Chromosomal abnormalities and abnormalities in the fetus.
- Infectious diseases (including TORCH and genitourinary problems).
- Diabetes mellitus at any stage.
- Anemia, severe toxicosis.
- Kidney disease.
When calculating the norms of the amniotic fluid index by weeks of pregnancy, doctors take average values into account and always leave the probability of deviations up or down. However, if the diagnosis is confirmed, as a rule, after additional ultrasound studies and other tests, then you should be wary.
Polyhydramnios can develop very quickly (acute stage), and then it is important to decide on the preservation of pregnancy as soon as possible. there is a high risk of fetal death. If polyhydramnios develops gradually, then it is customary to call it chronic. In this case, doctors can resist the deterioration of the course of pregnancy.
The obvious signs that should alert the woman:
- An increase in the volume of the abdomen (more than 120 cm in girth).
- Swelling in the legs.
- Pain in the lower abdomen.
- Cardiopalmus.
- The size of the uterus is larger than the pregnancy term.
- Shortness of breath, weakness, constipation.
Pathologies of fetal development with polyhydramnios
If you disregard the disturbing symptoms, you can greatly harm yourself and your child. Therefore, doctors verify the data with the table of norms, which indicates the necessary correspondence of the amniotic fluid index by weeks in cm (centimeters). Among the critical deviations in the development of pregnancy can be observed:
- Preterm birth, which is very dangerous for less than 32 weeks.
- Placental abruption and heavy bleeding.
- Lack of labor or its weak course.
- Fetoplacental insufficiency.
For a child, an abundance of amniotic fluid can cause active movement and the risk of cord entangling. If the entanglement is tight, then the child may suffer from hypoxia. With polyhydramnios, the risk of infection and the development of defects in the central nervous system and heart is much higher.
Treatment regimen
After conducting research and passing tests, the doctor may advise you to take a course of vitamins, for example, containing magnesium, vitamins of groups B, C, E. If the cause is an infection, then diuretic, antibacterial drugs are prescribed.
During childbirth, the process of puncturing the bubble is carried out very carefully so that the effluent does not flow rapidly. After the end of labor, women in labor are prescribed drugs that stimulate the contractile function of the uterus.
Amniotic fluid color
With the help of ultrasound, you can understand whether the amniotic fluid index is normal. The 31st week is a time when the color of amniotic fluid is also of great importance, this indicator is given special attention. So, if the water is yellow, then this may indicate a Rhesus conflict. In the third trimester, for example, closer to the date of birth, about the content in the fluid of the vital products of the fetus. Red bleeding of amniotic fluid indicates internal bleeding.
If the water turns green, then this may be due to the release of meconium, the original feces. The ingress of its particles into the body of a child can lead to intoxication. This occurs in women who delay pregnancy.
Transparent waters are a sign of a normal pregnancy. A slight turbidity and the presence of suspensions of natural origin are allowed.