Oligohydramnios during pregnancy: causes and consequences

Amniotic fluid plays a big role in the development of the baby - it is his first natural habitat. They also serve as a source of nutrients for the baby. Amniotic fluid protects the baby and affects its development. During the entire pregnancy, the volume of amniotic fluid should be a certain value. If their number falls below normal, we can talk about oligohydramnios.

Oligohydramnios during pregnancy: causes

As the number of weeks of pregnancy increases, the volume of amniotic fluid in the uterus also increases. On average, this amount is approximately 1.5 liters. This is enough to ensure the baby's normal development and free movement. As the due date approaches, the volume of amniotic fluid may decrease slightly; the same phenomenon can be observed in the case of post-term pregnancy.

Sometimes the amount of amniotic fluid may be less than normal. In this case, it is customary to talk about oligohydramnios. Oligohydramnios is classified according to several criteria:

• Chronic oligohydramnios is characterized by the fact that it can only be determined using ultrasound. In this case, the woman feels relatively well.
• Acute oligohydramnios is diagnosed by external signs - the abdomen and uterus are reduced, the woman feels pain when the fetus moves, weakness appears and nausea, pain in the lower abdomen.
• Previously, oligohydramnios develops around the 20th week of pregnancy for reasons of functional insufficiency.
• Late oligohydramnios may occur after 26 weeks due to the presence of other diseases.
• Primary oligohydramnios is characterized by preservation of the integrity of the fetal sac.
• With secondary oligohydramnios, the fetal sac ruptures and the amniotic fluid gradually leaks out.

There are enough reasons for the development of oligohydramnios. But most often the occurrence of this disease is associated with the following factors:

• The epithelium that protects the amniotic fluid membrane is damaged.
• Pathologies and abnormalities of child development, most often hereditary.
• Post-term pregnancy.
• Presence of bacterial infections in a woman's body.
• Hypertension.
• Problems with metabolism and excess weight.
• Multiple pregnancy.

The main cause of oligohydramnios has not yet been fully elucidated.

Why amniotic fluid is needed

The importance of the fluid in which the baby develops is very great. Amniotic fluid acts as a protective mechanism for the baby from environmental influences and compression by the muscles of the uterus. In case of danger, amniotic fluid acts as a shock absorber for the child, smoothing out shocks and shocks. Of course, if the shock is too strong, the amniotic sac may rupture, but weaker shocks will be successfully reflected.

Amniotic fluid for a child is nutrition, protection, and the environment. It contains all the necessary elements for the proper development and health of the fetus. This is a source of vitamins, protein and microelements for the baby. In the amniotic fluid, the baby is in a sterile and comfortable environment, as the fluid is constantly renewed.

During labor, the amniotic sac helps the cervix dilate. Infections that can penetrate the uterus from the vagina and infect the child are not able to penetrate the membrane of the amniotic sac.

Amount of amniotic fluid

The substance in which fetal development occurs is formed mainly from the mother's plasma by filtering and separating cells that form the inner lining of the membranes. The child himself also takes an active part in the formation of amniotic fluid. The fact is that at a later stage the child already swallows amniotic fluid and urinates in it. Every day the baby produces approximately 600 ml of urine, which is also part of the amniotic fluid.

At different stages of pregnancy, the amount of amniotic fluid is different. Amniotic fluid appears around the 8th week of pregnancy. Then there is a gradual increase in their number. By the tenth week, their volume is approximately 30 ml, gradually increasing. By the 38th week of pregnancy, normally, the amount of amniotic fluid should be from a liter to one and a half liters.

Before birth, the volume of amniotic fluid is usually reduced to 800 ml. This occurs due to increased fluid excretion from the mother's body. During childbirth, amniotic fluid and the placenta, which emerges from the woman's uterus, together amount to about 1800 g.

Consequences of oligohydramnios during pregnancy

An insufficient volume of amniotic fluid can be dangerous for both mother and baby. The most severe consequences for the development of the baby can occur in the presence of oligohydramnios during pregnancy from 15 to 25 weeks. Oligohydramnios at this stage usually leads to severe anomalies in the formation of the child’s internal organs. Usually these are pathologies in the development of the baby’s kidneys or face. In this case, the kidneys are formed incorrectly and may be too enlarged or completely absent. In this case, the child dies immediately after birth.

The presence of oligohydramnios in the first or second trimester of pregnancy with such severe pathologies in fetal development gives doctors reason to recommend termination of pregnancy. After all, with such terrible pathologies, the child is probably not capable of life and will die in the first day after birth.

Oligohydramnios can cause the umbilical cord to wrap around the baby's neck, which can be dangerous during childbirth. The risk of infection of the child in the womb also increases. If oligohydramnios is too severe, a fusion of the baby's skin and the amniotic membrane can form. This usually occurs in the form of thin threads that wrap around the baby and the umbilical cord, causing tissue death. Splicing also affects the blood circulation of the baby and the umbilical cord. It causes hypoxia in the baby and, as a consequence, his death.

During childbirth, oligohydramnios is dangerous because there may be weak labor, injuries and internal ruptures. Due to oligohydramnios, early placental abruption may occur and bleeding may begin. With oligohydramnios, the cervix does not dilate properly because the amniotic sac does not wedge itself between the baby's head and the cervix and does not help dilate it.

Oligohydramnios during pregnancy 32 weeks

By the third trimester of pregnancy, the volume of amniotic fluid should reach 800-1500 ml. Every three days, amniotic fluid is completely renewed, forming from the placenta and the walls of the amniotic sac.

But sometimes, as a result of the last ultrasound, a diagnosis is made of oligohydramnios. At this time, the causes of oligohydramnios may be late gestosis, disorders of the woman’s endocrine system, infection or hypertension. In addition, the amount of amniotic fluid may decrease due to leakage due to a violation of the integrity of the fetal membranes.

Analysis of the amniotic fluid index helps to assess the risk of oligohydramnios at this stage of pregnancy. This is done based on ultrasound. With a normal volume of amniotic fluid, this index ranges from 5 to 8, with moderate oligohydramnios, the AFI will be from 2 to 5, and with severe oligohydramnios, the AFI will be less than 2.

During this period, oligohydramnios is also dangerous for mother and child. The baby may develop pathology of internal organs, curvature of the spine, and fusion of the membranes with the baby’s skin. For a woman, oligohydramnios is dangerous during childbirth. It can cause painful and ineffective contractions and cervical injuries.

At 32 weeks of pregnancy, treatment for oligohydramnios is carried out depending on the cause that caused it. For example, if a pregnant woman has amniotic fluid leakage, then a smear test is required. Depending on the result of this study, a decision on further treatment is made. If there is intrauterine infection of the child, then antiviral treatment is prescribed along with taking vitamin complexes. With any treatment, regular monitoring of the amniotic fluid index and the condition of the pregnant woman and child is required. The course of treatment must be carried out during hospitalization in a hospital.

Treatment of oligohydramnios

It is very important to identify oligohydramnios in time and carry out its correct treatment. This can greatly affect the development and health of the baby, and even save his life. Doctors decide how to treat this disease after identifying the causes that provoked it. Also, it is important at what time oligohydramnios was detected and the degree of its severity.

Diagnosis of oligohydramnios in the early stages, as well as the detection of malformations of the child that threaten his life, usually leads to termination of pregnancy. If aging of the placenta, that is, fetoplacental insufficiency, has led to oligohydramnios, then treatment will be prescribed. Most often, doctors prescribe a course of Actovegin or Curantil. In this case, treatment can be carried out at home, without mandatory hospitalization.

If a child develops hypoxia due to oligohydramnios, doctors usually perform emergency surgery. In this case, the woman undergoes a caesarean section to save the baby's life, even if the pregnancy is premature.

In case of full-term pregnancy and existing oligohydramnios, the decision on further actions is made based on the condition of the child. If the fetus feels normal, then there is no need for treatment; a normal birth is carried out. But with oligohydramnios, labor very rarely begins spontaneously. As a rule, in order to provoke labor, a woman has her amniotic sac pierced, because it does not contribute to the dilatation of the uterus. In very severe cases, when the baby is entangled in the umbilical cord or when the baby is not positioned correctly, a decision is made to perform a caesarean section. The serious condition of a woman or child also becomes an indication for surgical intervention.

During treatment, the doctor constantly monitors the condition of the pregnant woman and the fetus using ultrasound, Doppler and CTG. This is done in order to take timely measures if there is a threat to the life of the child or mother.

It is impossible to treat oligohydramnios using traditional methods. Only impact on the cause of oligohydramnios is allowed. For example, if oligohydramnios is caused by hypertension, then you can try to correct the pressure using traditional methods. But oligohydramnios itself cannot be cured in this way.