Everything You Need To Know About Amniotic Fluid
Amniotic fluid is the fluid that surrounds the fetus during the gestation period within the mother’s womb. It plays a very important role in the growth and development of the fetus.
Composition of amniotic fluid
Amniotic fluid changes in its composition as gestation progresses. Likewise, its volume increases as it progresses, generally until week 32. From week 40, however, it begins to decrease.
Initially, it is the result of osmotic gradients. That is, at the beginning it is made up of plasma from maternal blood and substances from the placenta, the uterine membrane and the body surface of the embryo.
Then, once the fetus has developed urination and swallowing, it is mainly formed by:
- Fetal urine.
- Fluid coming from the lungs.
- Oral and nasal secretions.
The fetus is continuously ingesting part of this liquid through the mouth and, at the same time, expelling it through the urine. This implies a regulation of the amount present in the amniotic sac, which gives it the necessary balance.
Features
Some of the most important functions of amniotic fluid are:
- Protective function against trauma or external shock.
- Shock absorbing effect for the fetus and the umbilical cord within the maternal uterus.
- Protection and defense against infections.
- Deposit of food and growth factors for the fetus during gestation.
- Helps keep the fetus temperature constant.
- It contributes to the maturation of the lungs, thanks to the presence of various enzymes.
- It allows the development of the fetal musculoskeletal, gastrointestinal and pulmonary systems.
Pathologies related to amniotic fluid
Alterations in the amount of fluid
During pregnancy, variations in the amount of amniotic fluid can occur, both by excess and by default, for various reasons. Both are pathological:
- Oligohydramnios: little amount of fluid. It is associated with complications such as the following:
- Early induction of labor.
- Low-weight fetuses.
- Fetal bradycardia during delivery.
- It can lead to fetal death.
- Polyhydramnios: excessive amount of fluid. It is associated with complications, especially maternal, such as:
- Gestational diabetes.
- Hypertension during pregnancy.
These alterations are generally detected by ultrasound measurement of the volume of amniotic fluid. This measurement is carried out through the Amniotic Fluid Index or ILA. To obtain this data, the uterus is divided into four quadrants and the free areas of the fetus and the umbilical cord are measured in vertical centimeters. A normal ILA between 8 and 21 cm is considered.
Amniotic fluid embolism
Another related pathology is amniotic fluid embolism. It consists of foreign matter entering the mother’s blood circulation, such as fetal meconium. It is a very serious condition that can cause systemic hypoxia, as well as alterations in coagulation.
Meconium amniotic fluid
Finally, we highlight another aspect to take into account. We call the presence of meconium in the amniotic sac meconium amniotic fluid. Meconium is the intestinal secretion of the fetus, that is, its first poop. Generally, this evacuation occurs after birth.
However, sometimes, especially in babies who stay longer inside the mother, this can occur before going outside. We speak, in that case, of liquid or colored waters.
The normal thing is that, when the mother breaks water, the liquid is transparent or yellowish. If, on the contrary, it is opaque, greenish and thick, it indicates the presence of meconium. In this case, the specialist should assess the situation, as it can be an indicator of fetal distress.
Conclution
Amniotic fluid plays a very important role in the development and well-being of the fetus during pregnancy. Apart from being a protection measure against blows, it acts as a reservoir of nutrients and allows the development of the fetal musculoskeletal, gastrointestinal and pulmonary systems. Any alteration in it can cause significant damage.
Likewise, its prenatal study and analysis is of great help in the detection of congenital defects, such as chromosomal diseases. It is carried out through amniocentesis. However, this technique is also associated with great risks that must always be considered before exposing a patient to them.
