The placenta is a fundamental organ in pregnancy , since it constitutes the vital connection of the baby with the mother. Its name comes from Latin and means “flat cake”, referring to its appearance in humans. It is the only temporary organ in the human body that forms during pregnancy and fulfills a specific function during pregnancy.
The placenta begins to form at the same time as the implantation of the embryo in the uterine wall, an event that occurs approximately a week after fertilization has occurred. The placenta develops from the same cells from the sperm and egg that gave birth to the fetus.
What is the placenta for?
Its main mission is to transmit nutrients to the baby . The level of blood flow to the uterus is about 500-700 ml per minute. Thanks to this blood, it supplies the baby with oxygen (it functions as a “fetal lung”), nutrients and hormones. It also takes care of the baby’s waste, especially the carbon dioxide that passes into the maternal bloodstream to eliminate it. The mother then removes these wastes through the kidneys.
So the placenta acts as a filter in charge of keeping these harmful substances away from your baby’s body system.
Another mission is the endocrine function, that is, the manufacture of hormones , including human chorionic gonadotropin, which is what allows the pregnancy to continue. This hormone is what is measured in pregnancy tests .
It also synthesizes estrogens or female-type sex hormones, which play a very important role in embryo implantation, breast development, and placental lactogen, which controls maternal metabolism and stimulates the growth of the baby.
All of these hormones help make sure that a woman’s body goes through the appropriate changes during pregnancy.
Although many microorganisms such as bacteria, germs or toxins are not capable of crossing the placenta, so the fetus is protected during a time when its immune system is not mature, most viruses are capable of crossing or breaking this barrier.
What is the placenta made of?
The placenta is made up of a maternal component (which is a transformation of the uterine membrane or mucosa) and another part of fetal origin (trophoblast). The fetal side of the placenta is made up of hundreds of intersecting blood vessels. In the evolution of the trophoblast, the chorionic plate is generated with the different placental components.
The maternal portion is the outermost part of the placenta, in contact with the uterine wall, which is why it is called the basal plate. It consists of embryonic tissue as well as maternal tissue (the decidua basalis with the uterine glands and vessels).
Where is the placenta located?
Once implanted and firmly attached to the uterine wall, the placenta does not move. It can move and change location within the uterus, since the uterus is like a balloon that swells throughout the nine months of gestation.
Normally the placenta is on the front or back of the uterus , without interfering with or blocking the cervix, which is where the baby is to be born through the birth canal. It is called placenta previa when the placenta is attached to the lower part of the uterus.
The placenta previa can be occlusive, if it completely plugs the cervix, or non-occlusive, if the plugging is not total.
How long does the placenta live?
Like any organ, the placenta has a biological process: it is born, grows and dies . And how long does the placenta live? As much as pregnancy: approximately 40 weeks. It grows throughout the pregnancy, although in the last weeks of it it stagnates.
From the 41st week there is a greater risk that it does not work properly and stops transmitting the nutrients that the baby needs to grow, this is what is called “aged or old placenta”.
When the gestation ends, the placenta usually measures 1.5-3 centimeters thick and 15-20 centimeters in diameter and weighs around 450-550 grams, without taking into account the umbilical cord to which it is attached .
Labor does not end until the mother expels the placenta, that is, until the last phase of labor , called “delivery”, in which there are still contractions.
Once it is expelled, it should be checked that it is complete, since if there are remains inside the uterus, complications could occur. And in addition, the state of the placenta is controlled, which can give clues about the state of the baby.
Despite its rather impressive appearance (they say that some parents who witness childbirth only get dizzy when the placenta is delivered), the worship of this organ in different traditions and in various cultures attests to its importance.
In short, the placenta is an organ of vital importance for the growth and protection of the fetus in the womb, but its meaning of “life” and its symbolism transcends the merely physiological.