In order to communicate between the mother’s body and the fetus, the placenta acts as the intermediary for the exchange of nutrients and it is essential to be able to support, protect and develop the baby during pregnancy. It has the role to filter the mother’s blood when passing to the fetus, removing everything that can be harmful to them. It also provides oxygen, glucose, calcium, water, and other substances to the baby, in addition, to protect the mother’s belly from harsh impact as well as providing an immune system to the fetus.
And it works the reverse way too: the placenta removes the baby’s waste and carbon dioxide, passing it to the mother to then be eliminated. It also helps by stimulating hormones in pregnancy such as estrogen, progesterone, and lactogen, which are super important for the production of breast milk. The placenta is also responsible for controlling the human chorionic gonadotropin hormone, which is only produced during pregnancy and is responsible for fixing the embryo in the uterus.
Weighing about 500 grams, the organ consists of two sides: one in direct contact with the mother’s uterus, while the other part is connected to the baby, through the umbilical cord.
How the placenta is formed
The placenta is formed as soon as the fetus is implanted in the uterus and its formation is composed of cells from both the uterus and the baby. The placenta grows fast and when it is nine months old it is already bigger than the fetus, although the baby is already heavier than the placenta at this stage. At about 4 months of gestation, the placenta is the same size as the fetus.
The placenta is only eliminated at the time of delivery, either by natural or cesarean birth. When the delivery goes accordingly, the placenta usually leaves spontaneously after 4 to 5 uterine contractions, which usually hurts much less than uterine contractions when the baby is ready to come out.
During a healthy pregnancy, the placenta remains whole throughout the gestation so that the baby can develop well. However, the placenta can undergo some changes during pregnancy, which can harm the mother and baby if the necessary care isn’t taken when needed. The changes in the placenta that can affect the baby are:
Placental insufficiency
This bad formation makes it difficult for the mother and baby to exchange nutrients and substances. Therefore, it can cause some difficulty in the growth of the fetus or even a restriction in their development. The main cause of placental insufficiency is hypertension, but it can also be caused by smoking, alcohol, and drugs. It can also happen due to genetic factors.
Low or previa placenta
If the placenta stays low in your womb, near to or covering your cervix, it may block the baby’s way out. The position of the placenta influences childbirth, and it may happen that it is in front of the fetus and, in these cases, there is a risk of the placenta coming off, which could cause the baby’s death. Because of this, in most of these cases, experts recommend cesarean childbirth.
Placental abruption
It happens even when the placenta is formed in the ideal place, but its connections to the uterus are broken, thus hindering the flow of substance that is passed to the baby, such as oxygen, essential for its development and survival. Depending on the displacement, an emergency cesarean is required. If this displacement is only partial, there is the possibility of the pregnancy continuing until the baby is able to survive well outside the womb.
Accreta Placenta
It happens when the placenta improperly fixes in the uterus, making it difficult to leave at the time of Childbirth. This bad formation can lead the mother to hemorrhage which, in many cases, will require a blood transfusion. In the most serious cases, even the removal of the entire uterus, in addition to endangering the mother’s life.
Calcified or aged placenta
The placenta aging is normal and complications will depend a lot on its degree of development. For example, when the placenta is classified as grade III, before 34 weeks of gestation, it can slow the development of the fetus. In most cases, the mother doesn’t show any symptoms and this change is only diagnosed by routine ultrasound with specialists.
Placental infarction or placental thrombosis
This pathology can happen due to the clogging of blood vessels of the placenta, causing thrombosis and resulting in the decrease of blood that goes as a nutrient for the baby. In some cases, it goes unnoticed through the pregnancy, causing no problems, but it can also cause a miscarriage. Therefore, it is always good to have continuous monitoring with your doctors.
Uterine rupture
It is when the uterine musculature breaks during pregnancy or childbirth. This is a type of complication very difficult to happen and when it does, it is treated in surgery during childbirth. However, it is very serious and can cause premature childbirth and even the death of the mother or baby. Symptoms include severe pain, vaginal bleeding, and a decrease in the baby’s heart rate.
The only way to prevent or pay attention to any changes in relation to the placenta, even before the appearance of serious complications, is through routine consultations with your obstetrician and making sure you do all the ultrasound exams of each stage of pregnancy. And, as always, in case of any apparent symptoms, do not hesitate to seek medical help.