For the full development of the baby, "living" during pregnancy in the mother's tummy, an obligatory supply of oxygen and nutrients is required. The placenta is directly involved in this.
What is it?
Placental tissue is a special specific organ that appears in the female body only during pregnancy. It begins to function actively by the beginning of the second trimester and persists until the very birth. The main function of the placenta is to protect the child from the effects of the external environment, as well as to participate in ensuring the blood flow necessary for its growth and development.
The placental tissue contains many different blood vessels through which important substances enter the fetus. The intensity of intrauterine development of the fetus largely depends on what structure the placenta has and where it is located.
Usually, placental tissue forms in the immediate vicinity of the implantation site of a fertilized egg. In most pregnancies, implantation occurs in the upper part of the uterus - its fundus. Typically, the fertilized egg is attached to the back wall, where the best blood flow occurs. However, this situation is not always possible. Sometimes it also happens that the attachment of a fertilized egg occurs much lower - in the lower parts of the uterus. In this case, the placental tissue is formed and is located quite close to the internal uterine pharynx.
If the distance between the pharynx and the placenta is greatly reduced, then this clinical condition is called low position. This can be very dangerous as the pregnancy usually gets worse.
If the placental tissue "enters" the area of the internal uterine pharynx, then this pathology is already called presentation. In order to assess the presence of this pathology, doctors must evaluate the distance between the internal uterine pharynx and the placenta itself. In each segment of pregnancy, the rate of this indicator is different. In the second trimester, the placenta should be normal 5 cm above the uterine pharynx. In the third trimester, this value increases to 7 cm.
Presentation can be different. Physicians use special classifications that include several clinical options. One of the rather unfavorable options is complete placenta previa. In this case, almost all placental tissue overlaps the uterine pharynx. In this situation, the placenta is located critically low in relation to the external female genital organs. In this case, the risk of developing adverse complications of the course of pregnancy increases many times.
Causes of occurrence
A variety of causal factors can lead to the development of full presentation. Most often, this pathology is facilitated by chronic diseases of the female genital organs. Pathologies that occur with the development of persistent inflammation are accompanied by damage to the inner mucous membrane of the uterus. Changes in the structure of the mucous membrane contribute to the fact that the fertilized egg simply cannot attach to the uterine wall in the region of its bottom. It begins to descend into the underlying departments, which leads to the formation of placenta previa.
One of the predisposing factors for the development of this pathology may be previous surgical operations on the reproductive organs. Curettage of the uterine walls, removal of myomatous nodes and various neoplasms are risk factors for the development of placenta previa. Doctors note that this pathology is more common in women who give birth to a second and subsequent babies.
Usually, the likelihood of developing placenta previa in a subsequent pregnancy is slightly higher in women who have previously had a caesarean section. And also the existing scars on the uterus that have arisen after gynecological operations can lead to the development of presentation.
How to identify?
It is now quite easy to locate the placenta. Doctors can be helped with this by both a regular vaginal examination and an ultrasound test. A more accurate method for diagnosing this pathology, of course, is ultrasound. Modern devices, with the help of which survey data are carried out, make it possible to calculate the distance between the placenta and the uterine pharynx with an accuracy of a fraction of a centimeter. Complete placenta previa is a pathology that necessarily requires dynamic monitoring by doctors. For this purpose, specialists usually prescribe the expectant mother to undergo several ultrasound examinations at a certain frequency.
To assess the localization of the placenta in full presentation, doctors most often use transabdominal ultrasound. Transvaginal examinations and vaginal examinations can be fraught with bleeding.
If you cannot do without them, then in such a situation it is very important that the examinations are carried out by experienced and qualified specialists who will perform them as carefully and accurately as possible. The position of the placenta is also necessarily assessed immediately before childbirth.
Features of the development of pregnancy
When establishing a diagnosis of placenta previa, a more careful and attentive attitude of doctors is required. For the expectant mother, individual recommendations are made to correct her lifestyle, which she must impeccably follow. It is important to remember that during the course of such a complicated pregnancy, life-threatening conditions can occur at any time.
Usually, the first unpleasant signs appear in the 2nd trimester of pregnancy. With full placenta previa, they can develop in the 3rd trimester, and also disturb a woman almost until the very birth. In this case, it is important to be sure to monitor the well-being of the mother and child, as well as to prevent possible dangerous conditions for their lives.
If the expectant mother, who has placenta previa during pregnancy, feels a sharp deterioration in her condition, then she should definitely see her obstetrician-gynecologist.
Complications
Pregnancy, complicated by placenta previa, is often not entirely smooth. Only in rare cases, carrying a baby does not cause any discomfort to the expectant mother. As a rule, a pregnant woman has various complications that exacerbate the course of pregnancy. The most dangerous of them are the following:
- development of bleeding from the genital tract;
- detachment of the placenta from the uterine wall;
- violation of the intrauterine process of fetal development due to impaired blood flow through the uteroplacental vessels;
- development of fetal hypoxia.
These clinical conditions usually develop in combination. The severity of adverse symptoms largely depends on how pronounced placenta previa is. With full presentation, these symptoms develop quite often. The course of this pathology is difficult to predict. A variety of reasons can lead to the development of complications.
So, bleeding from the genital tract can occur after lifting weights or engaging in intense physical activity. Even severe psycho-emotional stress can lead to a worsening of the course of pregnancy.
Bleeding from the genital tract is one of the most common and unfavorable complications. The appearance of blood on underwear is usually noticed by the expectant mother herself. At the same time, blood clots can have a different color: from dark brown to bright red.
In pregnancy complicated by full placenta previa, it is very important to remember that when blood appears from the genital tract, you should immediately seek medical help. If the bleeding does not stop for several hours, and the well-being of the pregnant woman worsens, then in such a situation, an ambulance team should be called immediately.
The arriving doctor can assess the general condition of the expectant mother and, if necessary, refer her to hospitalization in a hospital.
While in the hospital, the expectant mother will receive treatment aimed at improving her well-being. At the same time, doctors will definitely evaluate the general condition of the fetus. If the threat to the child's life is too great, and the gestational age is already sufficient for childbirth, then in such a situation, a decision will most likely be made to urgently perform surgical obstetric aid.
Frequent bleeding from the genital tract is dangerous for the development of an extremely unfavorable condition for the expectant mother and her baby - anemia. An anemic condition is characterized by a decrease in the amount of hemoglobin or red blood cells in the blood. Anemia has a negative effect on the intensity of intrauterine development of the fetus, and also significantly impairs the general well-being of a pregnant woman. To compensate for the violations that have arisen, the expectant mother is prescribed medications containing iron.
Another dangerous complication of presentation is placental abruption. It usually develops after some kind of mechanical impact. Detachment of placental tissue can be minor or very massive.
Because, how much the placenta has detached from the uterine walls will depend on the severity of this pathology. In some cases, the placenta exfoliates so much that the blood supply to the fetus is rapidly disrupted. In this case, the child may experience hypoxia - this is oxygen starvation of internal organs.
Disruption of the supply of dissolved oxygen to the tissues of vital organs is dangerous because their full functioning may be disrupted.
How is labor done?
Management of pregnancy complicated by complete placenta previa is always individual. Over the entire period of bearing the baby, the general condition of the mother and the fetus can change several times. It is very important that at this time the pregnant woman is observed by an experienced and qualified doctor, who can suspect the development of various complications in time.
With full placenta previa, a caesarean section is the best choice for delivery. In this case, the possible risk of traumatic injuries and profuse bleeding during spontaneous natural childbirth is minimized.
It is very important to keep the pregnancy as long as possible. The later a child is born, the more chances he has that he will be adapted to life in a new environment. If the course of pregnancy, complicated by full presentation, can be controlled, then doctors can determine the future date of the upcoming caesarean section.
If the condition of the expectant mother in the late stages of pregnancy suddenly deteriorates greatly, then she will be hospitalized in a hospital.
For information on what to do if the doctor has identified a complete placenta previa, see below.
