The fetus developing in the womb receives all the substances it needs for development from the mother’s blood. This process occurs due to temporary internal organs appearing during pregnancy - chorion and placenta.
At the very beginning of pregnancy, chorion appears - these are many outgrowths in the membrane surrounding the fetus, which gradually penetrate the walls of the uterus, increasing in size and turning into the so-called. chorionic villi. At the end of the first trimester, the chorion transforms into " children's place" - the placenta. The placenta looks like a large suction cup attached to the wall of the uterus.
The blood of the fetus circulates in the vessels of the placenta thanks to the convolutions of the chorion, and then the placenta, buried deep into the uterine wall.
Chorionic presentation
For normal gestation, very important point is the localization of the chorion, that is, the place of its attachment to the wall of the uterus.
There is a medical term - chorion presentation (and then). This term means the localization of the chorion in the lower part of the uterus close to the transition of the uterus to the cervix, that is, close to the so-called. internal os. This arrangement of the chorion and placenta creates conditions for severe bleeding during pregnancy and childbirth and for miscarriage. Moreover, sometimes due to placenta previa, the doctor decides to perform C-section, because natural childbirth in such a situation may be impossible.
Anterior localization of the chorion
Anterior localization of the chorion is one of the types of presentation, when the chorion moves to the cervix from the anterior. This localization of the chorion is more likely a norm than a violation, since the cervix practically does not close. Therefore, we can say there is no reason for concern. It is important that the chorion is located 3 cm or more above the internal os in the cervical canal. In passing, we note that when the chorion is presented along the anterior wall of the uterus, its upward mutation occurs much faster.
When the chorion is located along the anterior wall, the placenta subsequently grows along the wall of the uterus that is closer to the mother’s abdomen. With this option, some complications may occur:
- due to the location of the fetus behind the placenta, its heartbeat is heard worse, and it is more difficult to feel the baby’s movements;
- Caesarean section is more difficult to perform;
- after a previous cesarean section in a previous birth, the placenta may adhere to the muscular layer of the uterus.
The chorion is one of the membranes of the placenta. It is part of the placental barrier (it is its middle layer) and plays a large role in the metabolism of the fetus. In obstetrics, the phrase chorion previa is not entirely correct, because it is only one of the membranes of the placenta (middle), so the phrase “placenta location” is more often used. The fundus of the uterus or the upper segment of the posterior wall is predominant. But sometimes the chorion is located along the anterior wall of the uterus or in the lower segment of the uterus. Our article will discuss the features of pregnancy when the chorion is localized along the anterior wall.
Chorion location options
The most common localization of the chorion is back wall the uterus with a transition to the lateral surfaces, with this arrangement of the chorion the most favorable course of pregnancy. Localization of the villous chorion along the anterior wall is considered a normal variant. If the chorion is located high on the anterior wall, then there is no threat to pregnancy (at least 3 cm from the internal os of the cervix).
Chorion appears on early stages formation of the embryo, it is responsible for nutrition of the future fetus until the 13th week of pregnancy. From the 13th week, the placenta takes over this function. Initially, the chorion looks like small outgrowths surrounding the embryo; subsequently, these outgrowths increase and turn into chorion villi.
Chorionic presentationPresentation or anterior poses a threat to pregnancy. A marginal presentation is identified (the edge of the placenta partially covers the internal os of the cervix) and full presentation(the placenta completely covers the internal os of the cervix). Such pregnant women require special monitoring, as they are at risk for obstetric hemorrhage. If chorion presentation occurs along the anterior wall, then the risk of bleeding is slightly higher, because the lower segment of the anterior wall of the uterus stretches better and faster and sometimes outstrips the growth of the placenta, which provokes bleeding.
We examined the features of pregnancy when the chorion is localized along the anterior wall. In the case where the chorion is located in the upper third of the uterus, pregnancy is not in danger. If the chorion is attached to the anterior wall of the uterus, in its lower third, then the risk of premature placental abruption increases.
Chorion- the outer germinal membrane that surrounds the embryo. It appears at the very beginning of pregnancy and looks like elongated outgrowths of the membrane surrounding the embryo, which penetrate deep into the wall of the uterus. The outgrowths of the chorion increase in size as pregnancy progresses and turn into villi, through which metabolism occurs. At the end of the first trimester of pregnancy (at the 13th week), the chorion turns into the placenta, which looks like a large round “suction cup”, with the help of which the fetus is attached to the wall of the uterus.
The blood of the mother circulates in the vessels of the uterine wall, and the blood of the fetus circulates in the vessels of the placenta. The convolutions of the chorion (and later the placenta) penetrate deep into the wall of the uterus, so the vessels of the mother and fetus are located very close, which allows for the exchange of substances between the blood of the fetus and the blood of the mother. In addition, the chorion and placenta produce hormones (progesterone,) that support the development of the fetus and protect it from aggressive influences immune system maternal body.
For the normal course of pregnancy, the location of the chorion is very important.
Chorion along the anterior wall
If the chorion is localized in the anterior region, there is no cause for concern, since this location is one of the normal variants and, as a rule, ensures the normal course of pregnancy and childbirth. The main thing is that the chorion is located above the internal os cervical canal three or more centimeters. It is worth noting that when the chorion is attached to the anterior wall of the uterus, as pregnancy progresses, it migrates upward much more quickly.
When the chorion is located along the anterior wall, it will then develop along the wall of the uterus, located closer to the woman’s abdomen. With this version of the norm, some difficulties are possible:
- due to the fact that the baby is located behind the placenta, his heartbeat is less clearly heard;
- it is more difficult for a woman to feel the baby move;
- performing a caesarean section in this case may be associated with certain difficulties;
- after a previous birth by cesarean section, it is possible for the placenta to accrete to the muscular layer of the uterus. The risk of such a complication is proportional to the number of surgical interventions. Therefore, without medical indications women are not recommended to resort to them during childbirth.
Life little man Before birth, the inside of the mother is provided, first of all, by many vessels, the umbilical cord, and the placenta. He receives from his mother's blood a large number of nutrients and oxygen. The metabolism between mother and child is ensured by two vital organs for the fetus - the placenta and.
The chorion, appearing at the very beginning of pregnancy, develops along with the fetus, turning into villi. By the end of the 1st trimester, it transforms into the placenta, with the help of which the baby is attached to the wall of the uterus. Much attention is given to the location of the chorion.
What does predominant localization of the chorion mean?
The location of the chorion can be on the front, back upper, or one of the side walls. Localization of the chorion on the upper wall (fundus of the uterus) is also considered normal.
If the fetus is attached to the lower wall of the uterus, then the chorion is said to be low on the anterior wall (2-3 cm from the uterus to the cervix). This arrangement of the chorion along the anterior wall is diagnosed in more than 6% of pregnant women. The identified place of chorion attachment is not final, because in most cases, the chorion migrates from a low position to a higher one, which helps to avoid problems associated with the localization of the chorion in the area of the internal pharynx.
What dangers are associated with low placenta or chorionic previa?This kind of stretching increases the risk of miscarriage and can also cause heavy bleeding, both during pregnancy and during childbirth. It is also an indication for caesarean section and even complete after childbirth. Normal birth possible only when the placenta is located no closer than 2 cm to the exit.
Summarizing our article, we point out that a woman should not be afraid of the peculiarities of the localization of the chorion; the main thing is to pay attention in time to the possibility low presentation on latest dates and follow your doctor's instructions.
The first weeks of pregnancy for expectant mother are probably one of the most difficult periods throughout the entire period of pregnancy. At this time there are several “critical periods” in the life of the future little man; his mother is mentally and physically rebuilt for a successful pregnancy. Unfortunately, this period does not always pass without complications and problems, so routine ultrasound examinations should be carried out. A woman’s first ultrasound is scheduled for the end of the first trimester, and it is at this time that this pathology is most often detected.
How dangerous is chorion presentation at 12 weeks, and how to prevent complications?
Chorionic presentation during pregnancy - what does it mean?:
Chorion is special body, which provides a connection between the mother’s body and her unborn child. Essentially this is early stage development of the placenta, therefore the term “chorion” is used only during the first three months of gestation, after which the word “placenta” is already used. One surface of the chorion faces the fetus, and the other is attached to the wall of the uterus. And it is precisely when the location of the chorion is atypical that various disorders can occur.
As you know, the uterus communicates with the vagina and external genitalia through the cervix, inside which there is a special cervical canal. The internal opening of this canal, which breaks off into the uterus, is called the os of the cervical canal. The chorion or placenta is normally attached to the bottom or lateral surfaces of the uterus and does not overlap the pharynx in any way. But in some cases they can partially or completely close the internal opening of the cervical canal - it is in this situation that a disorder called "Chorion presentation"
Types of presentation:
The closure of the cervical canal by the chorion does not have to be complete, therefore there are several types of presentation that characterize the complexity of this condition:
Partial chorion presentation. In such a situation, the developing placenta covers at least two-thirds of the lumen of the cervical canal.
Regional chorionic presentation . This is a variety and, one might say, more easy option partial presentation, since only one third of the lumen of the pharynx is covered.
Central chorion presentation. In this case, the lumen of the pharynx of the cervical canal is completely closed by the future placenta, which significantly complicates the course of pregnancy and poses a threat to both the unborn child and the life of the mother.
Low location of the chorion . The forming placenta can be located next to the opening of the cervix, but not block it. If it is attached near the edge of the pharynx closer than three centimeters, then it is said to be low. This is not a dangerous phenomenon, but creates potential threat for pregnancy.
Chorionic presentation at week 12 can be in any of these forms.
As pregnancy progresses, the growing uterus can pull back the placenta, so central presentation can turn into partial and marginal, and then disappear completely. According to obstetricians, more than 90% of cases of one or another chorionic presentation completely disappear over time, so if you were diagnosed with it in the first weeks of pregnancy, this is not a reason to panic. But you will have to monitor your condition and not neglect examinations by a specialist.
Causes of presentation:
Why exactly the developing placenta is attached in such dangerous proximity to the pharynx of the cervical canal is completely unknown. However, several main factors have been noted that contribute to more likely development of this complication during pregnancy. Especially often various options Chorionic presentation develops in women who have had in the past or currently have the following diseases and conditions:
Inflammatory lesions of the uterus, abortions, especially using the curettage method, surgical interventions for fibroids or cesarean section. All these factors are united by one consequence - after this, scars and adhesions can be left on the inner surface of the uterus, which make it difficult for the chorion to attach to the “right” place.
Diseases of the liver, kidneys or heart. It would seem, how can these conditions affect the position of the fetus and its placenta in the uterus? But with pathologies of these organs, blood stagnation may occur in the pelvic area, which contributes to lower attachment of the chorion.
Multiple births in the past. If you are pregnant not for the first time, then your chances of improper attachment of the chorion significantly increase. Most physiologists see the reasons for this phenomenon in the fact that after each pregnancy, in the area of the uterus where the placenta was attached, the structure of the endometrium changes. Therefore, at the next conception, the chorion can no longer attach there. Over time, such places on the inner surface of the uterus become less and less, which leads to the attachment of the placenta in the danger zone.
Uterine deformities, acquired (for example, after surgical interventions) or congenital in nature, can also lead to chorion presentation.
Is chorionic presentation dangerous?:
Most pregnant women are frightened by such a conclusion from the very first ultrasound examination. Although in fact, chorionic presentation during pregnancy of 10-13 weeks is observed in approximately 5% of cases, that is, in every twentieth woman. In more later this condition is becoming increasingly rare, occurring before birth in no more than 0.5% of women in labor. The main reason for this is that the growing uterus is able to “pull” the chorion attachment point from the cervical canal to a safer area. Therefore, according to pediatricians, chorion presentation during the first trimester can be regarded as a feature of the course of pregnancy, but not a complication.
Difficulties begin if the presentation continues to persist after the third month of pregnancy. Being dangerously close to the pharynx of the cervical canal, the placenta can be easily injured, which leads to bleeding of varying degrees. With edge or partial presentation first bloody issues appear closer to the sixth month. They are practically painless, and blood may be released in thin streaks in the discharge, or give the impression of menstruation. Central presentation can manifest itself with such symptoms as early as the second or third month. In fact, this is the main consequence and danger of chorion presentation, which entails a number of disruptions to the course of pregnancy and the health of the mother and her unborn child:
The constant loss of small amounts of blood leads to anemia in a pregnant woman. You may experience weakness, dizziness, skin become pale. In case of severe bleeding, blood pressure may decrease, vision may become dark, and you may even lose consciousness.
Disruption of connections between the uterus and placenta also leads to malnutrition of the unborn baby. Its development slows down, and against the background of reduced oxygen delivery (due to a damaged placenta and anemia in the mother), intrauterine fetal hypoxia occurs.
If the mother's blood loss reaches significant levels, this can lead to miscarriage, intrauterine death fetus and a number of other terrible consequences.
In addition to the problems described, presentation is often complicated by improper positioning of the fetus, which leads to difficulties during the birth process. Therefore, if such a condition is diagnosed in you in the sixth month or later, then you need to mentally prepare yourself for the fact that you may have to have a caesarean section rather than give birth on your own.
Treatment of chorionic presentation:
Unfortunately, at the moment, doctors do not yet know how to correct such a condition as chorionic presentation, so all treatment comes down to preventing complications and eliminating their consequences. As a rule, if there is a central presentation in the fourth month, they prefer to place the girl in the position in a hospital for preservation. The same is done with partial forms of presentation, if they are complicated by bleeding, hypertonicity of the uterus and other factors that may threaten termination of pregnancy. In a hospital setting you will be provided with the following treatment:
To begin with, strict bed rest and limitation of physical activity, which is one of the the most important factors prevention of bleeding with placenta previa. In addition, you will need to avoid emotional stress, as this can also lead to negative consequences.
Regular examination by a doctor and diagnostic ultrasound examinations. Being under 24-hour medical supervision, you greatly reduce the risk of sudden complications, since they will be identified and corrected as quickly as possible. short term. Most deplorable and even tragic situations with chorion presentation are caused by delayed medical intervention.
Maintenance treatment, which includes all the vitamins necessary for the pregnant body.
Proper and regular nutrition, which normalizes the functioning of the gastrointestinal tract. If you have diarrhea or constipation, you may strain your abdominal muscles, which increases pressure in the pelvis and can trigger bleeding.
If you develop anemia due to bleeding, it can be treated in a hospital setting by taking iron supplements, including those given by injection.
Treatment is also prescribed to eliminate other factors that threaten the course of pregnancy - for example, antispasmodics for uterine hypertonicity.
In case of partial chorionic presentation, which does not manifest itself with severe symptoms, you do not have to go to the hospital for preservation, but you need to follow certain precautions for prevention possible complications. These primarily include:
Exercise stress. Leisurely walks and walking around the house is the maximum for a girl in such a situation. Lifting heavy objects, walking up stairs, and running are strictly contraindicated.
It is necessary to completely avoid sexual contact. During pregnancy, in principle, sexual intercourse is not prohibited at almost any stage, but during presentation it can cause severe bleeding.
Mental stress or stress affects the pregnant body no better than lifting weights. Therefore, they also need to be excluded, and even with sedentary and predominantly mental work, it will be time for you to go on maternity leave.
Also, as with preservation, it is necessary to eat properly so as not to cause changes in stool and at the same time provide the body with all the necessary nutrients. You also need to agree with your doctor on the choice of a vitamin complex, which will be very useful in such a situation.
And most importantly, if you have been diagnosed with chorionic presentation and at some point you find a discharge even small quantity blood in the absence of pain, weakness and other symptoms, you should immediately consult a doctor. And if the bleeding is accompanied by pain in the lower back and lower abdomen, palpitations, weakness or fainting, then you need to call “ Ambulance"as soon as possible, as you risk losing your child.
