Marginal low placentation. Placenta previa on the posterior wall

Update: October 2018

Placenta previa is rightfully considered one of the most serious obstetric pathologies, which is observed in 0.2 - 0.6% of all pregnancies resulting in childbirth. Why is this pregnancy complication dangerous?

First of all, placenta previa is dangerous due to bleeding, the intensity and duration of which no doctor can predict. That is why pregnant women with such obstetric pathology belong to a high-risk group and are carefully monitored by doctors.

What does placenta previa mean?

The placenta is a temporary organ and appears only during pregnancy. With the help of the placenta, the mother and fetus communicate, the child receives nutrients through its blood vessels and gas exchange occurs. If the pregnancy proceeds normally, the placenta is located in the area of ​​the fundus of the uterus or in the area of ​​its walls, usually along the back wall, moving to the sides (in these places the blood supply to the muscle layer is more intense).

Placenta previa is said to be present when the latter is located incorrectly in the uterus, in the area of ​​the lower segment. In fact, placenta previa is when it blocks the internal os, partially or completely, and is located below the presenting part of the baby, thus blocking the path for birth.

Types of choreon presentation

There are several classifications of the described obstetric pathology. The following is generally accepted:

Separately, it is worth highlighting low placentation or low placenta previa during pregnancy.

Low placentation- this is the localization of the placenta at a level of 5 or less centimeters from the internal os in the third trimester and at a level of 7 or less centimeters from the internal os during pregnancy up to 26 weeks.

A low location of the placenta is the most favorable option; bleeding during gestation and childbirth rarely occurs, and the placenta itself is prone to so-called migration, that is, an increase in the distance between it and the internal os. This is due to the stretching of the lower segment at the end of the second and third trimesters and the growth of the placenta in the direction that is better supplied with blood, that is, to the uterine fundus.

In addition, the presenting vessels are identified. In this case, the vessel/vessels are located in shells, which are located in the area of ​​the internal pharynx. This complication poses a threat to the fetus if the integrity of the vessel is damaged.

Provoking factors

The reasons that cause placenta previa can be associated both with the condition of the mother’s body and with the characteristics ovum. The main reason for the development of complications is degenerative processes in the uterine mucosa. Then the fertilized egg is not able to penetrate (implant) into the endometrium of the fundus and/or body of the uterus, which forces it to descend lower. Predisposing factors:

Chronic endometritis, numerous intrauterine manipulations (curettage and abortion), myomatous nodes lead to the formation of an incomplete second phase of the endometrium, in which it prepares for implantation of a fertilized egg. Therefore, when forming the chorion, she looks for the most favorable place, which is well supplied with blood and optimal for placentation.

The severity of the proteolytic properties of the embryo also plays a role. That is, if the mechanism for the formation of enzymes that dissolve the decidual layer of the endometrium is slowed down, then the egg does not have time to implant in the “right” part of the uterus (in the fundus or along the back wall) and descends lower, where it is implanted into the mucosa.

Symptoms of placenta previa

The course of pregnancy, complicated by placenta previa, is conventionally divided into “silent” and “pronounced” phases. The “silent” phase is practically asymptomatic. When measuring the abdomen, the height of the uterine fundus more than normal, which is due to the high location of the presenting part of the child. The fetus itself is often located incorrectly in the uterus; there is a high percentage of pelvic, oblique, transverse positions, which is due to the localization of the placenta in the lower part of the uterus (it “forces” the child to occupy correct position and presentation).

Symptoms of placenta previa are explained by its incorrect localization. The pathognomic sign of this obstetric complication is external bleeding. Bleeding from the uterus can occur at any stage of pregnancy, but more often in the last weeks of gestation. This has two reasons.

• Firstly, in term (Braxton-Hicks contractions), which promotes stretching of the lower part of the uterus (preparation for childbirth). The placenta, which does not have the ability to contract, “comes off” from the uterine wall, and bleeding begins from its ruptured vessels.
• Secondly, the “unfolding” of the lower segment of the uterus in the second half of pregnancy occurs intensively, but the placenta does not have time to grow to the appropriate size and it begins to “migrate,” which also causes placental abruption and bleeding.

Typically, bleeding always begins suddenly, often against the background of absolute rest, for example, in sleep. It is impossible to predict when bleeding will occur and how intense it will be.

Of course, the percentage of profuse bleeding with central presentation is much greater than with incomplete presentation, but this is not necessary. The longer the gestational age, the greater the chance of bleeding.

• For example, marginal placenta previa may not manifest itself at all at 20 weeks, and bleeding will occur (but not necessarily) only during childbirth.
• Low placentation most often occurs without clinical symptoms, pregnancy and childbirth proceed without any special features.

One of the typical characteristics of bleeding during presentation is its recurrence. That is, every pregnant woman should know about this and always be on guard.

• The volume of bleeding varies: from intense to insignificant.
• The color of the blood released is always scarlet, and the bleeding is painless.

Any minor factor can provoke bleeding:

• straining during bowel movements or urination
• cough
• sexual intercourse or vaginal examination

Another difference between placenta previa is the woman’s progressive anemia (see). The volume of blood lost almost always does not correspond to the degree of anemia, which is much higher. During repeated bleeding, the blood does not have time to regenerate, its volume remains low, which leads to reduced blood pressure, the development of disseminated intravascular coagulation syndrome or hypovolemic shock.

Due to the incorrect location of the placenta, progressive anemia and reduced volume of circulating blood, it develops, which leads to intrauterine growth retardation and the occurrence of intrauterine hypoxia.

Case study: A 35-year-old woman was seen at the antenatal clinic; she was pregnant for the second time and was wanted. At the first ultrasound at 12 weeks, she was diagnosed with central placenta previa. An explanatory conversation was held with the pregnant woman, and appropriate recommendations were given, but my colleague and I observed with fear and expectation of bleeding. During the entire period of pregnancy, she experienced bleeding only once, at 28–29 weeks, and even then, it was not bleeding, but minor bloody discharge. Almost the entire pregnancy the woman was on sick leave, she was hospitalized in the pathology ward at a dangerous time and during the period of bleeding. The woman safely reached term and at 36 weeks was sent to the maternity ward, where she successfully prepared for the upcoming planned caesarean section. But, as often happens, on a holiday she started bleeding. Therefore, an operating team was immediately convened. The baby was born wonderful, even without signs). The afterbirth was separated without problems, the uterus contracted well. The postoperative period also proceeded smoothly. Of course, everyone breathed a sigh of relief that such a huge burden had been lifted from their shoulders. But this case is rather atypical for central presentation, and the woman, one might say, was lucky that everything ended with little bloodshed.

How to diagnose?

Placenta previa is a hidden and dangerous pathology. If the pregnant woman has not yet had bleeding, then presentation can be suspected, but the diagnosis can only be confirmed using additional examination methods.

A carefully collected anamnesis (in the past there were complicated childbirths and/or the postpartum period, numerous abortions, diseases of the uterus and appendages, operations on the uterus, etc.), the course of the current pregnancy (often complicated by the threat of miscarriage) and external obstetric data helps to suggest a placenta previa. research.

During an external examination, the height of the uterine fundus is measured, which is greater than the expected gestational age, as well as incorrect position fetus or breech presentation. Palpation of the presenting part does not give clear sensations, as it is hidden under the placenta.

If a pregnant woman complains of bleeding, she is hospitalized in a hospital to exclude or confirm the diagnosis of such a pathology, where, if possible, an ultrasound is performed, preferably with a vaginal sensor. A speculum examination is carried out to determine the source of bloody discharge (from the cervix or varicose veins of the vagina).

The main condition that must be observed when examining with mirrors: the examination is carried out against the backdrop of a deployed operating room and always with heated mirrors, so that in case of increased bleeding, the operation can be started without delay.

Ultrasound remains the safest and most accurate method for determining this pathology. In 98% of cases, the diagnosis is confirmed; false positive results are observed when the bladder is overly full, so when examined with an ultrasound probe, the bladder should be moderately full.

Ultrasound examination allows not only to determine the presentation of the choreon, but also to determine its type, as well as the area of ​​the placenta. The timing of ultrasound examinations during the entire period of gestation is somewhat different from the timing of normal pregnancy and correspond to 16, 24 - 26 and 34 - 36 weeks.

How pregnant women are managed and delivered

If placenta previa is confirmed, treatment depends on many circumstances. First of all, the period of pregnancy when bleeding occurred, its intensity, the amount of blood loss, the general condition of the pregnant woman and the readiness of the birth canal are taken into account.

If chorionic presentation was established in the first 16 weeks, there is no bleeding and the woman’s general condition does not suffer, then she is treated on an outpatient basis, having previously explained the risks and given the necessary recommendations (sexual rest, limitation of physical activity, prohibition of taking baths, visiting baths and saunas).

Upon reaching 24 weeks, the pregnant woman is hospitalized in a hospital, where preventive therapy is carried out. Also, all women with bleeding are subject to hospitalization, regardless of its intensity and stage of pregnancy. Treatment of the described obstetric pathology includes:

• medical and protective regime;
• treatment of fetoplacental insufficiency;
• anemia therapy;
• tocolysis (prevention of uterine contractions).

The protective treatment regime includes:

• prescription of sedatives (tincture of peony, motherwort or valerian)
• maximum limit physical activity(bed rest).
• Therapy of fetoplacental insufficiency prevents fetal development delay and consists of prescribing:
  • antiplatelet agents to improve the rheological qualities of blood (trental, chimes)
  • vitamins (folic acid, vitamins C and E)
  • , cocarboxylase
  • Essentiale-Forte and other metabolic drugs
  • It is mandatory to take iron supplements to increase hemoglobin (sorbifer-durule c, tardiferon and others).

Tocolytic therapy is carried out not only in the case of a threatened miscarriage or threatening premature birth, but also for the purpose of prevention, the following are indicated:

• antispasmodics (magne-B6, magnesium sulfate)
• tocolytics (ginipral, partusisten), which are administered intravenously.
• in the case of threatening or beginning premature labor, prevention of respiratory disorders with corticosteroids and (dexamethasone, hydrocortisone) is mandatory for a duration of 2–3 days.

If bleeding occurs, the intensity of which threatens the woman’s life, regardless of the gestational age and the condition of the fetus (dead or nonviable), abdominal delivery is performed.

What to do and how to deliver a child with chorionic presentation? Doctors ask this question when they reach 37–38 weeks. If there is a lateral or marginal presentation and there is no bleeding, then in this case the tactics are expectant (the beginning of spontaneous labor). When the cervix is ​​dilated by 3 centimeters, an amniotomy is performed for prophylactic purposes.

If bleeding occurs before the onset of regular contractions and there is a soft and distensible cervix, an amniotomy is also performed. In this case, the baby’s head lowers and is pressed against the entrance to the pelvis, and, accordingly, presses the detached lobules of the placenta, which causes the bleeding to stop. If the amniotomy has no effect, the woman is delivered abdominally.

Caesarean section is routinely performed for those pregnant women who have been diagnosed with complete presentation, or in the presence of incomplete presentation and concomitant pathology (improper position of the fetus, pelvic end presentation, age, uterine scar, etc.). Moreover, the surgical technique depends on which wall the placenta is located on. If the placenta is localized along the anterior wall, a corporal cesarean section is performed.

Complications

This obstetric pathology is very often complicated by the threat of abortion, intrauterine hypoxia, delayed fetal development. In addition, placenta previa is often accompanied by its true accretion. In the third stage of labor and early postpartum period high risk of bleeding.

Case study: A multiparous woman was admitted to the obstetric department with complaints of bleeding for three hours from the birth canal. Diagnosis on admission: Pregnancy 32 weeks. Regional placenta previa. Intrauterine growth restriction of the 2nd degree (according to ultrasound). Uterine bleeding. The woman had no contractions, the fetal heartbeat was dull and irregular. My colleague and I immediately called the doctor. aviation, since it is still unclear how the matter may end other than the mandatory caesarean section. During the operation he was extracted alive. Attempts to remove the placenta were unsuccessful (true placenta accreta). The scope of the operation was expanded to hysterectomy (the uterus along with the cervix is ​​removed). The woman was transferred to the intensive care ward, where she remained for a day. The child died on the first day (prematurity plus intrauterine growth retardation). The woman was left without a uterus and a child. This is such a sad story, but, thank God, at least the mother was saved.

Placenta previa refers to its attachment to any part or all of the lower segment of the uterus and its relation to the internal os. The frequency of such pathologies is 0.5-0.8% of total number childbirth In the last decade, the frequency has increased and is explained by an increase in the number of abortions and intrauterine interventions. Bleeding with this diagnosis can occur at the beginning of the second half of pregnancy, due to the formation of the lower segment. Bleeding is most often observed in the last weeks of pregnancy, when uterine contractions begin to appear. Bleeding most often occurs during childbirth.

Complete placement is when the internal os is completely blocked by it and during vaginal examination tissue is detected everywhere; the membranes are not palpated. Incomplete (partial) - the internal os is not completely blocked and during vaginal examination, the placenta and amniotic membranes are determined behind the internal os. Incomplete - divided into marginal and lateral. With marginal, the lower edge is found at the level of the edge of the internal pharynx; with the side - the edge partially overlaps the internal pharynx. In both cases, the membranes are determined. Clinically, the option can be determined only when the uterine pharynx is dilated by 4-5 cm.

Low attachment - the lower edge of the placenta is located 7 cm or less from the internal os, the area of ​​the internal os does not cover and is not accessible for palpation during vaginal examination. Sometimes the rough surface of the membranes can be palpated, which allows one to suspect proximity.

Cervical (cervical-isthmus) - grows into the cervical canal as a result of inadequate development of the decidual reaction in the cervix. This is a rare but serious clinical situation; difficulties in diagnosis pose a fatal risk. This also includes cervical pregnancy.

During the normal course of pregnancy, it is usually located in the area of ​​the fundus or body of the uterus, along the posterior wall, with a transition to the side walls, i.e. in those areas where the walls of the uterus are best supplied with blood. It is located somewhat less frequently on the anterior wall, since the anterior wall of the uterus undergoes much greater changes than the posterior one. In addition, the location of the seat on the back wall protects it from accidental injuries.

If it only partially covers the area of ​​the internal pharynx, then this is incomplete attachment, which is noted with a frequency of 70-80% of the total. If it completely covers the area of ​​the internal pharynx, then this is a complete presentation. This option occurs with a frequency of 20-30%.

The causes of abnormalities in the location of the placenta have not been fully elucidated, but they can be divided into two groups:

• depending on the state of the woman’s body,
• associated with the characteristics of the fertilized egg.

The most common are pathological changes in the uterine mucosa that disrupt the normal decidual reaction of the endometrium. Chronic inflammation of the endometrium, scar changes in the endometrium after abortion, uterine surgery (caesarean section, conservative myomectomy, uterine perforation, etc.), uterine fibroids, abnormalities or underdevelopment of the uterus, multiple births, complications in the postpartum period. In multiparous women, the anomaly occurs more often (75%) than in primiparous women. Due to a violation of the nidation function of the trophoblast, namely the delayed appearance of enzymatic processes in the trophoblast, the fertilized egg cannot be implanted in the area of ​​the uterine fundus in a timely manner. It acquires the ability to implant, descending into the lower parts of the uterus, where it is grafted. Migration of the placenta is possible. Ultrasound examination allows you to track migration during pregnancy. At the beginning of pregnancy, the central location of the branched chorion is often determined. At the end of pregnancy, it migrates and can be located low or even normal.

The most common causes are pathological changes in the inner layer of the uterus (endometrium) due to inflammation, surgical interventions (curettage, cesarean section, removal of fibroids, etc.), and multiple complicated births. In addition, disturbances in placental attachment can be caused by uterine fibroids, endometriosis, underdevelopment of the uterus, isthmicocervical insufficiency, cervical inflammation, and multiple pregnancies. It should be noted that such presentation is more typical for repeatedly pregnant women than for first-time mothers. Due to these factors, the fertilized egg entering the uterine cavity after fertilization cannot be implanted in a timely manner in the upper parts of the uterus, and this process occurs only when the fertilized egg has already descended into its lower parts.

The most common manifestation is recurrent bleeding from the genital tract. Bleeding can occur during various periods of pregnancy, starting from the earliest stages. However, most often they are observed already in the second half of pregnancy due to the formation of the lower segment of the uterus. In the last weeks of pregnancy, when uterine contractions become more intense, bleeding may increase.

The cause of bleeding is the repeated abruption of the placenta, which is unable to stretch following the stretching of the uterine wall as pregnancy progresses or labor begins. At the same time, it partially exfoliates, and bleeding occurs from the vessels of the uterus. The fetus does not lose blood. However, it is at risk of oxygen starvation, since the exfoliated part does not participate in gas exchange.

Provoking factors for bleeding during pregnancy can be: physical activity, sudden coughing, vaginal examination, sexual intercourse, increased intra-abdominal pressure during constipation, thermal procedures (hot bath, sauna).

When fully positioned, it often appears suddenly, without pain, and can be very abundant. Bleeding may stop, but after some time it may recur, or it may continue in the form of scanty discharge. In the last weeks of pregnancy, bleeding resumes and/or intensifies.

With incomplete presentation, bleeding may begin at the very end of pregnancy. However, more often this occurs at the beginning of labor. The severity of bleeding depends on the size of the attachment site. How more fabric, the earlier and stronger the bleeding begins.

Repeated bleeding during pregnancy complicated by pathology of the placenta in most cases leads to the development of anemia.

Also, pregnancy is often complicated by the threat of miscarriage, which is due to the same reasons as the occurrence of incorrect placement. Premature birth most often occur in patients with complete attachment.

Pregnant women with pathology are characterized by the presence of decreased blood pressure, which occurs in 25%-34% of observations.

Preeclampsia (nephropathy, late toxicosis) is also no exception for pregnant women with this diagnosis. This complication, occurring against the background of dysfunction of a number of organs and systems, as well as with the phenomena of blood clotting disorders, significantly worsens the nature of repeated bleeding.

An abnormality of the placenta is often accompanied by a lack of oxygen for the fetus and a delay in its development. The exfoliated part is switched off from the general circulatory system and does not participate in gas exchange. With a pathological location, an abnormal or pelvic position of the fetus (oblique, transverse) is often formed, which in turn is accompanied by certain complications.

In obstetric practice, the term “placental migration” has become widespread, which, in fact, does not reflect the real essence of what is happening. A change in its location is carried out due to changes in the structure of the lower segment of the uterus during pregnancy and the direction of growth towards better blood supply to areas of the uterine wall (towards the fundus of the uterus) compared to its lower sections. A more favorable prognosis in terms of migration is noted when it is located on the anterior wall of the uterus. Typically, the “migration” process takes place over 6-10 weeks and is completed by the middle of 33-34 weeks of pregnancy.

Diagnostics

Identifying anomalous placement is not particularly difficult. Its presence may be indicated by a pregnant woman’s complaints of bleeding. In this case, repeated bleeding in the second half of pregnancy is usually associated with complete attachment. Bleeding at the end of pregnancy or at the beginning of labor - with incomplete.

If there is bleeding, you should carefully examine the walls of the vagina and cervix using speculum to exclude trauma or pathology of the cervix, which may also be accompanied by the presence of bleeding.

A vaginal examination of a pregnant woman also easily reveals clear diagnostic signs indicating malposition. However, such a study must be performed as carefully as possible, in compliance with all the necessary rules to prevent possible bleeding.

Currently, the most objective and safe method diagnosis of presentation is ultrasonography(ultrasound), which allows you to establish the fact and type of deviation (complete, incomplete), determine the size, structure and area of ​​the place, assess the degree of detachment, and also get an accurate idea of ​​migration.

If an ultrasound reveals completeness, then a vaginal examination should not be performed at all. The criterion for a low location of the placenta in the third trimester of pregnancy (28 - 40 weeks) is the distance from the edge to the area of ​​the internal os of 5 cm or less. Its pathological placement is indicated by the detection of tissue in the area of ​​the internal pharynx.

About the nature of localization children's place in II and III trimesters pregnancy (up to 27 weeks) is judged by the ratio of the distance from the edge to the area of ​​the internal pharynx with the diameter (BDP) of the fetal head.

If an incorrect location is detected, a dynamic study should be carried out to monitor its “migration”. For these purposes, it is advisable to perform at least three echographic controls throughout pregnancy at 16, 24-26 and 34-36 weeks.

Ultrasound should be performed with moderate filling Bladder. Using ultrasound, it is also possible to determine the presence of blood accumulation (hematoma) between the placenta and the wall of the uterus during its detachment (in the event that there is no shedding of blood from the uterine cavity). If the area of ​​detachment occupies no more than 1/4 of the area, then the prognosis for the fetus is relatively favorable. If the hematoma occupies more than 1/3 of the area, then most often this leads to the death of the fetus.

Medical support for pregnant women

The nature of management and treatment of pregnant women depends on the severity of bleeding and the amount of blood loss.

In the first half of pregnancy, if there is no bleeding, the pregnant woman can be at home under outpatient monitoring, following a regimen that excludes the action of provoking factors that can cause bleeding (limitation of physical activity, sexual activity, stressful situations, etc.)

Observation and treatment for pregnancy over 24 weeks is carried out only in an obstetric hospital.

Treatment aimed at continuing pregnancy up to 37–38 weeks is possible if the bleeding is not heavy and the general condition of the pregnant woman and fetus is satisfactory. Even despite the cessation of bleeding from the genital tract, a pregnant woman under no circumstances can be discharged from the hospital before giving birth.

Management of pregnant women in an obstetric hospital includes: strict bed rest; the use of drugs that ensure optimization and normalization of contractile activity; treatment of anemia and deficiency.

Indications for emergency caesarean section, regardless of the stage of pregnancy, are: repeated bleeding; a combination of small blood losses with anemia and decreased blood pressure; immediate heavy blood loss; complete presentation and bleeding that has begun.

The operation is performed according to vital indications on the part of the mother, regardless of the duration of pregnancy and the condition of the fetus.

In the event that the pregnancy was carried to 37-38 weeks, depending on the current situation, the most suitable the best way delivery.

The absolute indication for elective caesarean section is complete attachment. Childbirth through the vaginal birth canal is impossible in this situation, since the blocking internal os does not allow part of the fetus (fetal head or pelvic end) to be inserted into the pelvic inlet. In addition, as the uterine contractions increase, the placenta will peel off more and more, and the bleeding will increase significantly.

In case of incomplete presentation and the presence of associated complications (pelvic position or abnormal attachment of the fetus, a scar on the uterus, multiple pregnancy, pronounced polyhydramnios, narrow pelvis, the age of the primigravida is over 30 years, etc.) a caesarean section should also be performed as planned.

If the above associated complications are absent and there is no bleeding, then you can wait until spontaneous labor begins, followed by early opening of the amniotic sac. If, after opening the amniotic sac, bleeding still begins, then it is necessary to resolve the issue of performing a cesarean section.

If, in case of incomplete presentation, bleeding occurs before the onset of labor, then the amniotic sac is opened. The necessity and expediency of this procedure is due to the fact that when the membranes are opened, the fetal head is inserted into the entrance to the pelvis and presses the detached part against the wall of the uterus and pelvis, which helps to stop further placental abruption and stop bleeding. If bleeding continues after opening of the membranes and/or the cervix is ​​immature, then a cesarean section is performed. If the bleeding stops, it is possible to conduct labor through the natural birth canal (if the obstetric situation is favorable).

Bleeding can begin in the early stages of labor, from the moment of the first contractions. In this case, early opening of the amniotic sac is also indicated.

Thus, management of childbirth with incomplete attachment through the natural birth canal is possible if: the bleeding stopped after opening the amniotic sac; the cervix is ​​mature; labor activity is good; there is a cephalic presentation of the fetus.

However, cesarean section is one of the most frequently chosen methods of delivery by obstetricians and is performed with a frequency of 70% -80% for this pathology.

Other typical complications during childbirth with placental anomalies are weakness of labor and insufficient oxygen supply to the fetus (fetal hypoxia). A mandatory condition for conducting childbirth through the natural birth canal is constant monitoring of the condition of the fetus and the contractile activity of the uterus.

After the birth of the child, bleeding may resume due to disruption of the separation process, since its site is located in the lower parts of the uterus, the contractility of which is reduced.

Heavy bleeding often occurs in the early postpartum period due to decreased uterine tone and damage to the extensive vascular network of the cervix.

Prevention

Prevention of anomalies consists of reducing the number of abortions, early detection and treatment of various inflammatory diseases organs of the reproductive system and hormonal disorders.

The placenta is an organ that forms in the female uterus during pregnancy and provides communication between the organisms of the child and the mother. Intrauterine development, excretion of metabolic products, nutrition and respiration of the fetus - all this is carried out through the placenta.

Externally, the placenta looks like a disc. Its thickness is 2-4 cm, diameter is 15-20 cm, and weight is 0.5-0.6 kg, which is approximately 1/6 of the weight of the fetus. If the pregnancy proceeds normally, then the placenta, as a rule, is located in the area of ​​the uterus, not adjacent to the pharynx. However, it often happens that the placenta is positioned incorrectly. One of these cases is marginal placenta previa, in which the lower part of this organ lies at the level of the edge of the internal os.

Regional placenta previa: causes

All existing factors that provoke an abnormal location of the placenta in the body of a pregnant woman are divided into two groups. The first group includes factors related directly to the specific structure of the fetal egg. The fact is that disruption of the trophoblast implantation process and the late manifestation of enzymatic actions leads to untimely implantation of the fertilized egg into the upper part of the uterus, and therefore a marginal placenta occurs. If it persists until the 24th week of pregnancy or longer, they speak of the presence of marginal placenta previa.

The second group includes factors that directly depend on the characteristics of the body and the health status of the expectant mother. These include:

• Pathological changes in the endometrium, contributing to disruption of the normal decidual reaction;
• Diseases such as endocervicitis or endometriosis;
• Uterine fibroids;
• Pregnancy with more than one fetus.

Diagnose marginal placenta possible using ultrasound.

Regional placenta previa: symptoms

The main manifestation of marginal placenta previa is bleeding that occurs during the third trimester of pregnancy, as well as during childbirth. These discharges are characterized by a sudden onset for no apparent reason, absence of accompanying pain and variable frequency. As a rule, it is not possible to determine their strength and duration in advance. In case of rupture of the marginal sinus of the placenta, presentation will be accompanied by heavy bleeding.

The diagnosis of “marginal placenta previa” requires regular medical supervision and timely implementation of all necessary tests. With such a common phenomenon as a decrease in hemoglobin, pregnant women are prescribed medicines, which contain iron. This will help avoid frequent and severe bleeding, as well as the rapid development of anemia.

Marginal placenta: consequences

What are the dangers of marginal placenta previa? As mentioned above, this deviation is fraught with bleeding, but this is not the only thing to be wary of. There is also a high probability that during the birth process the baby, by compressing the placenta, will block its own oxygen supply. In this regard, doctors usually insist that in case of marginal placenta previa, delivery is carried out by cesarean section.

Regional placenta previa: treatment

In order to raise the marginal placenta, they resort to either drug treatment, or to physical therapy in the form of electrophoresis with vitamins. In addition, experienced gynecologists recommend that women adhere to the following: simple rules during treatment of marginal placenta previa:

• Wear a special bandage;
• Stand in a knee-elbow position for several minutes, five times a day, making sure that the time intervals between approaches are equal;
• Avoid any physical activity;
• Do not have sexual intercourse.

Compliance with the recommendations of the attending physician in most cases helps to raise the placenta to the desired level, and therefore the risk of complications during childbirth, and with it the need for a caesarean section, disappears.54 votes)

Placenta previa during pregnancy is considered one of the serious complications during pregnancy and subsequent childbirth. The fact is that the situation when the placenta completely or partially covers the uterine os, and this is placenta previa, is irreparable - there is no way to correct this state of affairs with medication, although there is always a chance that it will displace on its own from the lower parts of the uterus.

The only symptoms that may indicate placenta previa during pregnancy are painless bleeding. They usually appear closer to the second half of pregnancy against the background of complete well-being.

Causes of placenta previa

Placenta previa is diagnosed using ultrasound, and the final diagnosis can be made after 24 weeks - before that there is a chance that the placenta will change position on its own. In addition to the fact that ultrasound determines the final diagnosis of placenta previa, this method also makes it possible to determine the variants of presentation, the size and area of ​​the placenta, and the degree of abruption.

The reasons for the occurrence of placenta previa during pregnancy can be changes in the mucous membrane of the inner wall of the uterus as a result of repeated abortions, inflammation or sexually transmitted infections, or previous complicated childbirth.

A predisposition to such pathology is more common in women with deformations of the uterine cavity, caused by congenital anomalies or acquired (for example, as a result of uterine fibroids).

The cause of placenta previa can even be diseases of the heart, liver or kidneys, accompanied by congestion in the pelvic organs (including the uterus).

In addition, placenta previa is three times more common in women who are giving birth more than once.

Depending on the location of the placenta, there is a low presentation (attachment) of the placenta, complete (central) or partial presentation (can be lateral or marginal).

Low placenta previa

At normal course During pregnancy, the placenta is located along the bottom or body of the uterus, along the anterior (less often posterior) wall with a transition to the lateral walls. Low placenta previa is characterized by a situation where the placenta is located in close proximity to the internal os of the cervix - at a distance of 6 cm or even less.

This pathology is most often determined in the second trimester of pregnancy during the next ultrasound. But at the same time, if low placenta previa was diagnosed during this period, there is a possibility that over time, as pregnancy progresses, the placenta will take a “normal position”.

Conventionally, this state of affairs is called “migration,” and the movement of the placenta is caused by stretching and stretching of the uterine tissue. So, as the fetus develops, the elastic tissues of the lower part of the uterus gradually rise upward. At the same time, some upward movement of the placenta occurs, due to which its location becomes normal. Therefore, if low position The placenta was discovered in the second trimester of pregnancy, there is a fairly high probability that it will move towards the end of pregnancy and the situation will normalize.

Regional placenta previa

Partial or incomplete placenta previa refers to its location in which the internal os of the uterus is blocked by the placenta, but not completely. One type of partial placenta previa is marginal placenta previa.

With the marginal location of the placenta, its lower edge is at the level of the edge of the internal os, while the outlet of the uterus is covered by approximately a third by placental tissue.

Usually, marginal placenta previa is diagnosed in the second trimester of pregnancy using ultrasound, against the background of complaints from the pregnant woman of constant bleeding. If marginal placenta previa has been determined, the woman requires careful medical observation and all necessary studies. Iron-containing drugs may be prescribed as necessary to avoid bleeding and the development of anemia due to a decrease in hemoglobin levels.

Complete placenta previa (central placenta previa)

Complete placenta previa is probably the most serious pathology associated with improper placement of the placenta. They speak of complete presentation when the placenta completely closes the internal os; during a vaginal examination, placental tissue is detected everywhere; the fetal membranes are not palpable. If, in addition, it is possible to establish that the center of the placenta is located at the level of the pharynx, a diagnosis of “central placenta previa” is made.

Partial placenta previa is diagnosed with a frequency of 70-80% of the total number of presentations. At the same time, complete presentation occurs in 20-30% of cases, and this, unfortunately, is not a small indicator.

With complete placenta previa, the woman, even in the absence of bleeding, must be sent to the hospital. Diagnosed central presentation is a serious pathology in which the pregnant woman should be provided with constant qualified medical supervision.

Treatment of placenta previa

If previa is detected, the doctor will decide on the treatment regimen and subsequent actions based on the specifics of placenta previa. But, be that as it may, in the case when a pregnant woman was diagnosed with placenta previa, she will need constant supervision by specialists.

If no bleeding is observed, the expectant mother may be allowed to be observed on an outpatient basis. At the same time, she needs to avoid stress - both physical and emotional, exclude sexual contact, sleep at least 8 hours a day and walk as much as possible. You will also need a special diet that involves consuming foods rich in iron, protein and vitamins. A diet is necessary to maximize the intake of useful substances into the pregnant woman’s body: with placenta previa, part of it does not participate in gas exchange, which can provoke. Meanwhile, the mother may experience anemia or anemia, which also becomes a consequence of placenta previa during pregnancy.

If, after 24 weeks, a pregnant woman experiences periodic bleeding, she will be asked to go to a hospital, where she can always receive emergency care in case of possible complications. In this case, doctors recommend inpatient observation until the end of pregnancy. If the bleeding is minor and the woman’s health has not worsened, resort to conservative methods Treatment: the pregnant woman is prescribed bed rest, complete rest, drugs that reduce the tone of the uterus and improve blood circulation. If found in expectant mother, she is prescribed drugs to increase hemoglobin levels, as well as drugs for general strengthening of the body.

Childbirth with placenta previa

Placenta previa during pregnancy is an indication for delivery by cesarean section; in the case of complete presentation, it is mandatory, since other methods of delivery are impossible. If the pregnancy has been preserved, a cesarean section is performed at 38-39 weeks.

With incomplete placenta previa, childbirth is possible, but it is associated with a certain risk. In addition, for natural birth in case of incomplete placenta previa, mandatory cessation of bleeding after opening of the membranes, a mature cervix, good labor and cephalic presentation of the fetus become mandatory conditions. In other cases, if childbirth proceeds naturally, there is a high risk of complete detachment of the placenta, which will lead to very heavy bleeding. And this is fraught with serious complications - even death for both mother and baby.

Especially for- Tatyana Argamakova

The slightest changes in well-being during pregnancy cause concern. As a rule, an immediate visit to the doctor follows with the hope of hearing that there is no reason to worry and this is a false alarm and the culprit is the suspiciousness inherent in all pregnant women. And suddenly it turns out that the fears were not in vain, and the diagnosis is “marginal placenta previa.” Instead of starting to panic and drive yourself crazy, you need to calm down, pull yourself together and figure out what it is and how dangerous it is.

The placenta is a unique and complex formation that appears in a woman’s body at the moment when a fertilized egg attaches to the wall of the uterus. Like any living organism, it goes through all stages of life: emergence, maturation and aging. The life of the little creature that has settled inside the mother’s tummy depends on it. Through it the baby breathes and receives nutrition. It’s not for nothing that it’s also called a “children’s place.” It serves as a kind of filter that supplies the fetus with oxygen and removes carbon dioxide and metabolic products back. Through it, antibodies pass from mother to baby, which provide immune protection. Without it, these same mother's antibodies would recognize the child as a foreign body and provoke rejection.

Active development of the placenta begins from the 9-10th week. On the 12th day, the child completely switches to placental nutrition and receives the official name “fetus”. And by the 15-16th week, it is, as a rule, a fully formed organ that will grow with the baby throughout the entire pregnancy. During scheduled ultrasound They monitor not only the development of the fetus, but also the condition, location and maturity of this vital “cake”.

In a normal pregnancy, the placenta is located on the back or front wall of the uterus at a distance from the uterine os. The most optimal and most common is the posterior attachment. With it, blood circulation occurs best, and the place itself is less susceptible to various injuries. But sometimes it is closer to the exit than it should be, or completely blocks it. This is called presentation, which, accordingly, can be complete (central) or incomplete.

The most dangerous thing is complete presentation. With it, the birth canal is completely blocked, as a result of which the child can be born exclusively by caesarean section.

With incomplete presentation, the placenta is in the lower segment and partially blocks the exit from the uterus to the cervix. There are two types: lateral presentation, in which the pharynx overlaps by two-thirds, and marginal, when the lower part of the placenta hangs over the outlet and covers it by no more than a third.

Regional placenta previa, in turn, occurs along the posterior and anterior wall, and has different prognoses depending on its location:

• On the front wall, on the one hand, is the most dangerous. With it, placental abruption often occurs. The reason for this is that placental tissue is not able to stretch as quickly as uterine tissue. Simply put, it does not have time to grow behind it, and the risk of detachment of the hanging edge increases. In addition, this is aggravated by the active movements of the child and the physical activity of the mother. But, on the other hand, with such a marginal presentation, there is a high chance that with the growth of the uterus, the placenta will rise to a safe distance.
• On the back wall occurs more often and poses less threat than in the previous case. This is due to the fact that this part bears less load. With it, there is every chance to safely endure pregnancy and give birth on your own.

In fact, in the world, 3-25% of pregnancies due to this pathology end tragically, or the baby is born with some abnormalities. Therefore, you need to take regional and other types seriously, regularly monitor the dynamics and follow all the doctor’s recommendations.

Causes of marginal placenta previa

One of the factors of this pathology is the peculiarity of the fertilized egg. After fertilization, the egg descends into the uterus and, with its villi, is attached to its wall in the upper part. This does not happen due to hormonal levels or the structure of the villi. The egg is unable to reach the bottom of the uterus and gets attached at the exit.

The main reason for the marginal attachment of the placenta is female body, or rather the condition of the mucous surface or endometrium of the main reproductive organ.

Factors that violate the integrity of the endometrium and cause presentation, including marginal presentation, are:

• inflammation, ;
• underdevelopment of the uterus;
• repeat pregnancy;
• endometriosis, endocervicitis;
• sexual infections;
• age over 35 years;
• scars after abortion or curettage;
• operations on the uterus;
• and other benign tumors;
• congenital pathologies;
• diseases of the cardiovascular system;
• diseases of the pelvic organs.

In repeat births, this anomaly is observed in 55% of cases, that is, in almost every second one. But in general, according to observations, a third of expectant mothers hear the diagnosis of regional location.

As a rule, they appear at the end of the second or third trimesters from 28 to 32 weeks. At this time, active growth of the uterus occurs. The placental tissue does not have time to stretch and marginal detachment occurs, which is accompanied by bleeding. The larger the area torn off, the more intense they are. This can happen for more early during or multiple pregnancy.

Any stress can cause detachment. This can happen with intra-abdominal pressure, which is often found in pregnant women, during passionate sexual intercourse, and even with a banal raising of the arms. An active baby can also contribute to this with his movements. Often the woman herself serves as a provocateur when she lifts weights or during excessively active physical activity. Bloody issues may also appear while visiting a sauna or taking a hot bath.

Bleeding begins suddenly, without pain, and also suddenly stops. However, it is impossible to predict when this will happen in next time and how abundant they will be.

This pathology is sometimes noticed already during the first planned ultrasound at 12-13 weeks or in the second trimester. As a rule, nothing bothers a woman and such a diagnosis sounds very unexpected to her. But most often, a pregnant woman herself comes to the doctor with complaints of spotting or bleeding. After a thorough examination, a conclusion is made about marginal or complete presentation, and the type of abnormal location and the degree of its danger to the fetus and expectant mother. Considering the complexity and risk of complications, in most cases the woman is recommended to go to the hospital to monitor her condition and complete examination.

What complications can arise with marginal placenta previa?

Due to the fact that when the placenta is separated during the marginal placement, the vessels are damaged, the child does not receive the necessary nutrition and oxygen. This is called fetal hypoxia. It threatens developmental delays and such consequences for mother and child as:

• incorrect positioning of the fetus;
• -low hemoglobin level - due to lack of iron in the body;
• hypotension and, as a consequence, weakness and fainting;
• excessive bleeding during childbirth.
• risk of miscarriage;

First of all, it is complete physical and psychological peace. Not all mothers manage to achieve this at home. Not everyone can afford not to go to work. And this is where the greatest emotional stress occurs. When there is an urgent recommendation to go into confinement, most immediately fall into a panic with thoughts about who will work instead of me, as well as wash and clean. Believe me, the world will not stop without you. Your main task is to this moment– this is not about submitting an accounting report or walking your beloved dog, but about carrying and giving birth to a healthy, long-awaited baby.

Mommy is prescribed strict bed rest, an iron-rich diet and, if necessary, medications that improve blood circulation, reduce uterine tone and —increase hemoglobin—. Up to 24 weeks, if there is no bleeding and the general condition is not bothering you, then you are allowed to be treated on an outpatient basis, strictly following the recommendations and protecting yourself as much as possible from household responsibilities. In difficult situations and later the mother may remain in the clinic until the birth, sometimes mainly in a supine position.

The placenta begins to migrate from the end of the second trimester along with the growing belly. Therefore, after the 26th week there is a high chance that marginal presentation will return to normal on its own.

Despite the complexity of the diagnosis, in some cases a woman is still allowed to give birth on her own, but only with a slight presentation. The main conditions for this are good labor, a mature cervix and the cephalic position of the fetus. When the cervix is ​​opened by more than 4 cm or a finger, the degree of location of the organ is determined and the amniotic sac is opened and further labor proceeds naturally. If bleeding does not stop after opening, an emergency caesarean section is performed. Most often, doctors prefer not to take risks and, in the case of a marginal location of any stage, perform delivery surgically. This is planned to happen at 38-39 weeks, when the baby is fully formed and ready to be born.

With strong or complete presentation

During natural childbirth, there is a high risk of placental abruption, which is fraught with heavy blood loss and other consequences for both the mother and the fetus, including death. Therefore, it is better not to take risks and entrust your life and the life of your baby to experienced specialists.

What precautions should pregnant women with marginal placenta previa take?

Such a diagnosis is not a death sentence, and with it it is quite possible to carry a pregnancy to term and become happy mom newborn miracle. To do this you need:

• do not miss scheduled visits to the clinic;
• seek help at the slightest deterioration in condition or the appearance of new symptoms, such as severe abdominal pain and so on;
• Call an ambulance immediately if there is bleeding;
• just in case, find in advance several people of your blood type who can become donors for you;
• forget about sex for a while;
• rest and walk more, unless prohibited by a doctor;
• sleep 8 hours;
• follow a diet and do not consume soda and foods that cause gas formation;
• protect yourself from negative emotions and stressful situations;
• follow all recommendations of the attending physician;
• exclude all physical activity: fitness, weight lifting and even cleaning the house or apartment;

And the most important thing is to enjoy your " interesting situation"and believe that everything will be fine!

Video

Watch the video from which you will learn what breech presentation is, what other types there are besides marginal, and how it affects the course of pregnancy.

Often a diagnosis announced by a doctor serves as an incentive to be more attentive to your health. Especially when you are responsible not only for your life, but also for small miracle that grows inside you.