Placenta previa 7 mm from the internal os. The position of the placenta in relation to the internal os

Update: October 2018

Placenta previa is rightfully considered one of the most formidable obstetric pathologies, which is observed in 0.2 - 0.6% of all pregnancies that ended in childbirth. What is the danger of this complication of pregnancy?

First of all, placenta previa is dangerous for bleeding, the intensity and duration of which cannot be predicted by any doctor. 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 gestation. With the help of the placenta, the connection between the mother and the fetus is carried out, the child receives nutrients through its blood vessels and gas exchange is carried out. If the pregnancy proceeds normally, the placenta is located in the region of the bottom of the uterus or in the region of its walls, as a rule, along the back wall, moving to the side walls (in these places, the blood supply to the muscle layer is more intense).

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

Choreon presentation types

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 in the gestation period up to 26 weeks.

The low location of the placenta is the most favorable option, bleeding during gestation and childbirth is rare, and the placenta itself is prone to so-called migration, that is, an increase in the distance between it and the internal pharynx. 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 isolated. In this case, the vessel/vessels are located in the shells, which are located in the region of the internal pharynx. This complication poses a threat to the fetus in case of violation of the integrity of the vessel.

Provoking factors

The reasons that cause placenta previa can be associated with both the state of the mother's body and the characteristics of the fetal egg. The main reason for the development of complications are dystrophic processes in the uterine mucosa. Then the fertilized egg is not able to infiltrate (implant) in 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 inferior second phase of the endometrium, in which it prepares for the implantation of a fertilized egg. Therefore, when forming a chorion, she is looking for the most favorable place that is well supplied with blood and is 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 “necessary” section of the uterus (in the bottom or along the back wall) and descends below, where it is introduced into the mucous membrane.

Symptoms of placenta previa

The course of pregnancy, complicated by placenta previa, is conventionally divided into "silent" and "pronounced" phases. The “silent” phase is almost asymptomatic. During the measurement of the abdomen, the height of the fundus of the uterus is more than normal, 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 take the 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 (Brexton-Gix contractions), which contributes to the stretching of the lower uterus (preparation for childbirth). The placenta, which does not have the ability to contract, “breaks away” from the uterine wall, and bleeding begins from its ruptured vessels.
• Secondly, the “deployment” of the lower segment of the uterus in the second half of pregnancy is intense, and the placenta does not have time to grow to the appropriate size and it begins to “migrate”, which also causes placental abruption and bleeding.

Characteristically, bleeding always begins suddenly, often against the background of absolute rest, for example, in a dream. When bleeding will occur and how intense it will be, it is impossible to predict.

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

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

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

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

Any minor factor can provoke the occurrence of bleeding:

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

Another difference in placenta previa is the progressive anemization of a woman (see). The volume of blood lost almost always does not correspond to the degree of anemia, which is much higher. During repeated spotting, the blood does not have time to regenerate, its volume remains low, which leads to low blood pressure, the development of DIC or hypovolemic shock.

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

Example from practice: In the antenatal clinic, a woman of 35 years old was observed - the second pregnancy, desired. At the first ultrasound at 12 weeks, she revealed a central placenta previa. An explanatory conversation was held with the pregnant woman, appropriate recommendations were given, but my colleague and I were observing with fear and expectation of bleeding. During the entire period of pregnancy, she had bleeding only once, in the period of 28-29 weeks, and then, not bleeding, but slight bloody discharge. Almost the entire pregnancy, the woman was on a sick leave, she was hospitalized in the pathology ward and at the threatened time and during the period of bloody discharge. The woman safely reached her term and at 36 weeks was sent to the maternity ward, where she successfully prepared for the upcoming planned caesarean section. But, as is often the case, on the holiday she began to bleed. Therefore, an operational team was immediately convened. The baby was born wonderful, even without signs). The afterbirth was separated without problems, the uterus was well reduced. 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 cost little blood.

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 history (in the past there were complicated births and / or the postpartum period, numerous abortions, diseases of the uterus and appendages, operations on the uterus, etc.), the course of a real pregnancy (often complicated by the threat of interruption) and external obstetric data research.

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

In the case of a pregnant woman who 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 probe. Inspection in the mirrors is carried out to determine the source of bleeding (from the cervix or varicose veins of the vagina).

The main condition that must be observed when examining with mirrors: the study is carried out against the backdrop of an expanded operating room and necessarily heated mirrors, so that in case of increased bleeding, the operation should not be started slowly.

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 with an overly filled bladder, therefore, when examining with an ultrasound probe, the bladder should be moderately filled.

Ultrasound examination allows not only to establish choreonal previa, but to determine its type, as well as the area of ​​the placenta. The timing of ultrasound 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 led and delivered

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

If the chorion previa was established in the first 16 weeks, there is no spotting and the general condition of the woman 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 baths, visits to 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 gestational age. Treatment of the described obstetric pathology includes:

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

Therapeutic and protective regimen includes:

• the appointment of sedatives (tincture of peony, motherwort or valerian)
• maximum restriction of physical activity (bed rest).
• Therapy of placental insufficiency prevents fetal growth retardation and consists in 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 preparations to increase hemoglobin (sorbifer-durule s, tardiferon and others).

Tocolytic therapy is carried out not only in case of an existing threat of termination of pregnancy or threatening premature birth, but also for the purpose of prevention, it is shown:

• antispasmodics (, magne-B6, magnesium sulfate)
• tocolytics (ginipral, partusisten), which are administered intravenously.
• in case of threatened or incipient preterm labor, prevention of respiratory disorders with corticosteroids and (dexamethasone, hydrocortisone) is mandatory for 2-3 days.

If bleeding occurs, the intensity of which threatens the life of a woman, regardless of the gestational age and the condition of the fetus (dead or non-viable), abdominal delivery is performed.

What to do and how to give birth with chorion presentation? doctors raise this question upon reaching the period of 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 independent labor). When opening the cervix 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. At the same time, the baby's head descends and presses against the entrance to the small pelvis, and, accordingly, presses the exfoliated placental lobes, which causes bleeding to stop. If the amniotomy has not produced an effect, the woman is delivered by the abdominal route.

A caesarean section is planned for those pregnant women who have been diagnosed with a complete presentation, or in the presence of an incomplete presentation and concomitant pathology (wrong position of the fetus, the pelvic end is present, age, a scar on the uterus, etc.). Moreover, the technique of the operation depends on which wall the placenta is located on. If the placenta is localized along the anterior wall, a corporal caesarean section is performed.

Complications

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

Example from practice: A multiparous woman was admitted to the obstetric department with complaints of bleeding within three hours from the birth canal. Diagnosis at admission: Pregnancy 32 weeks. Marginal placenta previa. Intrauterine growth retardation of the fetus of the 2nd degree (according to ultrasound). Uterine bleeding. The woman had no contractions, the fetal heartbeat was muffled, irregular. My colleague and I immediately called the dignity. aviation, since it is not yet clear how things could end other than a mandatory caesarean section. During the operation was extracted alive. Attempts to remove the placenta were unsuccessful (true placental accreta). The scope of the operation was expanded to hysterectomy (the uterus is removed along with the cervix). The woman was transferred to the intensive care unit, where she stayed 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 my mother was saved.

At placenta previa the internal pharynx can overlap completely and partially, depending on the type of presentation. So, with a central presentation, the internal pharynx is completely blocked, and with a lateral and marginal one and two thirds, respectively.
Regardless of the degree of throat overlap, pregnant women should adhere to the following rules:

1. Eliminate physical activity.

2. Avoid emotional stress.

3. Avoid sex.

4. Mandatory hospitalization for bleeding.

The placenta is the connection between the child and the mother, it is through it that the fetus receives nutrition and oxygen from the mother's body, giving, in turn, metabolic products.

The condition of the placenta directly determines how correctly the pregnancy will develop, and in some cases, the life of the fetus. Therefore, when placenta previa is diagnosed in a pregnant woman, doctors closely monitor her.

What is placenta previa

1. Presentation on the anterior wall. This is more likely not a diagnosis, but simply a statement of fact and it is not at all necessary that some complications will follow, although the risk of their development cannot be completely ruled out. Ideally, the placenta should be located on the back wall of the uterus, since it is in this place that the uterus is the least susceptible to changes during pregnancy.

The anterior wall is intensively stretched, thinned, which can lead to placental abruption or its further displacement to the uterine os. More about presentation on the anterior wall →

2. Lower placenta previa. Normally, the placenta is located at the bottom of the uterus. We know that the uterine fundus is on top, therefore, the pharynx is on the bottom. With a low location of the placenta (low placentation) - it is attached closer to the pharynx, not reaching it by less than 6 cm.

In this case, 2 scenarios are possible: either the placenta will drop even more, and it will be possible to talk about full or partial presentation, or it will rise up to the bottom along with the walls of the uterus increasing in size. With low placentation, as a rule, natural childbirth takes place without problems. More about lower presentation →

3. Incomplete (partial) placenta previa. There are two types of this presentation: lateral and marginal. With lateral presentation, the placenta covers the internal os (exit from the body of the uterus into the cervix) by 2/3. At the edge - by 1/3. Don't panic if you've been diagnosed with a partial presentation.

Very often, the placenta moves into its correct position before delivery. It is highly likely that childbirth is successful naturally, but everything is decided individually in each case. Learn more about partial presentation→

4. Full (central) presentation. The most severe case of abnormal location of the placenta. The placental tissue completely covers the uterine os, that is, the child simply cannot enter the birth canal. In addition, the pathology is also dangerous for the life of the mother, since the pharynx is the most extensible part of the uterus, which cannot be said about the placenta.

The uterus increases in size and there is a detachment of the placental tissue, which cannot be stretched as effectively and quickly. The integrity of the vessels is violated, which leads to severe bleeding, which, with complete placenta previa, can begin as early as the second trimester and disturb the woman until the very birth. Childbirth is only possible by caesarean section. More about full presentation →

Causes of placenta previa

The main reason is a violation of the integrity of the endometrium - the mucous layer of the uterus. A fertilized egg cannot attach itself in the most suitable place for this - at the bottom. It is there that the uterus stretches the least and can provide a high-quality metabolism between the mother and the fetus due to good blood supply.

However, due to diseases of the cardiovascular or other systems of the mother's body, fundus blood supply can be broken, and the ovum goes to look for a more suitable place for implantation.

Also, it will not be able to attach if there are scars and other endometrial damage. Usually, such deformities appear as a result of gynecological curettage, for example, during an abortion.

But the problem may not only be in the reproductive system of the mother. When underdevelopment fetal egg, it may not reach the bottom of the uterus, attaching immediately after entering it - in the area of ​​\u200b\u200bthe internal pharynx.

Symptoms and complications

The main symptom and complication at the same time is bleeding. It is caused by placental abruption: some area of ​​the placenta "breaks away" from the uterus, damaging the vessels. It is noteworthy that with low placentation, bleeding is internal, expressed as a hematoma. In all other cases, it is vaginal bleeding.

With partial placenta previa, bleeding begins in late pregnancy, with full - from the second trimester. In addition to the growth of the uterus itself, active physical activity, sex, gynecological examination and uterine tone can provoke bleeding.

As a result of regular, heavy bleeding, a woman may develop hypotension- stable low pressure, and anemia- low hemoglobin level. Therefore, pregnant women with presentation should be under the supervision of doctors and constantly undergo examinations. With bleeding and complete placenta previa, after 24 weeks, the woman is placed in a hospital, where she receives supportive treatment.

In some, fortunately rare, cases, placenta previa leads to fetal death.

Treatment of placenta previa

There is no medical treatment for the placenta. Doctors can not roll on this pathology. The only way out of the situation is to observe the pregnant woman, try to eliminate concomitant diseases, since any negative factor can worsen the condition, neutralize bleeding, relieve uterine tone.

Often, with placenta previa, especially central, complicated by bleeding, strict bed rest is prescribed in a hospital setting.

Childbirth with placenta previa

The main danger in childbirth is placenta previa because during contractions the placenta can completely exfoliate, and this will lead to acute fetal hypoxia, bleeding that threatens the life of the mother and the need for emergency operative delivery.

As mentioned above, natural childbirth with a low presentation is practically not a concern. With incomplete presentation - each case is considered individually. Central placenta previa is always a caesarean section at 38 weeks.

In addition, there is a possibility postpartum complications. namely the onset of bleeding. If the bleeding cannot be stopped, the uterus is removed, but these are isolated very severe cases when the life of the mother is at stake.

How to behave pregnant with placenta previa

An expectant mother diagnosed with placenta previa should protect herself from physical and emotional stress. It is necessary to exclude sudden movements, stress, overwork. Of course, this is not easy, given our rhythm of life, but the life of her child depends on it.

A woman needs good sleep, daytime rest, fresh air and emotional peace. It would be useful to revise your diet by adding iron-rich foods to it. For those who are concerned about frequent bleeding, this is a must. In addition, constipation should not be allowed. Read more about how to deal with constipation during pregnancy →

Placenta previa is a rather serious pathology that cannot but cause anxiety in the expectant mother. But she simply must pull herself together and carefully take care of herself and her baby. Moreover, today the vast majority of pregnancies complicated by presentation are easily tolerated thanks to medical care, and end in successful delivery.

Sources: http://mama66.ru/pregn/774

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placenta previa ( placenta praevia) - the location of the placenta in the lower segment of the uterus in the area of ​​​​the internal pharynx ( prae- before and via- on a way).

The placenta can cover the internal os in whole or in part.

The frequency of placenta previa depends on the gestational age. Before 24 weeks, placenta previa is more common (up to 28%). After 24 weeks, its frequency decreases to 18% and before childbirth - to 0.2-3.0%, as the placenta moves upward ("migration of the placenta").

The degree of placenta previa is determined by the dilatation of the cervix and may change throughout labor.

During pregnancy distinguish:

Complete placenta previa, when it completely covers the internal os (Fig. 24.1, a);

Incomplete (partial) presentation, when the internal pharynx is partially blocked or the placenta reaches it with its lower edge (Fig. 24.1, b, c);

Low placenta previa, when it is located at a distance of 7 cm or less from the internal pharynx (Fig. 24.1, d).

Rice. 24.1. Variants of placenta previa. A - complete; B - lateral (incomplete, partial); B - marginal (incomplete); G - low attachment of the placenta

Placenta previa during pregnancy is determined by ultrasound. According to transvaginal echography, four degrees of placenta previa are currently distinguished (Fig. 24.2):

Rice. 24.2. The degree of placenta previa according to ultrasound data (scheme) explanations in the text.

I degree - the placenta is located in the lower segment, its edge does not reach the internal pharynx, but is located at a distance of at least 3 cm from it;

II degree - the lower edge of the placenta reaches the internal os of the cervix, but does not overlap it;

III degree - the lower edge of the placenta overlaps the internal os, moving to the opposite part of the lower segment, its location on the anterior and posterior walls of the uterus is asymmetrical;

IV degree - the placenta is symmetrically located on the anterior and posterior walls of the uterus, blocking the internal os with its central part.

For a long time, the classification of the degree of placenta previa provided for its localization during childbirth with the opening of the cervix by 4 cm or more. At the same time, they singled out:

Central placenta previa ( placenta praevia centralis) - the internal pharynx is blocked by the placenta, the fetal membranes within the pharynx are not determined (see Fig. 24.1, a);

Lateral placenta previa ( placenta praevia lateralis) - part of the placenta lies within the internal pharynx and next to it are the fetal membranes, usually rough (Fig. 24.1, b);

Marginal placenta previa ( placenta praevia marginalis) - the lower edge of the placenta is located at the edges of the internal pharynx, only the fetal membranes are located in the pharyngeal region (Fig. 24.1, c).

Currently, placenta previa, both during pregnancy and during childbirth, is diagnosed using ultrasound. This allows you to deliver a pregnant woman before bleeding. In this regard, the above classification has lost its relevance, but for an idea of ​​the degree of placenta previa, it has a certain meaning.

In etiology placenta previa changes in the uterus and features of the trophoblast matter.

The uterine factor is associated with dystrophic changes in the uterine mucosa, as a result of which placentation conditions are violated. Chronic endometritis leads to dystrophic changes in the uterine mucosa; a significant number of births and abortions in history, especially with postpartum or postoperative endometritis; scars on the uterus after caesarean section or myomectomy, smoking.

Fetal factors contributing to placenta previa include a decrease in the proteolytic properties of the fetal egg, when its nidation in the upper sections of the uterus is impossible.

Under unfavorable conditions for nidation of the fetal egg, deviations in the development of the chorion are observed - atrophy of its villi occurs in the area decidua capsularis. At a possible location decidua capsularis a branched chorion is formed.

Due to reasons not fully known, in the early stages of pregnancy, a branched chorion is relatively often formed in the lower sections of the fetal egg. As the body of the uterus increases, the formation and stretching of the lower segment at the end of the II and III trimester, the placenta can move (migrate) up to 7-10 cm. At the time of placental displacement, small bleeding from the genital tract may occur.

With placenta previa, due to insufficient development of the uterine mucosa, a dense attachment of the placenta or its true increment is possible.

clinical picture. The main symptom of placenta previa is bleeding from the genital tract, which appears suddenly in full health, more often at the end of the II-III trimesters or with the appearance of the first contractions. With massive blood loss, hemorrhagic shock develops. The greater the degree of placenta previa, the earlier bleeding occurs. The blood flowing from the genital tract is bright scarlet. Bleeding is not accompanied by pain. It often recurs, leading to anemia in pregnant women. Against the background of anemia, relatively small blood loss can contribute to the development of hemorrhagic shock.

Bleeding is caused by detachment of the placenta from the uterine wall during the formation of the lower segment, when there is a contraction of muscle fibers in the lower sections of the uterus. Since the placenta does not have the ability to contract, as a result of displacement relative to each other of the lower segment of the uterus and the placenta, its villi are torn off from the walls of the uterus, exposing the vessels of the placental site. In this case, maternal blood flows out (Fig. 24.3). Bleeding can stop only at the end of muscle contraction, vascular thrombosis and termination of placental abruption. If uterine contractions resume, bleeding occurs again.

The intensity of bleeding can be different, it depends on the number and diameter of damaged uterine vessels.

Blood from the vessels of the placental site flows through the genital tract without forming hematomas, so the uterus remains painless in all departments, its tone does not change.

With the onset of labor, one of the factors in the appearance of bleeding in placenta previa is the tension of the membranes in the lower pole of the fetal egg, which hold the edge of the placenta, and it does not follow the contraction of the lower uterine segment. The rupture of the membranes helps to eliminate their tension, the placenta moves along with the lower segment, and bleeding can stop. An additional factor in stopping bleeding with incomplete placenta previa may be its pressing by the fetal head descending into the pelvis. With complete placenta previa, a spontaneous stop of bleeding is impossible, since the placenta continues to exfoliate from the uterine wall as the cervix smoothes.

The general condition of a pregnant woman with placenta previa is determined by the amount of blood loss. It is necessary to take into account the blood that can accumulate in the vagina (up to 500 ml).

The condition of the fetus depends on the severity of anemia or hemorrhagic shock with blood loss. With heavy bleeding, acute hypoxia develops.

The course of pregnancy. When placenta previa is possible:

The threat of termination of pregnancy;

Iron-deficiency anemia;

Incorrect position and breech presentation of the fetus due to an obstacle to inserting the head to the entrance to the small pelvis;

Chronic hypoxia and fetal growth retardation as a result of placentation in the lower segment and relatively low blood flow in this part of the uterus.

Diagnostics. The main diagnostic method for both placenta previa and its variant is ultrasound. The most accurate method is transvaginal echography.

Vaginal examination with placenta previa is not recommended, as it can lead to further placental abruption, increasing bleeding. In the absence of the possibility of ultrasound, vaginal examination is carried out with extreme caution. During the study, spongy tissue is palpated between the presenting part and the fingers of the obstetrician. Vaginal examination is carried out with a deployed operating room, which allows an emergency caesarean section in case of heavy bleeding.

Management of pregnancy and childbirth with placenta previa, it is determined by the gestational age, the presence of blood discharge and their intensity.

InIItrimester pregnancy with placenta previa according to the results of ultrasound and in the absence of blood discharge, the patient is observed in the antenatal clinic. The examination algorithm does not differ from the generally accepted standard, with the exception of the additional determination of hemostasis indicators in the blood. Pregnant women are advised to exclude physical activity, travel, and sexual activity. Regularly (after 3-4 weeks) ultrasound should be performed to track the migration of the placenta.

When bleeding occurs, the woman is hospitalized. Further tactics are determined by the amount of blood loss and the localization of the placenta. With massive blood loss, a small caesarean section is performed; with minor bleeding - therapy aimed at maintaining pregnancy under the control of hemostasis. Treatment consists in the appointment of bed rest, the introduction of antispasmodics. Depending on the indicators of hemostasis, substitution (fresh frozen plasma), disaggregation (curantyl, trental) therapy or the use of drugs aimed at activating hemostasis and improving microcirculation (dicynone) is carried out. At the same time, antianemic therapy is carried out. Ultrasound control over the location of the placenta.

INIIItrimester pregnancy with placenta previa without blood discharge, the issue of hospitalization is decided individually. If the patient lives near the maternity hospital and can get to it in 5-10 minutes, then she can be observed by the doctors of the antenatal clinic until 32-33 weeks. If the place of residence of the pregnant woman is significantly removed from the medical institution, she must be hospitalized earlier.

With abundant bleeding, urgent delivery is indicated -

abdominal and caesarean section in the lower uterine segment, regardless of the gestational age.

In the absence of blood discharge, it is possible to prolong pregnancy up to 37-38 weeks, after which, with any variant of placenta previa, in order to prevent massive bleeding, a caesarean section is performed in a planned manner. During caesarean section, especially when the placenta is located on the anterior wall of the uterus, bleeding may increase up to massive, which is caused by a violation of the contractility of the lower segment, where the placental site is located. The cause of bleeding can also be the dense attachment or accretion of the placenta, which is often observed in this pathology.

When the placenta is located on the anterior wall, an experienced doctor can perform a caesarean section in the lower segment of the uterus. In this case, it is necessary to make an incision on the uterus and placenta and continue it to the side without exfoliating the placenta from the uterine wall. Quickly remove the fetus and subsequently separate the placenta from the uterine wall by hand.

A novice doctor can perform a corporal caesarean section to reduce blood loss.

If massive bleeding occurs during caesarean section, which is not stopped after suturing the incision on the uterus and introducing uterotonic drugs, ligation of the iliac arteries is necessary. In the absence of effect, one has to resort to extirpation of the uterus.

In the presence of an angiographic installation, embolization of the uterine arteries is performed immediately after the extraction of the fetus in order to prevent massive bleeding. It is especially useful for timely ultrasound diagnosis of placental rotation during pregnancy. If this is detected on the operating table, catheterization of the uterine arteries is performed before the abdominal surgery and after the fetus is removed -

their embolization. Embolization of the uterine arteries makes it possible to perform an organ-preserving operation in case of true increment (ingrowth) of the placenta: excise part of the lower segment and suture the defect, preserving the uterus. If vascular embolization is not possible, then during ingrowth, to reduce blood loss, the uterus should be extirpated without separating the placenta.

During operative delivery, the device for intraoperative autologous blood reinfusion collects blood for subsequent reinfusion.

With incomplete placenta previa, the absence of bleeding with the onset of labor, it is possible to conduct labor through the natural birth canal, opening the membranes in a timely manner, which prevents further placental abruption. The same is facilitated by the head descending into the pelvis, which presses the exposed area of ​​​​the placental site to the tissues of the uterus. As a result, the bleeding stops, and further childbirth takes place without complications. With weak contractions or with a moving head above the entrance to the pelvis after amniotomy, intravenous administration of oxytocin (5 IU per 500 ml of isotonic sodium chloride solution) is advisable. The appearance or increase in bleeding after opening the fetal bladder is an indication for operative delivery by caesarean section.

In case of incomplete presentation, absence of bleeding and premature birth, non-viable (developmental defects incompatible with life) or dead fetus after amniotomy and a movable head above the entrance to the small pelvis, it is possible to use Ivanov-Gauss skin-head forceps. In case of their ineffectiveness, a caesarean section is performed.

In the past, pedunculation of the fetus was used to stop abruption of the placenta when the cervix was not fully dilated (Brexton Hicks rotation). This complex and dangerous operation for the mother and fetus was designed for the fact that after turning the fetus on the leg, the buttocks would press the placenta against the tissues of the uterus, as a result of which the bleeding could stop.

With placenta previa in the early postoperative or postpartum period, uterine bleeding is possible due to:

Hypotension or atony of the lower uterine segment;

Partial tight attachment or ingrowth of the placenta;

Rupture of the cervix after childbirth through the natural birth canal.

To prevent violations of uterine contractility at the end of the second stage of labor or during cesarean section after the extraction of the fetus, uterotonic agents are administered: oxytocin or prostaglandin (enzaprost) intravenously for 3-4 hours.

After childbirth through the natural birth canal, the cervix must be examined in the mirrors, since placenta previa contributes to its rupture.

Regardless of the method of delivery, the presence of a neonatologist is necessary, since the fetus can be born in a state of asphyxia.

In view of the significant risk of developing purulent-inflammatory diseases in the postoperative period, the mother is shown intraoperative (after clamping the umbilical cord) prophylactic administration of broad-spectrum antibiotics to her, which is continued in the postoperative period (5-6 days).

But the diagnosis of "placenta previa" is not a reason for panic - it only means that the expectant mother needs to take care of herself and not neglect the doctor's recommendations.

In the normal course of pregnancy, the placenta (an organ that provides blood supply, and with it oxygen and nutrients to the fetus) is usually located in the bottom (upper part of the uterus) or on the walls of the uterus, more often along the back wall, with the transition to the side walls, those. in those areas where the walls of the uterus are best supplied with blood. On the anterior wall, the placenta is located somewhat less frequently, since the anterior wall of the uterus undergoes significantly more changes than the posterior one. In addition, the location of the placenta on the back wall protects it from accidental injury.

Placenta previa is a pathology in which the placenta is located in the lower sections of the uterus along any wall, partially or completely blocking the area of ​​\u200b\u200bthe internal pharynx - the area of ​​​​the exit from the uterus. If the placenta only partially covers the area of ​​​​the internal pharynx, then this is an incomplete presentation, which is noted with a frequency of 70-80% of the total number of presentations. If the placenta completely covers the area of ​​​​the internal os, then this is called complete placenta previa. This option occurs with a frequency of 20-30%.

There is also a low location of the placenta, when its edge is at a lower level than it should be in the norm, but does not cover the area of ​​\u200b\u200bthe internal pharynx.

Causes

The most common causes of the formation of a low location or placenta previa are pathological changes in the inner layer of the uterus (endometrium) due to inflammation, surgical interventions (curettage, caesarean section, removal of myoma nodes - nodes of a benign uterine tumor, etc.), multiple complicated births. In addition, violations of the attachment of the placenta may be due to:

• existing uterine fibroids;
• endometriosis (a disease in which the inner lining of the uterus - the endometrium - grows in uncharacteristic places, for example, in the muscle layer);
• underdevelopment of the uterus;
• isthmic-cervical insufficiency (a condition in which the cervix does not perform its obturator function, it opens slightly and the fetal egg is not held);
• inflammation of the cervix;
• multiple pregnancy.

Due to these factors, the fetal egg entering the uterine cavity after fertilization cannot be implanted in the upper sections of the uterus in a timely manner, and this process is carried out only when the fetal egg has already descended into its lower sections. It should be noted that placenta previa is more common in re-pregnant women than in primiparas.

How does placenta previa manifest itself?

The most common manifestation of placenta previa is recurrent bleeding from the genital tract. Bleeding can occur during various periods of pregnancy, starting from its earliest terms. However, most often they are observed in the second half of pregnancy. In the last weeks of pregnancy, when uterine contractions become more intense, bleeding may increase.

The cause of bleeding is the repetitive placental abruption, which is not able to stretch following the stretching of the uterine wall during the progression of pregnancy or the onset of labor. In a normal location, the placenta is located in areas of the uterus that are least stretched. In this case, the placenta partially exfoliates, and bleeding occurs from the vessels of the uterus. The fetus does not shed blood. However, he is threatened by oxygen starvation, since the exfoliated part of the placenta is not involved in gas exchange.

The provoking factors for the occurrence of bleeding in placenta previa or its low attachment can be: physical activity, a sharp coughing movement, vaginal examination, sexual intercourse, increased intra-abdominal pressure with constipation, thermal procedures (hot bath, sauna).

With complete placenta previa, bleeding often appears suddenly, i.e. without provoking factors, without pain, and can be very abundant. Bleeding may stop, but reappear after some time, or may continue in the form of scanty discharge. In the last weeks of pregnancy, bleeding resumes and / or increases.

With incomplete placenta previa, bleeding can begin at the very end of pregnancy, but more often this occurs at the beginning of labor. The amount of bleeding depends on the size of the placenta previa. The more placental tissue is present, the earlier and more bleeding begins.

Recurrent bleeding during pregnancy, complicated by placenta previa, in most cases leads to the development of anemia - a decrease in the amount of hemoglobin in the blood.

Pregnancy with placenta previa is often complicated by the threat of interruption; this is due to the same reasons as the occurrence of an incorrect location of the placenta. Preterm labor most often occurs in patients with complete placenta previa.

Pregnant women with placenta previa are characterized by low blood pressure, which occurs in 25-34% of cases,

The management of pregnant women in an obstetric hospital provides, if necessary, the use of drugs that ensure the elimination of the contractile activity of the uterus.

Preeclampsia (a complication of pregnancy characterized by disruption of all organs and systems of the expectant mother, deterioration of uteroplacental circulation, more often manifested by an increase in blood pressure, the appearance of protein in the urine, edema) is also no exception for pregnant women with placenta previa. This complication, which occurs against the background of dysfunction of a number of organs and systems, as well as with symptoms of blood clotting disorders, significantly worsens the nature of recurrent bleeding.

Placenta previa is often accompanied by fetal placental insufficiency (the fetus does not receive enough oxygen and nutrients) and fetal growth retardation. The exfoliated part of the placenta is switched off from the general system of the uteroplacental circulation and does not participate in gas exchange. With placenta previa, an incorrect position of the fetus (oblique, transverse) or breech presentation is often formed, which, in turn, are accompanied by certain complications.

What is "placental migration"

In obstetric practice, the term "placental migration" is widely rooted, which, in fact, does not reflect the real essence of what is happening. The change in the location of the placenta is carried out due to a change in the structure of the lower segment of the uterus during pregnancy and the direction of growth of the placenta towards a better blood supply to the sections of the uterine wall (towards the bottom of the uterus) compared to its lower sections. A more favorable prognosis in terms of placental migration is noted when it is located on the anterior wall of the uterus. Usually the process of "migration of the placenta" occurs within 6 weeks and is completed by 33~34 weeks of pregnancy.

Diagnostics

Identification of placenta previa is not particularly difficult. The presence of placenta previa may be indicated by complaints of a pregnant woman about bleeding. In this case, recurrent bleeding from the second half of pregnancy, as a rule, is associated with complete placenta previa. Bleeding at the end of pregnancy or at the beginning of labor is more often associated with incomplete placenta previa.

In the presence of bleeding, the doctor will carefully examine the walls of the vagina and cervix using mirrors to exclude trauma or pathology of the cervix, which may also be accompanied by the presence of spotting.

A vaginal examination of a pregnant woman also easily reveals clear diagnostic signs indicating an incorrect location of the placenta. Currently, the most objective and safest method for diagnosing placenta previa is ultrasound, which allows you to establish the very fact of placenta previa and the variant of placenta previa (complete, incomplete), determine the size, structure and area of ​​the placenta, assess the degree of detachment, and also obtain an accurate concept of placental migration.

If the ultrasound revealed a complete placenta previa, then a vaginal examination is not performed at all, since it can provoke bleeding. The criterion for the low location of the placenta in the III trimester of pregnancy (for a period of 28-40 weeks) is the distance from the edge of the placenta to the area of ​​​​the internal os 5 cm or less. Placenta previa is indicated by the presence of placental tissue in the area of ​​the internal os.

The nature of the location of the placenta in the II and III trimesters of pregnancy (up to 27 weeks) is judged by the ratio of the distance from the edge of the placenta to the area of ​​the internal os with the diameter of the fetal head.

If an incorrect location of the placenta is detected, a dynamic study is carried out to control its "migration". For these purposes, at least three echographic control (ultrasound) is required during pregnancy at 16, 24-26 and 34-36 weeks.

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

Features of pregnancy and childbirth

The nature of pregnancy in women with placenta previa depends on the severity of bleeding and the amount of blood loss.

If there are no spotting in the first half of pregnancy, then the pregnant woman can be at home under outpatient control in compliance with a regimen that excludes the action of provoking factors that can cause bleeding (restriction of physical activity, sexual activity, stressful situations, etc.).

Observation and treatment at a gestational age of more than 24 weeks is carried out only in an obstetric hospital in any case, even in the absence of spotting and normal health.

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

Management of pregnant women in an obstetric hospital includes:

• observance of strict bed rest;
• if necessary, the use of drugs that ensure the elimination of the contractile activity of the uterus;
• treatment of anemia (reduced amount of hemoglobin) and fetal placental insufficiency.

In the event that the pregnancy has been carried to 37-38 weeks and placenta previa persists, depending on the situation, the optimal method of delivery is chosen on an individual basis.

The absolute indication for elective caesarean section is complete placenta previa. Childbirth through the natural birth canal in this situation is impossible, since the placenta that overlaps the internal os does not allow the presenting part of the fetus (this may be the fetal head or pelvic end) to be inserted into the entrance to the pelvis. In addition, in the process of increasing uterine contractions, the placenta exfoliates more and more, and the bleeding increases significantly.

In case of incomplete placenta previa and in the presence of concomitant complications (breech presentation, abnormal position of the fetus, scar on the uterus, multiple pregnancy, severe polyhydramnios, narrow pelvis, age of the primiparous over 30 years old, etc.), a caesarean section is also performed in a planned manner.

If the above concomitant complications are absent and there is no spotting, then the doctor waits until the onset of independent labor and opens the fetal bladder. In the event that, after opening the fetal bladder, bleeding nevertheless began, the issue of performing a caesarean section is decided.

If, with incomplete placenta previa, bleeding occurs before the onset of labor, then the fetal bladder is also 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 exfoliated part of the placenta against the wall of the uterus and pelvis, which helps to stop further placental abruption and stop bleeding. If bleeding after opening the fetal bladder continues and / or the cervix is ​​immature, then a caesarean section is performed. In case of stopping bleeding in the absence of complications, it is possible to conduct labor through the natural birth canal.

Bleeding can begin in the early stages of the development of labor from the moment of the first contractions. In this case, the fetal bladder is also opened.

Thus, vaginal delivery with incomplete placenta previa is possible if:

• bleeding stopped after the opening of the fetal bladder;
• mature cervix;
• labor activity is good;
• there is a cephalic presentation of the fetus.

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

Other typical complications in childbirth with incomplete placenta previa are weakness of labor and insufficient supply of oxygen to the fetus (fetal hypoxia). A prerequisite for conducting labor through the natural birth canal is constant monitoring of the condition of the fetus and the contractile activity of the uterus; sensors are attached to the woman's stomach, which are connected to a device that records the fetal heartbeat and the presence of contractions, these parameters are recorded on a tape or projected onto a monitor.

After the birth of a child, bleeding may resume due to a violation of the process of separation of the placenta, since the placental site is located in the lower sections of the uterus, the contractility of which is reduced.

Abundant bleeding often occurs in the early postpartum period due to a decrease in uterine tone and damage to the extensive vasculature of the cervix.

Prevention of placenta previa is the rational use of contraceptives, the exclusion of abortion, the early detection and treatment of various inflammatory diseases of the reproductive system and hormonal disorders.

Placenta previa (placenta praevia) - the location of the placenta in the lower segment of the uterus in the area of ​​​​the internal pharynx or 3 cm higher (according to ultrasound). With previa, the placenta is in the path of the fetus being born ("prae" - "before", "via" - "on the way").

ICD-10 CODE
O44 Placenta previa.
O44.0 Placenta previa, specified as without bleeding. Low implantation of the placenta, specified as non-bleeding.
O44.1 Placenta previa with haemorrhage. Low attachment of the placenta without further indications or bleeding. Placenta previa (marginal, partial, complete) without additional indications or bleeding.

EPIDEMIOLOGY

In the III trimester, the frequency of placenta previa is 0.2-3.0%. Up to 22–24 weeks, placenta previa is observed more often. As pregnancy progresses and the uterus grows, the placenta moves upward, after which it is located 7-10 cm above the internal os. This process is sometimes referred to as "migration of the placenta".

CLASSIFICATION OF PLACENTA PRESENTATION

There are classifications of placenta previa during pregnancy and during childbirth. The degree of placenta previa may change as the uterus grows or the cervix dilates during childbirth.

During pregnancy there are:
complete presentation - the placenta completely covers the internal pharynx;
Incomplete (partial) presentation - the internal pharynx is partially blocked or the placenta reaches the bottom edge of it;
low presentation - the placenta is located at a distance of 7 cm or less from the internal pharynx.

The variant of placenta previa during pregnancy is determined using ultrasound. According to transvaginal echography, four degrees of placenta previa are currently distinguished:
I degree: the placenta is located in the lower segment, the edge of the placenta reaches the internal os, but is located at a distance of at least 3 cm from it;
II degree: the lower edge of the placenta reaches the internal os of the cervix, but does not overlap it;
III degree: the lower edge of the placenta overlaps the internal os, moving to the opposite part of the lower
segment, while the location of the placenta on the anterior and posterior wall of the uterus is asymmetrical;
IV degree: the placenta is symmetrically located on the anterior and posterior walls of the uterus, covers the internal os with its central part.

For a long time, the classification of the degree of presentation included the determination of the localization of the placenta in childbirth with the opening of the uterine os by 4 cm or more. At the same time, they singled out:

Central placenta previa (placenta praevia centralis) - the internal pharynx is blocked by the placenta, the membranes within the pharynx are not determined;
lateral placenta previa (placenta praevia lateralis) - part of the placenta lies within the internal pharynx and next to it are the fetal membranes, usually rough;
Marginal placenta previa (placenta praevia marginalis) - the lower edge of the placenta is located at the edge of the internal pharynx, only the fetal membranes are located in the pharyngeal region.

The possibility of diagnosing presentation both during pregnancy and during childbirth with the help of ultrasound allows delivery before the onset of bleeding. In this regard, the last classification has lost its relevance, however, for a virtual representation of the degree of placenta previa, it has a certain meaning.

ETIOLOGY (CAUSES) OF PLACENTA PRESENTATION

Among the causes of placenta previa, two factors are distinguished: uterine and fetal.

The uterine factor is associated with degenerative changes in the uterine mucosa, resulting in a violation of the conditions of placentation. Chronic endometritis leads to dystrophic changes in the uterine mucosa; a significant number of births and abortions in history, especially with the development of postpartum or postoperative endometritis; the presence of scars on the uterus after CS or conservative myomectomy, smoking.

Fetal factors contributing to placenta previa include a decrease in the proteolytic properties of the fetal egg, when nidation in the upper uterus is impossible. Under unfavorable conditions for nidation of the fetal egg, deviations in the development of the chorion are observed - atrophy of the villi in the decidua capsularis region. At the site of the possible location of the decidua capsularis, a branched chorion is formed.

In the early stages of pregnancy, the formation of a branched chorion in the lower sections of the fetal egg quite often occurs. As the body of the uterus increases, the formation and stretching of the lower segment at the end of the II and III trimester, the placenta can shift, as if “migrating” up to 7–10 cm. At the time of placental displacement, a small amount of blood discharge from the genital tract may appear.

With placenta previa, due to insufficient development of the uterine mucosa in the lower segment, a dense attachment of the placenta or a true increment is possible.

CLINICAL PICTURE (SYMPTOMS) OF PLACENTA PRESENTATION

The main symptom of placenta previa is bleeding from the genital tract, which occurs suddenly in full health, more often at the end of the II-III trimester or with the appearance of the first contractions. Accordingly, blood loss is possible symptoms of hemorrhagic shock. The greater the degree of placenta previa, the earlier bleeding occurs. The blood flowing from the genital tract is bright scarlet. Bleeding is not accompanied by pain; often recurs, leading to anemia in pregnant women. Against the background of anemia, even a small blood loss can contribute to the development of hemorrhagic shock.

During the formation of the lower segment, there is a contraction of muscle fibers in the lower sections of the uterus.

Since the placenta does not have the ability to contract, as a result of the displacement of two surfaces relative to each other - the area of ​​the lower segment and the area of ​​the placenta - part of the latter exfoliates from the walls of the uterus, exposing the vessels of the placental site; the blood flowing out at the same time is maternal. Bleeding can stop only at the end of muscle contraction, vascular thrombosis and termination of placental abruption. If uterine contractions resume, bleeding occurs again. The intensity of bleeding varies from massive to slight, depending on the number and diameter of damaged uterine vessels. Blood from the vessels of the placental site flows through the genital tract without forming hematomas, so the uterus is painless in all departments and does not change its tone.

In childbirth, one of the factors in the appearance of bleeding in placenta previa is the tension of the membranes in the lower pole of the fetal egg, which hold the edge of the placenta that does not follow the contraction of the lower uterine segment.

The rupture of the membranes stops the tension, the placenta moves with the lower segment, the bleeding can stop. An additional factor in stopping bleeding with incomplete presentation may be the pressing of the placenta by the fetal head descending into the pelvis. With complete placenta previa, a spontaneous stop of bleeding is impossible, since the placenta continues to exfoliate from the uterine wall as the cervix smoothes.

The general condition of a pregnant woman with placenta previa depends on the amount of blood loss. In this case, it is necessary to take into account the blood accumulating in the vagina (up to 500 ml). The condition of the fetus depends on the severity of anemia or hemorrhagic shock with blood loss. With heavy bleeding, acute fetal hypoxia develops.

With placenta previa, the following complications of pregnancy occur:
Threat of interruption
· Iron-deficiency anemia;
Incorrect position and breech presentation of the fetus due to the presence of an obstacle to inserting the head into the small pelvis;
Chronic hypoxia and IGR due to placentation in the lower segment and relatively low blood flow in this part of the uterus.

DIAGNOSIS OF PLACENTA PRESENTATION DURING PREGNANCY

PHYSICAL EXAMINATION

Clinical signs of placenta previa include:
bleeding from the genital tract of a bright color with a painless uterus;
high standing of the presenting part of the fetus;
Incorrect positions or breech presentation of the fetus.

With placenta previa, a vaginal examination is undesirable, since placental abruption may occur, which increases bleeding. In the absence of the possibility of ultrasound, vaginal examination is carried out very carefully. During the study, spongy tissue is palpated between the presenting part and the fingers of the obstetrician.

Vaginal examination is carried out with a deployed operating room, which allows urgent CS to be performed in case of profuse bleeding.

INSTRUMENTAL STUDIES

Transvaginal echography is considered the most accurate method. It is extremely important to establish the presence or absence of a deep disorder of the chorionic villi in the endomyometrium (placenta adherens, placenta accreta), which are more often associated with placenta previa than with its normal location.

SCREENING

Ultrasound can detect pregnant women with placenta previa without clinical manifestations.

MANAGEMENT OF PREGNANCY AND DELIVERY WITH PLACENTA PRESENTATION

When placenta previa is established:
Presence or absence of bleeding
The intensity of bleeding
gestational age.

With abundant blood discharge, urgent delivery is indicated - ventricular surgery and CS, regardless of the gestational age.

With ultrasound diagnosis of placenta previa and the absence of blood discharge in the second trimester of pregnancy, the patient is observed in the antenatal clinic. The examination algorithm does not differ from the generally accepted standard, with the exception of an additional study of the hemostatic properties of blood.

TREATMENT OF PLACENTA PRESENTATION DURING PREGNANCY

INDICATIONS FOR HOSPITALIZATION

In the third trimester of pregnancy, in the presence of placenta previa and the absence of blood discharge, the issue of hospitalization is decided individually. If the patient lives near the maternity hospital and can get to it in 5–10 minutes, then it is possible for her to be observed by the doctors of the antenatal clinic until 32–33 weeks. If the place of residence of the pregnant woman is significantly removed from the medical institution, she should be hospitalized earlier.

Pregnancy can be prolonged up to 37–38 weeks, after which, in any variant of placenta previa, CS is routinely performed to prevent massive bleeding.

NON-DRUG TREATMENT

With incomplete placenta previa, the absence of bleeding at the time of the onset of labor, as an exception, it is possible to conduct labor through the natural birth canal. The opening of the membranes prevents further detachment of the placenta by the head descending into the pelvis. The head presses the exposed area of ​​the placental

platforms to the pelvic bones, bleeding stops, then childbirth proceeds without complications. With weak contractions or with a moving head above the entrance to the pelvis after amniotomy, intravenous administration of oxytocin is advisable.

With the appearance or intensification of bleeding after opening the fetal bladder, operative delivery is indicated.

In case of incomplete presentation, absence of bleeding and premature birth, non-viable (developmental defects incompatible with life) or dead fetus after amniotomy and moving over the entrance to the small pelvic head, it is possible to use Ivanov-Gauss skin-head forceps. If the intervention is ineffective, a CS is performed.

MEDICAL TREATMENT OF PREGNANT WOMEN WITH PLACENTA PRESENTATION

With minor bleeding, therapy is carried out aimed at maintaining pregnancy under the control of hemostasis in a hospital. Enter antispasmodics, b-agonists. If defects in hemostasis are detected, fresh frozen plasma, disaggregation drugs (dipyridamole, pentoxifylline), drugs aimed at activating hemostasis and improving microcirculation are administered. At the same time, antianemic therapy is carried out, ultrasound control of the location of the placenta is carried out.

SURGERY

During cesarean section, especially when the placenta is located on the anterior wall of the uterus, bleeding may increase, up to massive, which is caused by a violation of the contractility of the lower segment, where the placental site is located. The cause of bleeding can also be the dense attachment or accretion (ingrowth) of the placenta, often observed in this pathology.

When the placenta is located on the anterior wall, an experienced doctor can perform a caesarean section in the lower segment of the uterus. In this case, an incision is made with a scalpel on the uterus and placenta, it is continued to the side with scissors, without exfoliating the placenta from the uterine wall, the fetus is quickly removed and the placenta is separated by hand from the uterine wall.

A novice physician may perform a corporal caesarean section to reduce blood loss.

If massive bleeding occurs during a caesarean section, which does not stop after suturing the incision on the uterus and administering uterotonic drugs, tightening or mattress sutures are applied to the lower segment; in the absence of effect, ligation of the uterine, ovarian, and then internal iliac arteries is performed. If bleeding continues, the uterus is extirpated.

In the presence of an angiographic installation, embolization of the uterine arteries is carried out immediately after the extraction of the fetus in order to prevent massive bleeding. Intervention is advisable with timely ultrasound diagnosis of placenta accreta. In this case, catheterization of the uterine arteries is carried out on the operating table before transection, and after the extraction of the fetus, their embolization is carried out. Subsequently, you can either excise a part of the lower segment, or flash the surface of the uterus, where there was an accreta of the placenta. If vascular embolization is not possible during ingrowth, extirpation of the uterus is performed to reduce blood loss without separation of the placenta.

During operative delivery, in the presence of the "Cell saver" apparatus, blood is collected for subsequent reinfusion. At the same time, infusion-transfusion therapy is carried out (see the section "Hemorrhagic shock").

During CS, especially when the placenta is located on the anterior wall of the uterus, bleeding may increase, up to massive, due to a violation of the contractility of the lower segment, where the placental site is located. The cause of bleeding may also be a dense attachment or accretion (ingrowth) of the placenta.

With placenta previa in the early postoperative or postpartum period, uterine bleeding is possible due to hypotension or atony of the lower uterine segment or rupture of the cervix after childbirth through the natural birth canal. To prevent violations of the contractility of the uterus at the end of the second stage of labor or during CS after the extraction of the fetus, uterotonic agents are administered: oxytocin or PG (dinoprostone, dinoprost) intravenously for 3-4 hours.

It is mandatory to examine the cervix with the help of mirrors after childbirth through the natural birth canal, since placenta previa is often accompanied by ruptures.

In view of the high risk of developing purulent-inflammatory diseases in the postoperative period, intraoperative (after clamping the umbilical cord) prophylactic administration of broad-spectrum antibiotics is indicated, which continues in the postoperative period.

INDICATIONS FOR CONSULTATION OF OTHER SPECIALISTS

Regardless of the method of delivery, the presence of a neonatologist is necessary, since the child may be born in a state of asphyxia.

PREVENTION OF PLACENTA PRESENTATION

Since placenta previa occurs more often in multiparous women with intrauterine interventions in history, reducing the number of abortions, unjustified conservative myomectomy, and the frequency of CS due to the rational management of labor will help reduce the incidence of improper placental attachment.

INFORMATION FOR THE PATIENT

At home, a pregnant woman must observe a certain regimen (exclude physical activity, travel, sexual activity). It is necessary to regularly (every 3-4 weeks) conduct ultrasound in order to trace the migration of the placenta.

The pregnant woman and her relatives should know to which medical institution the pregnant woman should be urgently transported when bleeding occurs, especially massive.

The placenta is an important organ, the state of which plays an important role in the course of pregnancy and its outcome. The key point is the place of attachment. After all, the higher the location, the more favorable the pregnancy will be. The ideal option is the placenta on the back wall. In this case, the fetus develops and grows normally. This arrangement is good in that there is sufficient blood supply, and the placenta is protected from injury. Pregnancy in this case will proceed with the least risk of possible complications.

There is another opinion, according to which it is important not where the placenta is attached, but at what distance from the internal pharynx is the so-called "baby place". Each case should be considered individually.

The placenta is formed during pregnancy in order to provide nutrition to the fetus. She is a temporary body, which can be called a link between mother and child. Thanks to the placenta, the fetus receives all the necessary nutrients, as well as oxygen. The lungs of the baby are not yet functioning, and nature has come up with a simple method of life support.

Attachment of the placenta matters - there are several options. The most optimal of them is along the back wall, at the bottom of the uterus.

The more the pregnancy progresses, the more the walls stretch, and the process is uneven. The front is more stretchable, and the back has no elasticity. Thanks to this fact, the fetus is well supported and protected.

It is still unknown why the placenta attaches along the back wall and closer to the bottom of the uterus. But there are a few guesses:

• This area is equipped with a large number of vessels, the temperature is kept there, which is higher than anywhere else.
• Nearby is the exit from the fallopian tubes. The egg cannot move on its own, so it remains where it was brought by contractions of the fallopian tubes.
• Inside it itself are those mechanisms that are responsible for choosing a place for fastening.

The advantages of this location

It is easy for obstetricians to control the gestation process if the placenta is located on the back wall of the uterus - the fetus is available for palpation, ultrasound and a stethoscope. Even if there are some physical effects on this area, the amniotic fluid will soften them.

There are several points according to which it is proved that the placenta on the back of the uterus is the best option:

• Provides immobility of the placenta. The back wall can remain dense for a long time, little subject to change. It slightly increases in size, which reduces the load on the placenta.
• The risk of injury is reduced. If the localization of the placenta is along the back wall, then we can talk about less exposure to external factors, the baby's tremors.
• Reduces the risk of placenta previa. Very often in the early stages of pregnancy with the help of ultrasound, posterior placenta previa is detected. She gradually rises up, takes a normal position. When attachment occurs to the front wall, this process does not exist.
• Reduces the risk of premature detachment.
• Reduces the likelihood of placenta accreta and tight attachment. This item applies only to cases where a woman had to go through surgery with a scar on the front wall. If during pregnancy it is found that the placenta is attached there, there is a risk of true increment.

In all respects, the location of the placenta on the back wall is better than on the front. Indeed, in the second case, it may not have time to respond to changes, the formation of hematomas is possible. These 2-3 cm thickenings make it difficult to listen to the fetal heartbeat, the woman later begins to feel movements.

Condition features

It happens that the placenta is located low on the back wall. The doctor understands that its edge lags behind the internal pharynx by less than 6 cm. The reasons for this condition are frequent pregnancies, the presence of abortions, and inflammatory diseases of the endometrium of an infectious nature. A dangerous diagnosis is posterior placenta previa. In this case, the distance between its edge and the internal os is less than 6 cm. Because of this, there is a risk of premature detachment of the placenta. As a result of this condition, profuse bleeding occurs.

Women who have a low placenta should undergo ultrasound at certain times. Sometimes this is needed more often than during the normal course of pregnancy. If the diagnosis is confirmed for a period of 36 weeks, hospitalization, operative delivery is required. In this case, most cases end favorably.

There are factors that prevent the placenta from attaching in the optimal place:

• Defects in the area of ​​the egg membrane.
• The presence of fibroids in a woman, inflammatory, purulent phenomena, the presence of physical deformities of the uterus.
• An unproven factor is the effect of gravity during sleep.

More often, abnormal fastening is observed in women who have given birth.

It is important to remember that the posterior location of the placenta is not something that should be avoided all the recommendations of experts. An ultrasound scan once per trimester allows you to determine if a woman has a problem. If presentation is diagnosed, the doctor carefully plans the observation of the pregnant woman.

With an increase in the size of the uterus, presentation can pass on its own, but how the placenta behaves cannot be predicted or controlled. It is important that there is no tone in the area of ​​​​attachment of the fetus, because this increases the likelihood of detachment.