Danger of marginal placenta previa on the posterior or anterior wall: what is the bad diagnosis and what is the prognosis? What does marginal placenta previa mean, how it is dangerous and what it affects

26.08.2019

During pregnancy, a rather dangerous pathology associated with a violation of the normal location of the placenta can develop. In this case, carrying a baby can be complicated by the development of certain adverse symptoms. It should be considered in more detail what the marginal placenta previa means, as well as how it can be dangerous and what it affects during pregnancy.

What is it?

Doctors consider placenta previa as a pathology in which the place of initial attachment of the placental tissue is in the immediate vicinity of the internal uterine os. Normally, a fertilized egg attaches itself during implantation to an area in the upper part of the uterus called the fundus.

The location of the future chorion largely determines the initial location of the placental tissue. It is formed from fetal components, therefore it is in close proximity to it. If, for some reason, the fertilized egg is shifted to the internal uterine pharynx, then in this zone, placental tissue begins to form in the future. This leads to the development of pathology - placenta previa.

Doctors identify several clinical variants of this pathological condition. They determine them from how strongly the placental tissue comes into contact with the internal uterine pharynx. One of these clinical options is the marginal presentation. In this case, not the entire surface of the placental tissue, but only its individual sections, come into contact with the uterine pharynx with their edges.

Types of presentation

Causes of occurrence

A variety of causal factors can lead to the development of this pathology. Quite often, this pathological condition is preceded by chronic diseases of the reproductive organs. Women suffering from endometriosis, adnexitis, cervicitis and other diseases of the genital organs even before pregnancy are at increased risk for the development of this pathology.

The risk of developing marginal presentation is also quite high in women who have undergone surgery on the uterus or its appendages. Doctors note that scars on the uterus, which appeared as a result of an earlier cesarean section, can also contribute to the development of the marginal presentation.

The consequences of the transferred infectious diseases can also lead to the development of the marginal placenta previa. So, the coccal flora, which affects the internal uterine walls, leads to a change in the mucous membranes, which contributes to the violation of implantation. In this case, usually the fertilized egg descends to the lower parts of the uterus, where the endometrium is more functional.

Coccal flora

Congenital anomalies of the female genital organs can also lead to the development of this pathology. So, with a two-legged uterus, the risk of developing placenta previa slightly increases. The presence of polyps and myomatous nodes, which are located in the area of the uterine fundus, can also become a certain obstacle to the implantation of a fertilized egg in this area.

Not only pathologies on the part of a woman can lead to placenta previa. Some anomalies in the development of the chorion can also cause the development of this pathology. In some genetic pathologies, the trophoblast lacks certain enzymes necessary for implantation into the uterine wall. In this case, attachment to the uterus does not occur, as a result, the pregnancy is independently interrupted almost at the very beginning of its development.

Doctors note that the risk of developing marginal placenta previa is slightly higher in women who give birth to a second and subsequent babies. If, at the same time, the previous pregnancy ended with a cesarean section, then the likelihood of developing a marginal presentation increases.

Features of the course of pregnancy

The marginal presentation of the placenta can significantly complicate the process of carrying a baby. Such a pregnancy is usually characterized by a restless course, as well as the periodic appearance of adverse symptoms. It is worth noting that with extreme presentation, bearing is still somewhat calmer than with full presentation. In this case, the prognosis of the course of pregnancy is more favorable.

Adverse symptoms in this pathology usually appear after 16–20 weeks of pregnancy. By the third trimester, they may increase. In the very first weeks after fertilization, the expectant mother may not have any significant uncomfortable symptoms.

How to determine?

The location of the placental tissue is currently quite simple to determine. For this, doctors resort to prescribing ultrasound examinations. With marginal placenta previa, it is undesirable to carry out transvaginal ultrasound. In this case, the possibility of damage to the low-lying placental tissue is quite high. In this situation, it is better to choose a transabdominal ultrasound.

The localization of the placenta can also be determined through a routine vaginal examination. However, with marginal placenta previa, this technique is often not worth resorting to. If such an examination is carried out carelessly, the delicate tissue of the placenta can be damaged. That is why doctors give their preference to ultrasound techniques.

If, during the diagnosis, the regional presentation was determined, in this case, the following additional studies are assigned to the expectant mother. They are necessary in order to assess the dynamics of the course of a given pathology.

If the pathology was discovered quite early - at 12-16 weeks of gestation, then in such a situation the localization of the placental tissue may still change. The upward displacement of the placenta is called migration by doctors. It proceeds rather slowly and ends only by the 3rd trimester of pregnancy. That is why the localization of the placenta during its presentation is determined several times during the entire period of bearing the baby. Unfortunately, placental migration does not occur in all cases.

Migration of the placenta

Possible complications

The most striking symptom that usually makes a pregnant woman with a marginal placenta previa seek advice from an obstetrician-gynecologist is the appearance of blood from the genital tract. With this pathology, blood usually appears after lifting heavy objects or after intense physical exercise. The appearance of blood on underwear can only be an isolated symptom. In some cases, it is combined with the appearance of pain in the abdomen.

If a pregnant woman sees bleeding from the genital tract and at the same time her stomach hurts badly, then this means that she should not hesitate to seek medical help.

Bleeding from the genital tract with a very low position of the placenta can develop after sex. The possibility of having sex in the presence of such a pathology must be discussed with an obstetrician-gynecologist. Usually, nevertheless, doctors recommend that their patients with marginal placenta previa limit sex and prescribe sexual rest.

Many pregnant women confuse the pathology of the placenta and the umbilical cord. So, the marginal presentation of the placental tissue has nothing to do with the marginal discharge of the umbilical cord. Placenta previa is a pathology, and the marginal discharge of the umbilical cord is only a physiological feature of the course of a particular pregnancy.

An equally dangerous complication that can develop during pregnancy, complicated by marginal placenta previa, is the development of placental tissue detachment from the walls of the uterus. This pathology usually occurs as a consequence of traumatic influences. The more the placental tissue exfoliates from the uterine wall, the less favorable the prognosis for the course of pregnancy. To avoid the development of possible placental abruption, doctors make up a whole range of different recommendations. So, contraindications include intense sports, as well as running. A pregnant woman in whom pregnancy proceeds with the development of a marginal presentation is forbidden to lift too heavy objects. It is very important that the expectant mother rests more.

In addition to playing sports, a pregnant woman with a marginal placenta previa, the doctor may prohibit and visit the pool. Reviews of many women who had this pathology during pregnancy confirm this. With an extremely severe course of presentation, any physical activity can be limited, and in some cases even bed rest is prescribed.

Severe stress can also make the situation worse. The expectant mother should follow such recommendations strictly.

Preventing infection in the low-lying placenta is another challenge during complicated pregnancies. In this case, pathogenic organisms most often enter the uterine cavity from the external genital organs. In order to prevent such infection, a pregnant woman should carefully follow the rules of personal hygiene. The extreme position of the placenta relative to the uterine pharynx can also be dangerous for the developing fetus in the womb.

Violation of uteroplacental blood flow can lead to the development of placental insufficiency. In such a situation, the intensity of intrauterine development of the fetus is significantly reduced.

How is labor done?

Pregnancy with marginal placenta previa can have an extremely unpredictable prognosis. At any stage of carrying a baby, dangerous complications can arise that contribute to a change in the tactics initially chosen by doctors. So, in the event of severe bleeding or a threat to the life of the fetus, the doctor will be forced to resort to emergency surgical obstetrics.

Pregnant women with marginal placenta previa, as a rule, undergo a cesarean section. In this case, you can minimize the risk of developing dangerous complications that arise during spontaneous childbirth.

If, before giving birth, a woman was diagnosed with severe anemia, due to frequent previous bleeding from the genital tract, then in such a situation she will be prescribed iron-containing medications. For the fastest compensation of the general condition, such drugs are administered by injection. Even during a cesarean section in pregnancy accompanied by marginal placenta previa, there is a high risk of severe bleeding. During the operation, doctors must monitor the woman's pulse and blood pressure.

With the development of severe bleeding and massive blood loss, these indicators begin to decrease critically. In such a situation, doctors usually resort to parenteral administration of oxytocin or hemostatic agents. The main goal in carrying out such drug therapy is to preserve the life of the mother and her baby.

After the baby is born, doctors must assess his general condition. If necessary, the child undergoes a complex of resuscitation measures. Usually, they are required if the baby was born much earlier than the due date. Such medical manipulations are performed by a neonatologist, who is in the delivery room during childbirth. After giving birth, doctors must also monitor the condition of the woman in labor.

For information on the danger of the marginal placenta previa, see the next video.

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Questions and answers on: placenta previa on the back wall

2015-08-26 00:41:31

El asks:

Hello, the gestation period is 34 weeks (from the day of the last menstruation), height 164, weight at 13 weeks 60 kg, today 70 kg. When I was 33, I saw my doctor, she didn’t like that in 3 weeks I gained 3 kg, as well as my slight swelling of my feet, although I didn’t complain, there was no varicose veins. Before that, all tests (cardiogram, smears, blood, urine) and ultrasound are normal, pressure 110/80, the child, according to her, will be 3,600. the doctor could not listen to the heartbeat because of the battery dead in the device !!! - everything is normal ... But, they prescribed to drink 10 ml of Tivortin 3 times a day for 2 weeks, they just explained that this was to avoid oxygen starvation of the baby. I read the instructions, to be honest, I have no desire to accept it, tk. for the entire pregnancy there were only vitamins, and I felt good. In addition, it is not clear how my normal blood pressure will behave after taking it.
Today I decided to go for an ultrasound scan, the result is as follows:
longitudinal position of the fetus, head presentation, heartbeat rhythmically 135 beats / min, 4-chamber cut of the heart +, fetal movements +
BPR 86 mm, LZR - 104 mm, Cranial index: N, SJ N, DB-66 mm, SDGK N, Amniotic fluid normal, Vertical size of amniotic fluid AF 50 mm, placenta on the posterior wall, fundus of the uterus. The maturity of the placenta is 3, the thickness of the placenta is 38 mm, there are no pathological inclusions. The umbilical cord in the projection of the fetal neck is not visualized, the number of vessels is 3, visualized. At the time of examination, no congenital malformations were identified. The tone of the myometrium is normotonus.
Doppler: C / Do - 2.97 IR - 0.66

Fetal biophysical profile - 8 points
The activity of fetal movements - 2b.
Fetal muscle tone - 2b.
The amount of amniotic fluid is 2b.
Respiratory movements - 2b.

Conclusion: B 34 weeks, head presentation Premature maturation of the placenta.

I called my doctor, she prescribed Normoven in addition to Tivortin ... she said for the placenta ... CTG control once a week (I agree with CTG).

I am completely at a loss from such a diagnosis, I shoveled a bunch of conflicting information about these drugs, I have no desire to accept them and I'm scared for my daughter ... I would be grateful for the independent opinion of a specialist on my situation.

Answers Palyga Igor Evgenievich:

Hello Elya! Tivortin can be prescribed during pregnancy, it does not have any negative effect on the fetus and is prescribed for hypoxia. To be honest, I do not see any indications for prescribing drugs, but I have no right to virtually cancel or prescribe drugs. One thing I can say for sure - CTG is necessary to pass weekly. If hypoxia increases, you will be referred to a hospital.

2012-12-13 11:36:51

Christina asks:

Hello, I am turning to you for advice. The fact is that they cannot put me on the final term of pregnancy. I am 21 years old, my first pregnancy, at the time of conception I was 20 years old. There were no abortions.
The first day of the last menstruation is July 5, 2012, but I am sure that conception could not occur, since I had sex only after the 10th.
At the first ultrasound scan (October 17, 2012), a monthly period was set - 14 weeks 6 days, and according to the results of an ultrasound scan - 13 weeks 3 days.
On the second ultrasound scan (December 9, 2012), the monthly period is 22 weeks 3 days, but the results of the ultrasound scan:
BPR 48mm;
LZR 61mm;
OG 176mm;
Coolant 148mm;
DB / coolant * 100% = 21.6%
Thigh length right and left 32mm;
Shin length right and left 28mm;
The length of the humerus cn. sl. 30mm;
Forearm length cn. sl. 26mm;
The length of the nasal bone is 7.8 mm;
Neck fold thickness (up to 21 weeks) 4.5mm;
Heart rate 134 beats per minute;
The distance from the lower edge of the placenta to the int. throat 70mm;
Placenta thickness 24mm;
0 degree of maturity;
Amniotic index liquid 148mm;
Umbilical cord 3 vessels;
The length of the cervix is 36mm;
Localization of the placenta on the back wall;
Longitudinal position, breech presentation.
The spine is located. at 8 o'clock.
Half a girl.
The conclusion is 19-20 weeks of pregnancy, and according to the first ultrasound, it should be 21-22 weeks.
Could this be a delay in the internal development of the fetus?

Answers Gritsko Marta Igorevna:

That's right, in terms of time, it turns out 22 weeks, according to ultrasound data, 20 weeks. Were the results of the combined and triple tests normal? If so, then there is no need to worry, you need to assess the situation in dynamics. I don’t think this is intrauterine growth retardation. Pass the control SPL in a month.

2012-07-04 05:08:12

Venus asks. :

Hello, Doctor. Help me please! Today we had an ultrasound scan for 32 weeks. Please decipher. Is everything okay with me? And the gender of the child did not say exactly, the girl said more than percent, so who will be?
Presentation: head presentation. Position: longitudinal.
SOG 149; SRU h / z 3s. BPR / OG: 81/291.
SJ 270.Db 61. PMP: 1773gr (32cm)
Amniotic fluid: 55mm.
Placenta localization: on the posterior wall.
Maturity grade: 1degree of maturity
Placenta thickness: 35mm.
Recommendations for ultrasound observation: entanglement around the neck.

Conclusion: Pregnancy 32 weeks. The rate of development of the fetus is posterior.

Answers Wild Nadezhda Ivanovna:

Who will be? There will be a child! I can't say the rest, because an inspection is needed. A very convincing request: if you can’t make out the doctor’s handwriting, then don’t come up with diagnoses for yourself, it’s better to ask. You will be answered, given an explanation, but do not write nonsense. What is written is within the normal range for such a period. I believe that the most important thing is for the baby to be healthy, and let the gender be a surprise on the day of birth.

2012-05-15 03:22:08

Elena asks:

Now the 17th week on the ultrasound, they said the marginal presentation of the lower edge reaches the area of the internal pharynx, at 27-28 weeks I have to fly by plane for 3.30 minutes, no more abnormalities there is no tone no neck 50 mm length closed throughout the pain no blood no placenta on the back wall, can I fly? Having taken all the sedative medications just in case Vikasol Noshpu Magne, in three hours of flight, can something happen? You need to fly very much. What do you think?

Answers Wild Nadezhda Ivanovna:

It is impossible to predict on the front. The marginal presentation of the placenta is dangerous - bleeding, and this can lead to the death of the child. In addition, bleeding during pregnancy is life-threatening for the woman herself. It is very massive and in a very short period of time, they may not have time to provide assistance. But, one feature is characteristic of the placenta: migration, i.e. it can rise, but not always. We need ultrasound control. The placenta, which is difficult to diagnose along the back wall, can be missed a lot (not everything is visible, technically) ... Travel and flights are undesirable during pregnancy, especially in the hot season, this is a big load on the immune system of a woman and a child. Please tell me where the sea will go from you, etc., is it really vital? Is it really possible to neglect your child and your health so much? ... After all, there is a pressure drop during takeoff and landing. And much more ... You don't even need placenta previa .... Believe me! Everything that does not happen, everything is for the better, then it is so necessary from above. Think hard.

2016-04-07 10:46:44

Olga asks:

Good day. Can you please tell me, I have pregnancy 2, (1 frozen at 8 weeks). The term is 21 weeks. For a period of 18 weeks, the doctor determined by ultrasound that my placenta is located on the back wall very low 5 mm before reaching the pharynx. I was assigned to bed rest. After 2 weeks, i.e. for a period of 20 weeks, I was given a complete placenta previa with a transition to the anterior wall by 9 mm. They were told to continue strict bed rest, which is likely to continue until delivery, because raising the placenta is unlikely to occur. I have such a question for you: do I really need to lie down all the time or are walks for about 20 minutes on the street allowed? The fact is that I have been in bed since 10 weeks (there was a hematoma). In total, I have been lying in a horizontal position for 2.5 months without going outside. And if I also have to lie for 4 months without going out into the fresh air, I don’t know how I can withstand it. thanks

Answers Wild Nadezhda Ivanovna:

If there is placenta previa, that is, there is a high probability of massive bleeding, in such situations the mother is saved, the child dies. Therefore, the choice is yours: a walk or a child. The placenta is capable of migrating, therefore - everything is possible, you need patience and a positive attitude.

2015-05-20 18:41:04

Elena asks:

Can you please tell me at 20 weeks put the full placenta previa completely overlaps the level of the internal pharynx with the transition to the back wall, the width of the internal pharynx is 2 mm at 21 weeks, the placenta is located on the anterior wall of the uterus, the lower edge overlaps the pharynx by 53 mm if there is hope that the placenta migrates? whether to go to the hospital?

Answers Bosyak Yulia Vasilievna:

Hello, Elena! You have two SPL reports with different descriptions during one (!) Week. My opinion is that one of the doctors described the situation incorrectly. I advise you to undergo a control ultrasound scan with another specialist in a week. With full placenta previa, complete rest and observation in the hospital is really shown. As the pregnancy progresses, the placenta may tighten, so don't worry.

2015-04-07 14:08:57

Maria asks:

Hello, please tell me the ultrasound + fetal bridging at week 21 showed placenta previa 3 degrees: "localization of the placenta along the anterior wall of the uterus reaches the internal pharynx with the transition to the back wall" the placenta is bilobate. The rest is normal, no discharge does not bother! dangerous and what is the threat ?? is there a possibility of raising the placenta ??

2015-02-22 12:26:36

Irina asks:

Good day! The first day of the last menstruation on October 3, 2014, there was bacterial vaginosis, they prescribed treatment, which I did not completely go through, because I found out on November 5 that I was pregnant, I took such drugs Gynekit-4 days (29.10; 31.10; 02.11; 04.11), darsil from 29.10 to 4.11, milagin (3 candles) from 29.10 to 31.10, terzhinan from 1.10 to 4.10. Now I am 20 weeks pregnant, I did an ultrasound on 10/21/14, the term was set at 6-7 weeks (central presentation, hypertonicity in the lower segment, everything else is normal), then ultrasound on 12/19/14 at 11-12 weeks (marginal presentation on the back wall, hypertonicity in the lower segment, portal space-1.4 mm, nasal bones-2.6), the next day donated blood for screening results are normal (free beta hgch-53.6, free beta hochmom-1.16, PAPP -2.11, PAPP MOM-1.26). Ultrasound on 01/19/15 (for the second screening) everything is normal (the placenta has risen), on 01.24. The blood for screening is also normal, the results of AFP-alpha-fetoprotein AF -1.09 MOM, hCG MOM-0.74, free estriol UE3-0.93 MOM. Second planned ultrasound on 02/18/15, too, everything is normal, everything is visualized, the only small tone is periodically (I am treating him)! For all the time, all the tests, routine and special screenings and ultrasounds, everything is normal, BUT I am still worried about the risk of teratogenic effects on the fetus, very much. Suspicious! Can you please tell me if it is possible in this case, like mine, with all normal research, the possibility of giving birth to a baby with deviations ?! Thank you very much in advance!

Presentation placenta(placenta praevia - lat.) is a term used in obstetrics, with the help of which various options for the location of an organ in the cervical region are indicated. This means that the placenta is located in the lower part of the uterus and blocks the birth canal. It is the location on the path of the nascent fetus that reflects the Latin designation for presentation - placenta praevia, where the word "praevia" consists of two: the first preposition "prae" and the second root "via". Prae means before, and via means path. Thus, the literal translation of the term placenta praevia means literally "the placenta located in the path of the fetus."

Placenta previa currently refers to the pathology of pregnancy, and at 37-40 weeks of gestation occurs in 0.2-3.0% of cases. At earlier stages of pregnancy, placenta previa is observed more often (up to 5-10% of cases), however, as the fetus grows and develops, the uterus stretches, and its child's place moves further from the cervical region. This process is called "placental migration" by obstetricians.

To understand the essence of the pathological location of the placenta, called presentation, it is necessary to imagine the structure of the uterus, which is conditionally subdivided into the body, fundus and cervix. The cervix is located in the lower part of the organ, and its outer part is lowered into the vagina. The top of the uterus, which is the horizontal platform directly opposite the cervix, is called the bottom. And the side walls located between the bottom and the cervix are called the body of the uterus.

The cervix is a kind of tightly compressed muscle tissue cylinder with an opening inside, which is called the cervical canal. If this cylinder is stretched in width, then the cervical canal will expand significantly, forming an opening with a diameter of 9 - 11 cm, through which the child can exit the uterus during labor. Outside of childbirth, the cervix is tightly collapsed, and the opening in it is very narrow. To visualize the physiological role of the cervix, mentally draw a bag tied with a string. It is the part tied with a rope that is the very tightly compressed cervix that keeps the contents of the bag from falling out. Now turn this bag upside down so that the part pulled together by the string is facing the floor. In this form, the bag completely repeats the location of the parts of the uterus and reflects the role of the cervix. The uterus in a woman's abdomen is located exactly like this: the bottom is at the top, and the cervix is at the bottom.

In childbirth, the cervix of the uterus opens (expands) under the action of contractions, as a result of which an opening is formed through which the child can pass. In relation to the image of a bag, the process of opening the cervix is equivalent to simply untying a string that tightens its opening. As a result of this "opening" of the bag, everything that is in it will fall out of it. But if you untie the opening of the bag and at the same time put some kind of obstacle in front of it, then the contents will remain inside, because they simply cannot fall out. Likewise, a child will not be able to be born if there is an obstacle in his path, at the site of the opening of the cervix. It is such an obstacle that the placenta, located in the cervical region, is. And such an arrangement of it, which interferes with the normal course of the generic act, is called placenta previa.

With placenta previa, a high mortality rate of newborns is recorded, which ranges from 7 to 25% of cases, depending on the technical equipment of the maternity hospital. High infant mortality in placenta previa is due to the relatively high incidence of preterm birth, placental insufficiency and abnormal position of the fetus in the uterus. In addition to high infant mortality, placenta previa can cause a formidable complication - bleeding in a woman, from which about 3% of pregnant women die. It is because of the danger of child and maternal mortality that placenta previa is classified as a pathology of pregnancy.

Types of placenta previa and their characteristics

Depending on the specific features of the location of the placenta in the cervical region, there are several types of presentation. Currently, there are two main classifications of placenta previa. The first is based on determining its location during pregnancy using transvaginal ultrasound (ultrasound). The second classification is based on determining the position of the placenta during childbirth when the cervix is dilated by 4 cm or more. It should be remembered that the degree and type of presentation may change with the growth of the uterus or with an increase in cervical dilatation.

Based on the data of transvaginal ultrasound performed during pregnancy, the following types of adherence of the placenta are distinguished:
1. Full presentation;
2. Incomplete presentation;
3. Low presentation (low position).

Complete placenta previa

Full placenta presentation (placenta praevia totalis - lat.). In this case, the placenta completely covers the inner opening of the cervix (internal os). This means that even if the cervix is fully opened, the child will not be able to enter the birth canal, since the placenta will block his way, completely blocking the exit from the uterus. Strictly speaking, giving birth in a natural way with full placenta previa is impossible. The only delivery option in this situation is a cesarean section. This location of the placenta is noted in 20 - 30% of the total number of cases of presentation, and is the most dangerous and unfavorable in terms of the risk of complications, child and maternal mortality.

Incomplete (partial) placenta previa

With incomplete (partial) presentation (placenta praevia partialis), the placenta overlaps the internal opening of the cervix only partially, leaving a small area free from its total diameter. Partial placenta previa can be compared to a plug that covers part of the tube's diameter, preventing water from moving as fast as possible. Also, incomplete presentation includes the presence of the lower part of the placenta at the very edge of the cervical opening. That is, the lowest edge of the placenta and the wall of the inner opening of the cervix are at the same level.

With incomplete placenta previa in a narrow part of the cervical lumen, the head of the child, as a rule, cannot pass, therefore, in the vast majority of cases, childbirth in a natural way is impossible. The frequency of occurrence of this type of presentation is from 35 to 55% of cases.

Low (inferior) placenta previa

In this situation, the placenta is located at a distance of 7 centimeters or less from the perimeter of the entrance to the cervical canal, but does not reach it. That is, the area of the internal os of the cervix (the entrance to the cervical canal) with low presentation is not captured and is not overlapped by a part of the placenta. Against the background of low placenta previa, natural childbirth is possible. This pathology option is the most favorable in terms of the risk of complications and pregnancy.

According to the results of ultrasound, more and more often in recent years, for clinical practice, obstetricians have resorted to determining not the type, but the degree of placenta previa during pregnancy, which are based on the amount of overlap of the internal opening of the cervix. Today, according to ultrasound, the following four degrees of placenta previa are distinguished:

I degree- the placenta is located in the area of the cervical opening, but its edge is at least 3 cm from the pharynx (conditionally corresponds to a low placenta previa);
II degree- the lower part of the placenta is located literally at the edge of the entrance to the cervical canal, but does not overlap it (conditionally corresponds to incomplete placenta previa);
III degree- the lower part of the placenta blocks the entrance to the cervical canal completely. In this case, most of the placenta is located on any one wall (front or back) of the uterus, and only a small area closes the entrance to the cervical canal (conditionally corresponds to full placenta presentation);
IV degree- the placenta is completely located on the lower segment of the uterus and blocks the entrance to the cervical canal with its central part. At the same time, the same parts of the placenta are located on the anterior and posterior walls of the uterus (conditionally corresponding to full placenta presentation).

The listed classifications reflect the options for placenta previa during pregnancy, determined by the results of ultrasound.

In addition, the so-called clinical classification of placenta previa has been used for a long time, based on determining its location in the process of childbirth when the cervix is dilated by 4 cm or more. On the basis of a vaginal examination during childbirth, the following types of placenta previa are distinguished:

Central presentation of the placenta (placenta praevia centralis);
Lateral presentation of the placenta (placenta praevia lateralis);
Regional presentation of the placenta (placenta praevia marginalis).

Central placenta previa

In this case, the entrance to the cervical canal from the side of the uterus is completely blocked by the placenta, when feeling its surface with a finger inserted into the vagina, the doctor cannot determine the fetal membranes. Natural childbirth with central placenta previa is impossible, and the only way to give birth to a child in such a situation is by cesarean section. Relatively speaking, central placenta previa, determined during vaginal examination during labor, corresponds to complete, as well as grade III or IV according to the results of ultrasound.

Lateral placenta previa

In this case, during the vaginal examination, the doctor determines the part of the placenta that closes the entrance to the cervical canal, and the rough membranes next to it. Lateral placenta previa, determined by vaginal examination, corresponds to incomplete (partial) or II-III degree according to the results of ultrasound.

Regional presentation of the placenta

During the vaginal examination, the doctor determines only the rough membranes of the fetus protruding into the lumen of the cervical canal, and the placenta is located at the very edge of the internal pharynx. Regional presentation of the placenta, determined by vaginal examination, corresponds to incomplete (partial) or I-II degree according to the results of ultrasound.

Posterior placenta previa (placenta previa on the back wall)

This condition is a special case of incomplete or low presentation, in which the main part of the placenta is attached to the back of the uterus.

Anterior placenta previa (placenta previa along the anterior wall)

This condition is also a special case of incomplete or low presentation, in which the main part of the placenta is attached to the anterior wall of the uterus. The attachment of the placenta to the anterior wall of the uterus is not a pathology, but reflects a variant of the norm.

In most cases, the anterior and posterior presentation of the placenta is determined by the results of an ultrasound scan up to 26 - 27 weeks of pregnancy, which can migrate within 6 - 10 weeks and come to a normal position by the time of delivery.

Placenta previa - causes

The placenta is formed on the part of the uterus where the ovum is attached. Therefore, if the egg is attached to the lower wall of the uterus, then the placenta will form in this part of the organ. The place for attachment is "selected" by the ovum, and it is looking for such a site of the uterus, which has the most favorable conditions for its survival (good thick endometrium, absence of neoplasms and scars, etc.). If the best endometrium, for some reason, is in the lower segment of the uterus, then the ovum will attach there, and subsequently this will lead to placenta previa.

The reasons for the attachment of the ovum in the lower segment of the uterus and the subsequent formation of placenta previa are due to various factors, which, depending on the original nature, can be divided into two large groups:
1. Uterine factors (depending on the woman);
2. Fetal factors (depending on the characteristics of the ovum).

Uterine factors- these are various pathological changes in the mucous membrane of the uterus (endometrium), formed during inflammatory diseases (endometritis, etc.) or intrauterine manipulations (abortion, diagnostic curettage, cesarean section, etc.). Fetal factors are a decrease in the activity of enzymes in the membranes of the ovum, which allow it to be implanted into the lining of the uterus. Due to the lack of enzyme activity, the ovum "slips" past the bottom and walls of the uterus and is implanted only in its lower part.

Currently, the following conditions are attributed to the uterine causes of placenta previa:

Any surgical interventions on the uterus in the past (abortion, cesarean section, removal of fibroids, etc.);
Childbirth with complications;
Abnormalities in the structure of the uterus;
Underdevelopment of the uterus;
Isthmic-cervical insufficiency;
Multiple pregnancies (twins, triplets, etc.);
Endocervicitis.

Due to the fact that most of the causes of placenta previa appear in women who have undergone any gynecological diseases, surgery or childbirth, this complication is observed in 2/3 of cases in re-pregnant women. That is, women who are pregnant for the first time account for only 1/3 of all cases of placenta previa.

For fruitful reasons placenta previa include the following factors:

Inflammatory diseases of the genital organs (adnexitis, salpingitis, hydrosalpinx, etc.);

Given the listed possible causes of placenta previa, the following women are at risk for the development of this pathology:

Burdened obstetric history (abortion, diagnostic curettage, difficult childbirth in the past);
Any surgical interventions on the uterus transferred in the past;
Neuro-endocrine dysregulation of menstrual function;
Underdevelopment of the genitals;
Inflammatory diseases of the genital organs;
Myoma of the uterus;
Endometriosis;
Pathology of the cervix.

Diagnosis of placenta previa

Diagnosis of placenta previa can be based on characteristic clinical manifestations or on the results of objective studies (ultrasound and bimanual vaginal examination). Signs of placenta previa are as follows:

Bloody discharge from the genital tract of a bright scarlet color with a completely painless and relaxed uterus;
High standing of the fundus of the uterus (the indicator is more than that which is characteristic for a given gestational age);
Abnormal position of the fetus in the uterus (breech presentation of the fetus or transverse position);
The noise of blood flow through the vessels of the placenta, clearly distinguishable by the doctor during auscultation (listening) of the lower segment of the uterus.

If a woman has any of the listed symptoms, then the doctor suspects placenta previa. In such a situation, a vaginal examination is not performed, since it can provoke bleeding and premature birth. To confirm the preliminary diagnosis of placenta previa, the gynecologist sends a pregnant woman to an ultrasound scan. Transvaginal ultrasound allows you to accurately determine whether a given woman has placenta previa, as well as to assess the degree of occlusion of the uterine pharynx, which is important for determining the tactics of further pregnancy management and choosing the method of delivery. Currently, it is ultrasound that is the main method for diagnosing placenta previa, due to its high information content and safety.

If it is impossible to do an ultrasound, then to confirm the diagnosis of placenta previa, the doctor makes a very careful, accurate and careful vaginal examination. When placenta previa with fingertips, the gynecologist feels the spongy tissue of the placenta and rough membranes.

If a woman does not have any clinical manifestations of placenta previa, that is, the pathology is asymptomatic, then it is detected during screening ultrasound studies, performed without fail at 12, 20 and 30 weeks of pregnancy.

Based on the ultrasound data, the doctor decides whether it is possible to perform a vaginal examination in this woman in the future. If placenta previa is complete, then a standard two-handed gynecological examination cannot be performed under any circumstances. With other types of presentation, you can only very carefully examine the woman through the vagina.

Ultrasound diagnostics

Ultrasound diagnostics of placenta previa is currently the most informative and safe method for detecting this pathology. Ultrasound also allows you to clarify the type of presentation (full or partial), measure the area and thickness of the placenta, determine its structure and identify areas of detachment, if any. To determine the various characteristics of the placenta, including presentation, ultrasound should be performed with a moderate filling of the bladder.

If placenta previa is detected, then periodically, with an interval of 1 to 3 weeks, an ultrasound scan is performed in order to determine the speed of its migration (movement along the walls of the uterus above). To determine the position of the placenta and assess the possibility of conducting natural childbirth, it is recommended to perform an ultrasound scan at the following stages of pregnancy - at 16, 24 - 25 and 34 - 36 weeks. However, if there is an opportunity and desire, then an ultrasound scan can be done weekly.

Placenta previa - symptoms

The main symptom of placenta previa is recurrent painless bleeding from the genital tract.

Bleeding with placenta previa

Bleeding with placenta previa can develop at various stages of gestation - from 12 weeks to the very birth, but most often they are noted in the second half of pregnancy due to severe stretching of the walls of the uterus. With placenta previa, bleeding up to 30 weeks is noted in 30% of pregnant women, at 32 - 35 weeks also in 30%, and in the remaining 30% of women, they appear after 35 weeks or at the beginning of labor. In general, with placenta previa, bleeding during pregnancy is observed in 34% of women, and during childbirth - in 66%. During the last 3 to 4 weeks of pregnancy, when the uterus contracts particularly strongly, bleeding may worsen.

Bleeding during placenta previa is due to its partial detachment, which occurs as the wall of the uterus stretches. When a small area of the placenta is detached, its vessels are exposed, from which bright scarlet blood flows.

Various factors can provoke bleeding during placenta previa, such as excessive physical exertion, severe cough, vaginal examination, sauna use, sexual intercourse, bowel movement with strong straining, etc.

Depending on the type of placenta previa, the following types of bleeding are distinguished:

Sudden, profuse and painless bleeding, often occurring at night, when a woman literally wakes up in a pool of blood, is characteristic of complete placenta previa. Such bleeding may stop as suddenly as it began, or it will continue in the form of a scanty discharge.
The onset of bleeding in the last days of pregnancy or in childbirth is characteristic of incomplete placenta previa.

The intensity of bleeding and the amount of blood loss does not depend on the degree of placenta previa. In addition, bleeding with placenta previa can be not only a symptom of pathology, but also become its complication, if it does not stop for a long time.

Given the repeated episodes of bleeding in placenta previa, pregnant women with this pathology almost always have severe anemia, a lack of circulating blood volume (BCC), and low blood pressure (hypotension). These nonspecific signs can also be considered symptoms of placenta previa.

Also, the following signs are considered indirect symptoms of placenta previa:

Wrong presentation of the fetus (oblique, transverse, gluteal);
High standing of the fundus of the uterus;
Listening to the murmur of blood in the vessels at the level of the lower segment of the uterus.

What threatens placenta previa - possible complications

Placenta previa can threaten the development of the following complications:

The threat of termination of pregnancy;
Iron-deficiency anemia;
Wrong position of the fetus in the uterus (oblique or transverse);
Breech or foot presentation of the fetus;
Chronic fetal hypoxia;
Delayed fetal development;
Placental insufficiency.

The threat of termination of pregnancy is due to periodically recurring episodes of detachment of the placenta, which provokes fetal hypoxia and bleeding. Full placenta previa most often ends in preterm labor.

Gestosis in placenta previa is due to the impossibility of a full-fledged second invasion of the trophoblast into the endometrium, since the mucous membrane in the lower segment of the uterus is not dense and thick enough for additional villi to enter it. That is, a violation of the normal growth of the placenta during its presentation provokes gestosis, which, in turn, increases the severity and increases the frequency of bleeding.

Fetoplacental insufficiency is due to the fact that the blood supply to the lower segment of the uterus is relatively low compared to the bottom or the body, as a result of which insufficient blood flows to the placenta. Poor blood flow results in insufficient oxygen and nutrients reaching the fetus and therefore not meeting its needs. Against the background of such a chronic deficiency of oxygen and nutrients, hypoxia and fetal growth retardation are formed.

Iron deficiency anemia is caused by recurring recurrent bleeding. Against the background of chronic blood loss in a woman, in addition to anemia, a deficiency of circulating blood volume (BCC) and coagulation factors is formed, which can lead to the development of disseminated intravascular coagulation syndrome and hypovolemic shock during childbirth.

The incorrect position of the child or his breech presentation is due to the fact that in the lower part of the uterus there is not enough free space to accommodate the head, since it was occupied by the placenta.

Placenta previa - principles of treatment

Unfortunately, there is currently no specific treatment that can change the place of attachment and the location of the placenta in the uterus. Therefore, therapy for placenta previa is aimed at stopping bleeding and maintaining pregnancy for as long as possible - ideally until the term of delivery.

With placenta previa throughout pregnancy, a woman must necessarily observe a protective regime aimed at eliminating various factors that can provoke bleeding. This means that a woman needs to limit physical activity, do not jump and drive on a shaky road, do not fly an airplane, do not have sex, avoid stress, do not lift weights, etc. In your free time, you should lie on your back, throwing your legs up, for example, on a wall, on a table, on the back of a sofa, etc. The "lying on your back with raised legs" position should be taken whenever possible, preferring to just sitting on a chair, in a chair, etc.

After 24 weeks, if bleeding is not abundant and stops spontaneously, a woman should receive conservative treatment aimed at maintaining pregnancy until 37 to 38 weeks. Placenta previa therapy consists of the following drugs:

Tocolytic and antispasmodic drugs that improve the stretching of the lower segment of the uterus (for example, Ginipral, No-shpa, Papaverine, etc.);
Iron preparations for the treatment of anemia (for example, Sorbifer Durules, Ferrum Lek, Tardiferon, Totema, etc.);
Preparations to improve the blood supply to the fetus (Ascorutin, Curantil, Vitamin E, folic acid, Trental, etc.).

The most common conservative treatment for placenta previa against the background of non-abundant bleeding consists of a combination of the following drugs:

Intramuscular injection of 20 - 25% magnesium, 10 ml;
Magne B6 2 tablets twice a day;
No-spa, 1 tablet three times a day;
Partusisten 5 mg four times a day;
Sorbifer or Tardiferon 1 tablet twice a day;
Vitamin E and folic acid 1 tablet three times a day.

A woman will have to take these drugs throughout her pregnancy. If bleeding occurs, it is necessary to call an ambulance or independently get to the maternity hospital and be hospitalized in the department of pathology of pregnant women. In the hospital, No-shpu and Partusisten (or Ginipral) will be injected intravenously in large doses to achieve the effect of strong relaxation of the muscles of the uterus and good stretching of its lower segment. In the future, the woman will again be transferred to tablet forms, which are taken in lower, maintenance dosages.

For the treatment of placental insufficiency and the prevention of fetal hypoxia, the following means are used:

Trental is given intravenously or taken in pill form;
Kurantil take 25 mg 2 - 3 times a day one hour before meals;
Vitamin E take 1 tablet per day;
Vitamin C should be taken at 0.1 - 0.3 g three times a day;
Cocarboxylase is injected intravenously at 0.1 g in glucose solution;
Folic acid is taken orally at 400 mcg per day;
Actovegin take 1 - 2 tablets per day;
Glucose is given intravenously.

Therapy of fetoplacental insufficiency is carried out in courses throughout pregnancy. If the use of these means it is possible to prolong the pregnancy up to 36 weeks, then the woman is hospitalized in the antenatal department and the method of delivery (cesarean section or natural childbirth) is chosen.

If, with placenta previa, severe, persistent bleeding develops, which cannot be stopped within several hours, then an emergency caesarean section is performed, which is necessary to save the woman's life. In such a situation, they do not think about the interests of the fetus, since an attempt to maintain pregnancy against the background of heavy bleeding with placenta previa will lead to the death of both the child and the woman. An emergency caesarean section with placenta previa is performed for the following indications:

Recurrent bleeding, in which the volume of blood lost is more than 200 ml;
Regular meager blood loss against a background of severe anemia and low blood pressure;
One-stage bleeding, in which the volume of lost blood is 250 ml or more;
Bleeding with complete placenta previa.

Childbirth with placenta previa

With placenta previa, childbirth can be carried out both through natural routes and by cesarean section. The choice of delivery method is determined by the condition of the woman and the fetus, the presence of bleeding, and the type of placenta previa.

Caesarean section with placenta previa

Caesarean section with placenta previa is currently performed in 70 - 80% of cases. Indications for cesarean section with placenta previa are the following cases:
1. Complete placenta previa.
2. Incomplete placenta previa, combined with breech presentation or abnormal position of the fetus, a scar on the uterus, multiple pregnancy, polyhydramnios, a narrow pelvis, the age of a primiparous woman over 30 years old and a burdened obstetric history (abortion, curettage, miscarriage, pregnancy loss and uterine surgery );
3. Continuous bleeding with a blood loss of more than 250 ml with any type of placenta previa.

If the listed indications for cesarean section are absent, then with placenta previa, birth can be carried out through natural routes.

Natural birth

Vaginal birth with placenta previa can be performed in the following cases:

The absence of bleeding or its stop after opening the fetal bladder;
Cervix, ready for childbirth;
Regular contractions of sufficient strength;
Head presentation of the fetus.

At the same time, they wait for the independent onset of labor without the use of stimulating drugs. In childbirth, the fetal bladder is opened when the cervix is opened by 1 - 2 cm. If, after opening the fetal bladder, bleeding develops or does not stop, then an emergency caesarean section is performed. If there is no bleeding, then labor continues in a natural way. But with the development of bleeding, an emergency caesarean section is always performed.

Sex and placenta previa

Unfortunately, sex with placenta previa is contraindicated, since frictional movements of the penis can provoke bleeding and placental abruption. However, with placenta previa, not only classic vaginal sex is contraindicated, but also oral and anal sex, and even masturbation, since sexual arousal and orgasm lead to a short-term, but very intense uterine contraction, which can also provoke bleeding, placental abruption or premature birth.

The placenta is the organ of paramount importance in the process of carrying a baby. Therefore, doctors pay special attention to her when examining pregnant women. Normally, this organ is attached closer to the bottom of the uterus and begins to actively grow with the baby. On average, the placenta reaches a mass of 500-600 g and resembles a cake with many blood vessels. But there are many factors that cause abnormal attachment of the placenta in the wrong place and create certain difficulties for the development of the fetus and future childbirth. What is actually marginal placenta previa and how dangerous is such a condition for a pregnant woman?

The physiologically normal placenta attachment site is the bottom of the uterus or areas close to it, mainly on the front and sometimes on the back wall. With various deviations in the health of the mother, the placenta can be located on the opposite side near the pharynx of the uterus. Depending on its location, the following types of placenta previa are diagnosed:

Complete(the placenta completely overlaps the pharynx of the uterus).
Low(the placenta is located close to the pharynx at a distance of no more than 4-5 cm).
Lateral(the pharynx of the uterus is partially covered by the placenta).
Regional(the placenta reaches the pharynx only by the edge).

If the process of implantation of the ovum into the upper segment of the uterus has been disrupted, such a concomitant pathology as the marginal placenta occurs. This means that the "baby seat" is located lower than 2 cm from the birth canal. Sometimes the edge of the placenta reaches the internal os of the uterus. If this situation persists until the 28th week of pregnancy, then we are talking about the marginal attachment of the placenta.

According to statistics, the marginal location of the placenta after 32 weeks of pregnancy remains in only 5% of pregnant women. But they are at risk of pathological childbirth. The perinatal mortality rate increases by 25%.

Pathological placentation: risk factors

Doctors name many reasons for such a common pathology, but no one can give a definitively correct answer. It remains only to take into account all the possible causes of such a pathology.

The marginal location of the placenta is most often localized along the posterior wall of the uterus. This is a threatening pregnancy condition, the appearance of which occurs for several reasons:

Sexually transmitted infections (STIs)... The chronic course of diseases caused by pathogenic coccal flora damages the inner layer of the uterus - the endometrium. At the time of conception, the fertilized egg cannot attach in its proper place and enters the lower part of the uterus, where the endometrium is more functional. In this case, in addition to improper placentation, women often face the threat of termination of pregnancy.
Genetic pathology of the embryo. If the fetus is genetically defective, its trophoblast enzymes are unable to penetrate the endometrial layer to attach there. In most cases, these enzymes are delayed and appear a little later. If this does not happen, then fertilization ends with an arbitrary abortion.
Abnormal uterine structure and traumapostoperative manipulations. Fibroids, polyps or a two-legged structure of the uterus with a depleted endometrium, do not allow the embryo to fully attach in the area of the uterine fundus. It begins to fall and settles in the lower segments of the uterus.
Insufficiency of the endometrium. As a result of scrapings or abortions, a certain layer of the endometrium is removed. If the procedure was carried out by an inexperienced doctor, then women experience insufficient growth of the endometrium and the ovum simply has nowhere to attach.

The main risk factors for marginal placenta previa on the posterior wall:

past delivery by cesarean section;
endometriosis;
drinking and smoking;
over 35 years old;
multiple pregnancy;
adenomyosis;
the presence of a scar on the uterus;
chronic inflammatory processes;
pathologies that interfere with full-fledged implantation.

On a note! We are talking about the consequences of the posterior marginal placenta previa only in the third trimester of pregnancy. Prior to this, the line of the placenta is able to "migrate" along the walls of the uterus and does not pose a particular threat.

Symptoms and diagnosis of marginal placenta previa

The main symptom of the marginal location of the placenta is manifested by spontaneous bleeding of varying intensity. This can be minor bleeding before the 30th week of pregnancy, or severe recurrent bleeding from the slightest contraction of the uterus during childbirth. They can be provoked by both the act of defecation and harmless physical activity.

Bleeding is caused by the fact that the lower sector of the uterus begins to expand during childbirth, involving the part of the uterus in the labor process where the placenta is attached. The uteroplacental cells begin to rupture, which provokes bleeding. This condition threatens the mother with severe blood loss, and the fetus with hypoxia.

Advice! Pregnant women with placenta previa are prohibited from performing ultrasound examination using a vaginal transducer and sexual intercourse.

Diagnostics of the marginal low placenta is carried out using an ultrasound diagnostic apparatus during a routine examination or resorting to the use of MRI in controversial situations. In every third of women with such a pathology, the wrong position of the fetus is determined.

Interesting! Sometimes women, upon examination by a doctor, find out that they have a marginal attachment of the umbilical cord to the placenta. This concept has nothing to do with the marginal presentation of the placenta. It just means that the umbilical cord does not come from the center of the placenta, but from the edge. This is not a deviation from the norm, but a physiological feature.

Possible treatment options

There is no classical drug treatment for this pathology. In 95% of cases, there is a "crawling" of the placenta to its proper place in a natural way. In addition to vitamin complexes and iron preparations (if anemia has arisen from bleeding), the doctor does not prescribe anything. If the woman's condition is unsatisfactory, she is sent to a hospital to preserve her pregnancy.

wearing a special bandage;
exercises in the knee-elbow position so that the fetus takes the correct position;
physiotherapy (according to individual prescription);
sexual rest;
regular bowel movements;
an easy daily routine without physical exertion;
bed rest in the last weeks of pregnancy (in extreme cases);
regular visits to the doctor.

Some statistics! Incorrect placement of the placenta or low placentarity is diagnosed in only one woman in two hundred. The share of marginal placenta previa is 15-20%.

Pregnancy and childbirth management

In case of primary, severe bleeding, a woman is admitted to the hospital and can be there until the 36th week of pregnancy under close supervision. Continuous monitoring of the fetal heart is carried out. When his condition worsens, corticosteroids are prescribed for premature lung maturation. At 34 weeks, an analysis of the amniotic fluid is done to determine the readiness of the fetal lungs to breathe on its own. If the analysis is positive, and the condition of the pregnant woman worsens, then a decision is made about a premature delivery using a cesarean section.

Important! Regional presentation of the placenta is not a contraindication to natural childbirth. Caesarean section is performed only if there are severe complications.

Complications with marginal placenta previa

As already mentioned above, the placenta moves to its proper place in most women closer to the third trimester. Only in 5% of women this does not happen, therefore, such deterioration in the course of pregnancy and childbirth is possible:

The threat of termination of pregnancy or premature labor with subsequent bleeding.
Severe forms of iron deficiency anemia.
Prolonged hypoxia, fetuses and malformations.
Central or marginal placental abruption.
Rupture of the uterus due to fusion of the placenta and uterine wall.
Perinatal death of a child.
Embolism of the mother's blood vessels.
Severe postpartum bleeding.

Summing up

Now that you are aware of what the marginal location of the placenta is and what the consequences are from this, you can responsibly approach the solution of such a problem. Always listen to the advice of your doctor, and if you are in doubt about something, then do not be afraid to seek advice from another specialist. And remember that under the competent supervision of a gynecologist, neither you nor the baby will have any consequences.

The placenta is laid at the very beginning of pregnancy and is fully formed by 16 weeks. It provides nutrition to the fetus, excretion of metabolic products, and also performs the function of the lungs for it, because it is through the placenta that the fetus receives the oxygen necessary for its life. In addition, the placenta is a real "hormonal factory": hormones are formed here that ensure the preservation, normal development of pregnancy, growth and development of the fetus.

The placenta consists of villi-structures, within which the vessels pass. As pregnancy progresses, the number of villi and, accordingly, the number of blood vessels is constantly growing.

Placenta location: norm and pathology

On the side of the uterus, at the placenta attachment site, there is a thickening of the inner membrane. Depressions are formed in it, which form the intervillous space. Some villi of the placenta grow together with the maternal tissues (they are called anchor), while the rest are immersed in the maternal blood, which fills the intervillous space. The anchor villi of the placenta are attached to the partitions of the intervillous spaces; in the thickness of the partitions, there are vessels that carry arterial maternal blood saturated with oxygen and nutrients.

Placental villi secrete special substances - enzymes that “melt” the small arterial vessels that carry maternal blood, as a result of which the blood from them is poured into the intervillous space. It is here that the exchange between the blood of the fetus and the mother takes place: with the help of complex mechanisms, oxygen and nutrients enter the blood of the fetus, and the metabolic products of the fetus into the mother's blood. The connection of the fetus to the placenta is carried out using the umbilical cord. One end of it is attached to the umbilical region of the fetus, the other to the placenta. Two arteries and a vein pass inside the umbilical cord, carrying blood from the fetus to the placenta and back, respectively. Blood rich in oxygen and nutrients flows through the umbilical cord vein to the fetus, and venous blood from the fetus, containing carbon dioxide and metabolic products, flows through the arteries.

Normally, the placenta is located closer to the bottom of the uterus along the front or, less often, the back wall. This is due to the more favorable conditions for the development of the ovum in this area. The mechanism for choosing the place of attachment of the ovum is not completely clear: there is an opinion that the force of gravity plays a role in the choice of the place - for example, if a woman sleeps on the right side, then the egg is attached to the right wall of the uterus. But this is just one of the theories. We can only say unambiguously that the ovum does not attach to places that are unfavorable for this, for example, to the location of myomatous nodes or to places of damage to the inner lining of the uterus as a result of previous scrapings. Therefore, there are other options for the location of the placenta, in which the placenta is formed closer to the lower part of the uterus. Allocate the low location of the placenta and placenta previa.

The low location of the placenta is said when its lower edge is at a distance of no more than 6 cm from the internal os of the cervix. This diagnosis is established, as a rule, during an ultrasound scan. Moreover, in the second trimester of pregnancy, the frequency of this pathology is about 10 times higher than in the third trimester. The explanation is quite simple. Conventionally, this phenomenon is called "migration" of the placenta. In fact, the following happens: the tissues of the lower part of the uterus, which are very elastic, with an increase in gestation, undergo significant stretching and stretch upward. As a result of this, the lower edge of the placenta, as it were, moves upward, and as a result, the location of the placenta becomes normal.

Placenta previa is a more serious diagnosis. In Latin, this condition is called placenta prаevia. "Pre via" literally means before life. In other words, the term "placenta previa" means that the placenta is on the way to the emergence of new life.

Placenta previa is complete or central, when the entire placenta is located in the lower part of the uterus and completely overlaps the internal os of the cervix. In addition, there is a partial placenta previa. It includes marginal and lateral presentation. Lateral placenta previa is said to be when up to 2/3 of the outlet of the uterus is closed by the tissue of the placenta. With a marginal presentation of the placenta, no more than 1/3 of the opening is closed.

Causes of anomalies

The main cause of placental attachment abnormalities is changes in the inner wall of the uterus, as a result of which the process of attachment of a fertilized egg is disrupted.

These changes are most often due to the inflammatory process of the uterus, which occurs against the background of curettage of the uterine cavity, abortion, or associated with sexually transmitted infections. In addition, the deformation of the uterine cavity, caused either by congenital anomalies in the development of this organ, or by acquired causes - uterine myoma (benign tumor of the uterus), predisposes to the development of a similar pathology of the placenta.

Placenta previa can also occur in women suffering from serious diseases of the heart, liver and kidneys, as a result of congestion in the pelvic organs, including the uterus. That is, as a result of these diseases, areas with worse blood supply conditions than other areas appear in the uterine wall.

Placenta previa in multiparous occurs almost three times more often than in women who are carrying their first child. This can be explained by the "baggage of diseases", including gynecological, which a woman acquires by the age of second birth.

It is believed that this pathology of the location of the placenta may be associated with a violation of some functions of the ovum itself, as a result of which it cannot attach in the most favorable area of the uterus for development and begins to develop in its lower segment.

Quite often, placenta previa can be combined with its dense attachment, as a result of which it becomes difficult to separate the placenta independently after childbirth.

It should be noted that the diagnosis of placenta previa, with the exception of its central variant, will be quite correct only closer to childbirth, because the position of the placenta may change. This is all due to the same phenomenon of "migration" of the placenta, due to which, when the lower segment of the uterus is stretched at the end of pregnancy and during labor, the placenta can move away from the area of the internal pharynx and not interfere with normal childbirth.

Caution bleeding!

Bleeding with placenta previa has its own characteristics. It is always external, i.e. blood flows out through the cervical canal, and does not accumulate between the wall of the uterus and the placenta in the form of a hematoma.

Such bleeding always begins suddenly, as a rule, without an apparent external cause, and is not accompanied by any painful sensations. This distinguishes them from bleeding associated with premature termination of pregnancy, when, along with bloody discharge, there are always cramping pains.

Often bleeding begins at rest, at night (woke up "in a pool of blood"). Once it has arisen, bleeding always recurs, with more or less frequency. Moreover, you can never foresee in advance what the next bleeding will be in terms of strength and duration.

After 26-28 weeks of pregnancy, such bleeding can be triggered by physical exertion, intercourse, any increase in intra-abdominal pressure (even coughing, straining, and sometimes by examination by a gynecologist). In this regard, examination on a chair of a woman with placenta previa should be carried out in compliance with all precautions in a hospital setting, where emergency assistance can be provided in case of bleeding. The bleeding itself is life-threatening for mom and baby.

Symptoms and Potential Complications

The main complications and the only manifestations of placenta previa are spotting. Depending on the type of presentation, bleeding may occur for the first time in different periods of pregnancy or childbirth. So, with a central (full) placenta previa, bleeding often begins early - in the second trimester of pregnancy; with lateral and marginal options - in the third trimester or directly in childbirth. The severity of bleeding also depends on the presentation option. With a full presentation, bleeding is usually more profuse than with an incomplete version.

Most often, bleeding occurs at a gestational age of 28-32 weeks, when the preparatory activity of the lower segment of the uterus is most pronounced. But every fifth pregnant woman with a diagnosis of placenta previa notes the appearance of bleeding in the early stages (16-28 weeks of pregnancy).

What is the reason for the appearance of bleeding in placenta previa? During pregnancy, the size of the uterus is constantly increasing. Before pregnancy, they are comparable to the size of a matchbox, and by the end of pregnancy, the weight of the uterus reaches 1000 g, and its size corresponds to the size of the fetus along with the placenta, amniotic fluid and membranes. This increase is achieved mainly due to an increase in the volume of each fiber that forms the wall of the uterus. But the maximum change in size occurs in the lower segment of the uterus, which stretches the more, the closer the term of birth. Therefore, if the placenta is located in this area, then the process of "migration" proceeds very quickly, the low-elastic tissue of the placenta does not have time to adapt to the rapidly changing size of the underlying wall of the uterus, and placental abruption occurs over a greater or lesser extent. At the site of detachment, vascular damage occurs and, accordingly, bleeding.

With placenta previa, the threat of termination of pregnancy is quite often noted: an increased tone of the uterus, pain in the lower abdomen and in the lumbar region. Often, with this arrangement of the placenta, pregnant women suffer from hypotension - a consistently low blood pressure. And a decrease in pressure, in turn, reduces efficiency, causes the appearance of weakness, a feeling of weakness, increases the likelihood of fainting, the appearance of a headache.

In the presence of bleeding, anemia is often detected - a decrease in the level of hemoglobin in the blood. Anemia can worsen symptoms of hypotension, and oxygen deficiency caused by a decrease in hemoglobin levels adversely affects fetal development. There may be growth retardation, fetal growth retardation syndrome (FGRS). In addition, it has been proven that children born to mothers who suffered from anemia during pregnancy always have a reduced hemoglobin level in the first year of life. And this, in turn, reduces the defenses of the baby's body and leads to frequent infectious diseases.

Due to the fact that the placenta is located in the lower segment of the uterus, the fetus often occupies an incorrect position - transverse or oblique. Often there is also a breech presentation of the fetus, when its buttocks or legs are facing the exit from the uterus, and not the head, as usual. All this makes it difficult or even impossible to have a child naturally, without surgery.

Diagnostics

Diagnosis of this pathology is most often not difficult. It is usually established in the second trimester of pregnancy on the basis of complaints of recurrent bleeding without pain.

The doctor on examination or during an ultrasound scan may reveal the incorrect position of the fetus in the uterus. In addition, due to the low location of the placenta, the underlying part of the child cannot descend into the lower part of the uterus, therefore, a characteristic feature is also the high standing of the presenting part of the child above the entrance to the small pelvis. Of course, modern doctors are in a much more advantageous position compared to their colleagues 20-30 years ago. At that time, obstetricians-gynecologists had to navigate only by these signs. After the introduction of ultrasound diagnostics into wide practice, the task has become much simpler. This method is objective and safe; Ultrasound allows you to get an idea of the location and movement of the placenta with a high degree of accuracy. For these purposes, a three-time ultrasound control is advisable at 16, 24-26 and 34-36 weeks. If, according to the ultrasound examination, the pathology of the location of the placenta is not detected, the doctor during the examination may reveal other causes of bleeding. They can be various pathological processes in the vagina and cervix.

Observation and treatment

An expectant mother diagnosed with placenta previa needs careful medical supervision. Timely clinical trials are of particular importance. When detecting even a slightly reduced hemoglobin level or disorders in the blood coagulation system, a woman is prescribed iron preparations, because in this case, there is always a risk of rapid development of anemia and bleeding. If any, even minor, deviations in the state of health are identified, consultations of the appropriate specialists are required.

Placenta previa is a formidable pathology, one of the main causes of serious obstetric bleeding. Therefore, if bleeding develops, all the health problems a woman has, even small ones, can aggravate her condition and lead to adverse consequences.

In the presence of bloody discharge, the observation and treatment of pregnant women with placenta previa during pregnancy over 24 weeks is carried out only in obstetric hospitals that have conditions for the provision of emergency care in an intensive care unit. Even if the bleeding has stopped, the pregnant woman remains under the supervision of the hospital doctors until the due date.

In this case, treatment is carried out depending on the strength and duration of bleeding, gestational age, general condition of the woman and the fetus. If the bleeding is insignificant, the pregnancy is premature and the woman is feeling well, conservative treatment is carried out. Strict bed rest is prescribed, drugs to reduce the tone of the uterus, improve blood circulation. In the presence of anemia, a woman takes drugs that increase the level of hemoglobin, restorative drugs. To reduce emotional stress, sedatives are used.

Plus diet regimen

If there is no bleeding, especially with a partial variant of placenta previa, a woman can be observed on an outpatient basis.

The diet must necessarily contain foods rich in iron: buckwheat, beef, apples, etc. Adequate protein content is essential. without it, even with a large intake of iron in the body, hemoglobin will remain low: in the absence of protein, iron is poorly absorbed. Eating fiber-rich fruits and vegetables on a regular basis is beneficial. stool retention can provoke the appearance of spotting. Laxatives are contraindicated in placenta previa. As with all pregnant women, patients with placenta previa are prescribed special multivitamin preparations. If all these conditions are met, the manifestations of all the symptoms described above, accompanying in most cases placenta previa, are reduced, which means that conditions are provided for the normal growth and development of the child. In addition, in the event of bleeding, the adaptive capabilities of the woman's body increase, and blood loss is more easily tolerated.

Childbirth

With full placenta previa, even in the absence of bleeding, a caesarean section is performed at 38 weeks of gestation. spontaneous childbirth in this case is impossible. The placenta is located on the way of the baby's exit from the uterus, and when trying to give birth independently, its complete detachment will occur with the development of very severe bleeding, which threatens the death of both the fetus and the mother.

The operation is also resorted to at any stage of pregnancy in the presence of the following conditions:

Placenta previa, accompanied by significant bleeding, life-threatening;

Recurrent bleeding with anemia and severe hypotension, which are not eliminated by the appointment of special drugs and are combined with a violation of the fetus.

In a planned manner, a caesarean section is performed for a period of 38 weeks with a combination of partial placenta previa with another pathology, even in the absence of bleeding.

If a pregnant woman with partial placenta previa brought the pregnancy before the due date, in the absence of significant bleeding, it is possible that the birth will occur naturally. When the cervix is dilated by 5-6 cm, the doctor will finally determine the option for placenta previa. With a small partial presentation and minor bloody discharge, the fetal bladder is opened. After this manipulation, the fetal head descends and squeezes the bleeding vessels. The bleeding stops. In this case, it is possible to complete the labor in a natural way. If the measures taken are ineffective, childbirth ends quickly.

Unfortunately, after the baby is born, there is a risk of bleeding. This is due to a decrease in the contractility of the tissues of the lower segment of the uterus, where the placenta was located, as well as to the presence of hypotension and anemia, which have already been mentioned above. In addition, it has already been mentioned about the frequent combination of presentation and dense attachment of the placenta. In this case, the placenta after childbirth cannot completely separate itself from the walls of the uterus and it is necessary to carry out a manual examination of the uterus and the separation of the placenta (the manipulation is carried out under general anesthesia). Therefore, after childbirth, women who had placenta previa remain under the close supervision of hospital doctors and must carefully follow all their recommendations.

Rarely, but still there are cases when, despite all the efforts of doctors and the performed caesarean section, the bleeding does not stop. In this case, you have to resort to removing the uterus. Sometimes this is the only way to keep a woman alive.

Precautionary measures

It should also be noted that when placenta previa, one should always keep in mind the possibility of severe bleeding. Therefore, it is necessary to discuss with the doctor in advance what to do in this case, to which hospital to go. Staying at home, even if the bleeding is not profuse, is dangerous. If there is no preliminary agreement, you need to go to the nearest maternity hospital. In addition, with placenta previa, it is often necessary to resort to blood transfusion, therefore, if you have been diagnosed with such a diagnosis, find out in advance which of the relatives has the same blood group as you, and obtain his consent, if necessary, to donate blood for you (the relative must get tested in advance for HIV, syphilis, hepatitis).

You can arrange in the hospital where you will be monitored so that your relatives donate blood for you in advance. At the same time, it is necessary to secure a guarantee that the blood will be used just for you - and only if you do not need it, it will be transferred to the general blood bank. It would be ideal for you to donate blood for yourself, but this is possible only if your condition does not cause concern, all indicators are normal and there is no bloody discharge. Storage blood can be donated several times during pregnancy, but it also needs to be assured that your blood will not be used without your knowledge.

Although placenta previa is a serious diagnosis, modern medicine allows you to bear and give birth to a healthy child, but only if this complication is diagnosed in a timely manner and with strict adherence to all doctor's prescriptions.

When everything is over and you and your baby are at home, try to organize your life correctly. Try to get more rest, eat right, be sure to walk with your baby. Don't forget about multivitamins and medications to treat anemia. If possible, do not give up breastfeeding. This will not only lay the foundation for the baby's health, but also accelerate the recovery of your body, because Stimulating the nipple while sucking causes the uterus to contract, reducing the risk of PPH and uterine inflammation. It is advisable that at first someone help you in caring for your child and household chores, because your body has gone through a difficult pregnancy, and it needs to recover.