Placenta previa is currently considered a pathology of pregnancy, and at 37–40 weeks of gestation it occurs in 0.2–3.0% of cases. For more early stages During pregnancy, placenta previa is observed more often (up to 5–10% of cases), however, as the fetus grows and develops, the uterus stretches, and it children's place moves further from the cervical region. Obstetricians call this process “placenta migration.”
To understand the essence of the pathological location of the placenta, called previa, it is necessary to imagine the structure of the uterus, which is conventionally divided 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 upper part of the uterus, which is the horizontal area directly opposite the cervix, is called the fundus. And the side walls located between the fundus and the cervix are called the body of the uterus.
The cervix is a kind of tightly compressed cylinder of muscle tissue with an opening inside called the cervical canal. If this cylinder is stretched in width, 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 labor, the cervix is tightly collapsed and the opening 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 rope that is the tightly compressed cervix that keeps the contents of the sac from falling out. Now turn this bag over with the opening facing down so that the part tied with 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 fundus is at the top, and the cervix is at the bottom.
During childbirth, the cervix opens (pops) under the influence of contractions, resulting in a hole through which the baby can pass. In relation to the image of a bag, the process of opening the cervix is equivalent to simply untying the string that tightens its opening. As a result of this “opening” of the bag, everything in it will fall out. But if you untie the opening of the bag and at the same time place some kind of obstacle in front of it, the contents will remain inside, since they simply cannot fall out. Likewise, a child will not be able to be born if there is any obstacle on its way, at the site of the opening of the cervix. The placenta, located in the cervical area, is precisely such an obstacle. And its location, which interferes with the normal course of the birth 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 with placenta previa is due to the relatively high incidence of premature birth, placental insufficiency and abnormal position of the fetus in the uterus. In addition to high infant mortality, placenta previa can cause a serious complication - bleeding in a woman, which kills about 3% of pregnant women. It is precisely because of the danger of children and maternal mortality Placenta previa is considered a pregnancy pathology.
Types of placenta previa and their characteristics
Depending on the specific features of the location of the placenta in the cervix, 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 labor when the cervix is dilated by 4 cm or more. It should be remembered that the degree and type of presentation may change as the uterus grows or as the cervix increases in dilation.Based on transvaginal ultrasound data performed during pregnancy, the following types of placenta adherence are distinguished:
1.
Full presentation;
2.
Not full presentation;
3.
Low presentation (low position).
Complete placenta previa
Complete placenta previa (placenta praevia totalis - lat.). IN in this case The placenta completely covers the internal opening of the cervix (internal os). This means that even if the cervix is fully dilated, the baby will not be able to enter the birth canal, since his path will be blocked by the placenta, which completely blocks the exit from the uterus. Strictly speaking, natural birth with complete placenta previa is impossible. The only option for delivery in such a situation is C-section. This location of the placenta is observed 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, infant and maternal mortality. Incomplete (partial) placenta previa
In case of incomplete (partial) presentation (placenta praevia partialis), the placenta covers the internal opening of the cervix only partially, leaving a small area of its total diameter free. Partial placenta previa can be compared to a plug that closes part of the diameter of the pipe, preventing water from moving at the maximum possible speed. Also referred to as incomplete presentation is 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 internal opening of the cervix are at the same level. With incomplete placenta previa, the baby's head, as a rule, cannot pass into the narrow part of the lumen of the cervix, so childbirth in a natural way is impossible in the vast majority of cases. The frequency of occurrence of this type of presentation ranges from 35 to 55% of cases.
Low (lower) 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 (entrance to the cervical canal) with low presentation is not captured and not covered by part of the placenta. Against the background of low placenta previa, natural childbirth is possible. This pathology option is the most favorable from the point of view of the risk of complications and pregnancy. According to the results of ultrasound, more and more often in last years For clinical practice, obstetricians resort to determining not the type, but the degree of placenta previa during pregnancy, which is 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 opening of the cervix, but its edge is at least 3 cm away from the pharynx (conditionally corresponds to 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 block it (conditionally corresponds to incomplete placenta previa);
- III degree– the lower part of the placenta completely blocks the entrance to the cervical canal. In this case, most of the placenta is located on any one wall (anterior or posterior) of the uterus, and only a small area closes the entrance to the cervical canal (conditionally corresponds to complete placenta previa);
- 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. In this case, identical parts of the placenta are located on the anterior and posterior walls of the uterus (conditionally corresponding to complete placenta previa).
Besides, long time the so-called clinical classification of placenta previa was used, based on determining its location during labor when the cervix is dilated by 4 cm or more. Based on vaginal examination during childbirth, the following types of placenta previa are distinguished:
- Central placenta previa (placenta praevia centralis);
- Lateral placenta previa (placenta praevia lateralis);
- Regional placenta previa (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 membranes. Natural birth with central placenta previa is impossible, and the only way for a child to be born in such a situation is a caesarean section. Relatively speaking, central placenta previa, determined during a vaginal examination during childbirth, corresponds to complete, as well as grade III or IV according to ultrasound results.Lateral placenta previa
In this case, during a vaginal examination, the doctor determines the part of the placenta that covers the entrance to the cervical canal and the rough membranes located next to it. Lateral placenta previa, determined by vaginal examination, corresponds to incomplete (partial) or II-III degree according to ultrasound results.Regional placenta previa
During a vaginal examination, the doctor determines only the rough membranes of the fetus protruding into the lumen cervical canal, and the placenta is located at the very edge of the internal os. Regional placenta previa, determined by vaginal examination, corresponds to incomplete (partial) or grades I-II according to ultrasound results. Posterior placenta previa (placenta previa along the posterior wall)
This condition is a special case of incomplete or low presentation, in which the main part of the placenta is attached to back wall 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. 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 The placenta is determined by ultrasound results up to 26–27 weeks of pregnancy, which can migrate within 6–10 weeks and return to its normal position by the time of birth.
Placenta previa - causes
The placenta is formed in the area of the uterus where the fertilized egg 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 fertilized egg, and it searches for such a part of the uterus that has the most favorable conditions for its survival (good thick endometrium, absence of neoplasms and scars, etc.). If for some reason the best endometrium ends up in the lower segment of the uterus, then the fertilized egg will attach there, and subsequently this will lead to placenta previa.The reasons for the attachment of the fertilized egg 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 fetal egg).
Uterine factors- these are different pathological changes 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 fertilized egg, which allow it to implant into the uterine mucosa. Due to a lack of enzyme activity, the fertilized egg “slips” past the bottom and walls of the uterus and implants only in its lower part.
Currently, the following conditions are classified as uterine causes of placenta previa:
- Any surgical interventions on the uterus in the past (abortion, cesarean section, removal of fibroids, etc.);
- Childbirth that occurred with complications;
- Anomalies in the structure of the uterus;
- Underdevelopment of the uterus;
- Isthmic-cervical insufficiency;
- Multiple pregnancy (twins, triplets, etc.);
- Endocervicitis.
TO fetal reasons The following factors include placenta previa:
- Inflammatory diseases of the genital organs (adnexitis, salpingitis, hydrosalpinx, etc.);
- Complicated obstetric history (abortion, diagnostic curettage, difficult childbirth in the past);
- Any previous surgical interventions on the uterus;
- Neuro-endocrine dysregulation of menstrual function;
- Underdevelopment of the genital organs;
- Inflammatory diseases of the genital organs;
- Uterine fibroids;
- 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 the following:- Bloody discharge from the genital tract is bright scarlet in color with a completely painless and relaxed uterus;
- High position of the fundus of the uterus (the indicator is greater than that which is typical for a given stage of pregnancy);
- Incorrect 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 an ultrasound cannot be done, then to confirm the diagnosis of placenta previa, the doctor performs a very careful, careful and careful vaginal examination. With placenta previa, the gynecologist feels the spongy tissue of the placenta and rough membranes with his fingertips.
If a woman does not have any clinical manifestations If placenta previa occurs, that is, the pathology is asymptomatic, it is detected during screening ultrasound examinations, which are mandatory at 12, 20 and 30 weeks of pregnancy.
Based on the ultrasound data, the doctor decides whether a vaginal examination can be performed on 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 diagnosis of placenta previa is currently the most informative and safe method identifying this pathology. Ultrasound also allows you to clarify the type of presentation (complete or partial), measure the area and thickness of the placenta, determine its structure and identify areas of abruption, if any. To determine various characteristics of the placenta, including presentation, ultrasound must be performed with moderate filling of the bladder. If placenta previa is detected, then periodically, at intervals of 1–3 weeks, an ultrasound scan is performed to determine the speed of its migration (movement along the walls of the uterus higher). To determine the position of the placenta and assess the possibility of a natural birth, 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 ultrasound 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 in different terms gestation - starting from 12 weeks until birth, however, most often they are observed in the second half of pregnancy due to severe stretching of the walls of the uterus. With placenta previa, bleeding occurs before 30 weeks 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 labor activity. In general, with placenta previa, bleeding is observed in 34% of women during pregnancy, and in 66% during childbirth. During the last 3 to 4 weeks of pregnancy, when the uterus contracts especially strongly, bleeding may increase.Bleeding during placenta previa is caused by its partial detachment, which occurs as the uterine wall 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 activity, severe coughing, vaginal examination, visiting a sauna, sexual intercourse, defecation with strong straining, etc.
Depending on the type of placenta previa, the following types of bleeding are distinguished:
- Sudden, heavy 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 scanty discharge.
- Start of bleeding last days pregnancy or childbirth is typical for incomplete placenta previa.
Given the repeated episodes of bleeding during placenta previa, pregnant women with this pathology almost always experience severe anemia, a lack of circulating blood volume (BCV) and low blood pressure (hypotension). These nonspecific signs can also be considered symptoms of placenta previa.
The following signs are also considered indirect symptoms of placenta previa:
- Incorrect presentation of the fetus (oblique, transverse, breech);
- High position of the fundus of the uterus;
- Listen to the sound of blood in the vessels at the level of the lower segment of the uterus.
What threatens placenta previa - possible complications
Placenta previa can lead to the development of the following complications: - Threat of miscarriage;
- Iron-deficiency anemia;
- Incorrect position of the fetus in the uterus (oblique or transverse);
- Breech or leg presentation of the fetus;
- Chronic fetal hypoxia;
- Fetal growth retardation;
- Fetoplacental insufficiency.
Preeclampsia with placenta previa is caused by the impossibility of a full second trophoblast invasion into the endometrium, since in the lower segment of the uterus the mucous membrane is not dense and thick enough for additional villi to penetrate into it. That is, disruption of the normal growth of the placenta during its presentation provokes gestosis, which, in turn, increases the severity and 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 fundus or body, as a result of which an insufficient amount of blood reaches the placenta. Poor blood flow causes insufficient oxygen and nutrients to reach the fetus and therefore not meet its needs. Against the background of such a chronic deficiency of oxygen and nutrients, hypoxia and delayed fetal development are formed.
Iron deficiency anemia is caused by constantly recurring periodic bleeding. Against the background of chronic blood loss, in addition to anemia, a woman develops a deficiency in circulating blood volume (CBV) and coagulation factors, which can lead to the development of disseminated intravascular coagulation syndrome and hypovolemic shock during childbirth.
Incorrect positioning of the baby or its 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 is occupied by the placenta.
Placenta previa - principles of treatment
Unfortunately, there is currently no specific treatment that can change the attachment site and location of the placenta in the uterus. Therefore, therapy for placenta previa is aimed at stopping bleeding and maintaining pregnancy as long as possible - ideally until the due date. If placenta previa occurs throughout pregnancy, the woman must observe a protective regime aimed at excluding various factors that can cause bleeding. This means that a woman needs to limit physical activity, do not jump or drive on bumpy roads, do not fly on an airplane, do not have sex, avoid stress, do not lift heavy objects, etc. IN free time You should lie on your back with your legs thrown up, for example, on a wall, on a table, on the back of a sofa, etc. The “lying on your back with your legs raised” position should be taken whenever possible, preferring it to simply sitting on a chair, in an armchair, etc.
After 24 weeks, if the bleeding is light and stops on its own, the woman should receive conservative treatment aimed at maintaining pregnancy until 37 - 38 weeks. Therapy for placenta previa involves the use of the following drugs:
- Tocolytic and antispasmodic drugs that improve 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.);
- Drugs to improve blood supply to the fetus (Ascorutin, Curantil, Vitamin E, folic acid, Trental, etc.).
- Intramuscular injection of 20 - 25% magnesia, 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.
For the treatment of feto placental insufficiency and the prevention of fetal hypoxia, the following means are used:
- Trental is administered intravenously or taken in tablet form;
- Curantil take 25 mg 2 – 3 times a day an hour before meals;
- Vitamin E take 1 tablet per day;
- Vitamin C take 0.1 - 0.3 g three times a day;
- Cocarboxylase is administered intravenously at 0.1 g in a glucose solution;
- Folic acid taken orally 400 mcg per day;
- Actovegin take 1 – 2 tablets per day;
- Glucose is administered intravenously.
If, during 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 severe bleeding with placenta previa will lead to the death of both the child and the woman. Emergency caesarean section for placenta previa is performed for the following indications:
- Recurrent bleeding, in which the volume of blood lost is more than 200 ml;
- Regular scanty blood loss against the background of severe anemia and low blood pressure;
- Simultaneous bleeding, in which the volume of lost blood is 250 ml or more;
- Bleeding with complete placenta previa.
Childbirth with placenta previa
In case of placenta previa, childbirth can be carried out either through natural means or by cesarean section. The choice of delivery method is determined by the condition of the woman and fetus, the presence of bleeding, as well as the type of placenta previa.Caesarean section for placenta previa
Caesarean section for placenta previa is currently performed in 70–80% of cases. Indications for caesarean section for placenta previa are the following cases: 1. Complete placenta previa.
2. Incomplete placenta previa, combined with breech or abnormal location of the fetus, a scar on the uterus, multiple pregnancies, polyhydramnios, a narrow pelvis, the age of the primiparous woman over 30 years old and a burdened obstetric history (abortions, curettage, miscarriages, pregnancy losses and uterine surgeries in the past);
3. Continuous bleeding with a blood loss volume of more than 250 ml with any type of placenta previa.
If the listed indications for cesarean section are absent, then with placenta previa, childbirth can be carried out through natural means.
Natural birth
Vaginal delivery with placenta previa can be carried out in the following cases:- Absence of bleeding or its stopping after opening of the amniotic sac;
- The cervix is ready for childbirth;
- Regular contractions of sufficient strength;
- Head presentation of the fetus.
Sex and placenta previa
Unfortunately, sex during placenta previa is contraindicated, since frictional movements of the penis can cause bleeding and placental abruption. However, with placenta previa, not only classic vaginal sex is contraindicated, but also oral, anal, and even masturbation, since sexual arousal and orgasm lead to short-term but very intense contractions of the uterus, which can also provoke bleeding, placental abruption or premature birth.Normally, the placenta is attached to the upper part of the uterus and, when the baby is born, remains inside for some time, supplying the baby with oxygen and allowing him to calmly take his first breath. However, sometimes the placenta is not in place - it partially or completely blocks the “exit” from the uterus and, accordingly, the child cannot leave “his home” first. The complication is rare, but, alas, not exotic.
How do pregnancy and childbirth proceed with placenta previa?
The placenta is a new organ of a pregnant woman
Many expectant mothers anxiously await the birth of their baby, tracking his growth week by week and even by day. But few people think that along with the baby, a unique new organ appears and develops inside a woman - . And the organ, by the way, is quite large - it weighs as much as half a kilo! If we talk about its functions, then it becomes clear that it’s not “whole”, but “only” half a kilo.
Firstly, it allows you to take water, electrolytes, nutrients and minerals, vitamins, and most importantly, oxygen from the mother’s blood. But at the same time, the blood of mother and baby does not mix - isn’t it a miracle?
Secondly, remove everything unnecessary from the baby’s body, first of all, carbon dioxide, because the baby breathes, although he does not inhale and exhale.
Thirdly, the placenta produces (or promotes the production) of various hormones: including human chorionic gonadotropin, progesterone, prolactin, and estrogens, and this is not a complete list.
Finally, the placenta is a kind of “guardian” that takes from the mother’s blood useful material(for example, some antibodies that provide the child with immune protection from birth) and does not allow harmful ones to pass through.
” A healthy placenta, which grows and develops with the baby, is the key to his health and well-being. But she may suffer if she finds herself “in the wrong place at the wrong time.”
Placenta location: above, side, below
The best location for the placenta is at the top (where the fundus of the uterus is located) on the back wall (the side of the uterus “facing” the spine). Why?
During growth, the uterus stretches in front and downwards - there its wall becomes thinner, and the blood supply, accordingly, worsens. The anterior wall of the uterus is more vulnerable - an accidental fall or blow can hit the placenta, while at the back it is reliably protected by the body of the uterus and amniotic fluid. But most importantly, the wall of the uterus stretches, but the placenta is not so elastic. If it is located in front and below, then the placenta simply “does not keep up” with the wall of the uterus and is constantly “detached”.
The lower the placenta is located (especially if we are talking about the anterior wall), the more vulnerable it is. If 5-6 centimeters remain from its edge to the cervix, then they speak of - a condition requiring special attention doctors and the pregnant woman herself.
” However, it happens that the placenta is located so low that it partially or completely closes the cervical canal - the “passage” in the cervix that should open slightly during childbirth.
If childbirth takes place naturally, the placenta will be “born” first. At this moment, the blood supply to the child will stop; the unborn baby will literally be “cut off oxygen.” The chances of survival during natural childbirth are minimal.
” Fortunately, this is a fairly rare complication - it occurs no more than 1% of the total number of births. And only in 20 cases of all presentations is complete presentation observed, when the placenta completely covers the area of the internal os.
Why does placenta previa occur?
When a fertilized egg comes from fallopian tube into the body of the uterus, it naturally ends up at the very top, where the exits from the tubes are located. Usually, attachment of the fertilized egg to the wall of the uterus occurs immediately, which is why the placenta in most cases is attached from above, at the bottom of the uterus.
” If attachment does not occur for some reason, the fertilized egg, under the influence of gravity, sinks lower and lower until it finally “finds” a place where it can attach. Sometimes a favorable area is found only at the internal os of the uterus - it is there that the placenta begins to grow.
But why does attachment not occur where nature intended? The reason is damage to the inner layer of the endometrium. This may be a consequence:
inflammation;
surgery (abortion, cesarean section, removal of tumors or placenta accreta during a previous birth);
neoplasms (for example, uterine fibroids)
endometriosis;
malformations of the uterus;
” Placenta previa is rare in first pregnancies, but the more pregnancies a woman has, the higher the likelihood of complications.
How does placenta previa manifest?
Positioned in such an unfortunate manner, the placenta is constantly “torn off” from the stretching walls of the uterus. Therefore, such pregnant women have frequent uterine bleeding. Sometimes they begin already in the first trimester, and almost always in the second half of the term. Any contractions of the uterus (including training contractions) provoke their intensification.
” After partial placental abruption, the uterine wall, saturated with blood vessels, bleeds. The embryo, as we have already mentioned, has an independent circulatory system and does not lose blood. However, its development suffers due to deterioration in the supply of oxygen and nutrients.
Also, factors that provoke bleeding can be:
coughing or sneezing that causes tension in the abdominal wall;
straining during bowel movements, especially with constipation;
bath, sauna and hot tub.
Painful sensations usually do not occur; bleeding often begins and ends suddenly for the pregnant woman herself. It can be scanty (spotting bloody issues), and frighteningly abundant.
Development of pregnancy with placenta previa
The position of the placenta may change during pregnancy. After all, this is a living, functioning organ, in which some areas can die off, while others, on the contrary, can grow. In addition, the wall of the uterus can stretch below the placenta, and thus it will rise. It is important that the doctor monitors its position - this is usually done using an ultrasound at the 12-16th, 20-22nd and 36th weeks of pregnancy, but if necessary, the doctor can conduct the study more often.
” From the point of view of placenta migration, its location on the anterior wall of the uterus is favorable: it stretches more and, accordingly, more likely that the placenta will rise.
If placenta previa persists, then the expectant mother is at risk of anemia - the body during pregnancy already has to increase the volume of circulating blood (by about a liter), and if it is also necessary to compensate for regular blood loss, then the hemoglobin level may drop to critical. The baby, accordingly, experiences hypoxia, which slows down its development and negatively affects the development of the baby’s brain.
But the most dangerous thing is, of course, placental abruption. The larger the area separated from the wall of the uterus, the worse the supply of oxygen and nutrients to the baby. In extreme cases, this can lead to intrauterine death fetus
” If no more than a quarter of the area of the placenta has detached, then the prognosis for the child is relatively favorable. Detachment of more than 1/3 of the placenta most often leads to fetal death.
Approximately one in three pregnancies with placenta previa experience low blood pressure.
Placenta previa. What to do?
Lie! This, of course, is some exaggeration, but still the main rule for a pregnant woman with placenta previa is maximum rest. No physical or emotional stress (stress can also cause uterine spasms) and no intimate life. However, if there is no regular heavy bleeding, in the first half of pregnancy a woman can stay at home and do simple household things.
Starting from the 24th week, pregnant women with placenta previa, especially complete, are hospitalized. What awaits a pregnant woman in the hospital?
Bed rest. Even in the absence of bleeding, compliance with it is vital for the baby's health.
Treatment aimed at preventing any contractions of the uterus. Periodic spasms are completely normal phenomenon, and at the end of pregnancy they are completely necessary: this is how the body prepares for childbirth. However, they are detrimental to the placenta previa.
Treatment of anemia and symptoms . It is necessary to compensate mother and child for the lack of oxygen and nutrients arising from constant placental abruptions.
” In the hospital, they try to extend pregnancy, if possible, to 37-38 weeks.
How to give birth with placenta previa
Alas, with complete placenta previa, the possibility of natural childbirth is completely excluded. After all, in order to clear the way for the baby, the placenta must completely separate and exit the uterus. And as soon as it separates, the child will be deprived of oxygen and will reflexively try to breathe - he will simply drown in the intrauterine fluid. This is why pregnant women are not discharged from the hospital, even if they are not bleeding. Sudden bleeding, a drop in blood pressure, critical hemoglobin levels - all these are direct indications for an emergency cesarean section.
Cesarean section is also performed in the presence of scars on the uterus, multiple pregnancies and incorrect position fetus, which is especially common with placenta previa.
” In case of incomplete (marginal) placenta previa, the obstetrician-gynecologist acts “according to the situation.” The main guideline is the presence of bleeding.
If the baby is positioned correctly, there is no or little bleeding, and the cervix is ready to dilate, then the amniotic sac is opened. The baby lowers himself and presses the placenta against the wall of the uterus with his head, preventing it from detaching. At the same time, the baby puts pressure on the cervix, causing it to open faster. If the bleeding not only does not stop, but even intensifies, emergency surgery is performed.
” Natural birth with incomplete placenta previa is possible, but in reality it occurs in no more than 25-20% of cases. Too many favorable circumstances must come together: the correct positioning of the child, and the cessation of bleeding under fetal pressure, and high degree cervical maturity, and active labor.
Another problem of childbirth with placenta previa is... separation of the placenta after the birth of the baby! It would seem that what the problem is - the placenta was already trying to detach for 9 months. However, the uterus contracts unevenly after childbirth. The strongest is the upper section, where the fundus of the uterus is located. And the stretched lower one contracts much longer and weaker. Therefore, firstly, areas of the placenta that were not separated during pushing are then separated with great difficulty. And secondly, after its separation, heavy uterine bleeding occurs, since weak spasms do not “pinch” small blood vessels.
How to avoid placenta previa
Probably, if you are just thinking about your upcoming pregnancy, you want to avoid such an unpleasant complication as placenta previa. To do this you need:
avoid termination of pregnancy, especially medical abortion (up to 12 weeks), preferring another method of contraception;
treat any problems promptly and completely inflammatory diseases reproductive organs;
in the presence of hormonal disorders follow all recommendations of the gynecologist-endocrinologist.
Fortunately, even complete placenta previa is not a death sentence. Obstetricians will help you carry and give birth healthy child, the main thing is calm and strict adherence to all medical recommendations!
Prepared by Anna Pervushina
Successful pregnancy depends on many factors. One of them is the place of attachment of the amniotic sac. In case of deviations, placenta previa occurs during pregnancy. To prevent complications, it is necessary to identify pathology and determine the causes of its occurrence.
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What is placenta previa
Often, when examining a pregnant woman’s condition, placenta previa is diagnosed. There is a need to study what it is and how it manifests itself.
Note! The amniotic sac plays an important role in the life support of the gestating fetus.
The bladder ensures interaction between the body of mother and child. This body performs the following functions:
- gas exchange;
- nutritious;
- immunoprotective;
- hormonal.
The physiological location of the fertilized egg suggests its location on:
- fundus of the uterus;
- posterior and lateral walls of the uterine body.
This area is least subject to change. It is also the area of best vascularization.
Attachment to the posterior wall ensures that the embryo is protected from unexpected damage. When the bubble is attached from the pharynx, then a violation occurs.
Placenta previa is pathological location amniotic sac.
As a result, the embryo develops in the wrong place. It should be borne in mind that this condition directly affects the outcome of labor.
The danger of pathology lies in limiting delivery. Since the organ is located in the lower part of the uterus, the birth canal is blocked.
This condition poses a threat to fetal development. Subject to detection of pathology the likelihood increases:
- prematurity of the child;
- fetoplacental insufficiency;
- premature birth;
- perinatal death;
- maternal death (due to blood loss and hemorrhagic shock).
This disorder is more often diagnosed in the early stages pregnancy. Closer to 40 weeks, the number of pathological cases decreases. This is due to "bubble migration". As the fetus develops, the uterus stretches, causing the embryo to move away from the cervix.
Causes of placenta previa
There is still no consensus on what influences the appearance of pathology. There is also no way to influence placental formation. Generally reasons for presentation Placentas can be divided into the following categories:
- Aspects of embryonic development.
- Aspects that determine the health of a pregnant woman.
To the features embryonic structure it is customary to refer to:
- trophoblast implantation failure;
- weak enzymatic action;
- delay in the development of the fertilized egg.
The presence of these factors makes it impossible for the fetus to implant in the upper section.
The condition of the maternal body is determined by the following phenomena:
- inflammation in the endometrial area (frequent);
- processes of endometrial atrophy;
- diseases of infectious nature;
- stagnant processes in the reproductive organs (are a consequence of chronic pathologies of the cardiovascular and endocrine system, as well as slow blood supply);
- surgical intervention in the uterine area;
- cases of gestation period;
- complications after previous labor;
- anomalous structure uterus;
- detection of endometriosis and uterine fibroids;
- underdevelopment of the uterus;
- the presence of isthmic-cervical insufficiency;
- presence of endocervicitis;
- pathological processes in the cervical area;
- neuro-endocrine disorders;
- previously diagnosed facts of pathological location;
- exposure to addictions (systematic use of nicotine, alcohol-containing liquids and narcotic substances);
- multiple births;
- hormonal imbalance.
These causes of placenta previa affect the formation of the mucous membrane in the uterine area. If it is underdeveloped, the lower part of the cavity is an acceptable place.
Placenta previa: types
In medical practice it is customary to distinguish different kinds violations . Their classification is based on the following factors:
- determining the location of the ovum using transvaginal ultrasound;
- identification of the location of the ovum during labor (the condition for fulfillment is the presence of a 4-centimeter cervical dilatation or more).
The results of transvaginal examination allow us to divide pathology into the following types:
- full;
- incomplete;
- low.
Data obtained during delivery determine the existence of the following types of disorders:
- central;
- lateral;
- regional
Complete placenta previa
Complete presentation is presented in the form of a thorough overlap of the uterine pharynx with placental tissue.
This position of the amniotic sac creates restrictions for natural delivery. Even with the cervix fully dilated, the fetus won't be able to continue movement along the birth canal.
Full presentation is also known as centric position.
Its peculiarity is the need to carry out . Other types of pathology do not exclude the possibility that the amniotic sac will move. In the case of the central type, such an outcome of events does not exist.
Central placenta previa dangerous with the following consequences:
- complete placental abruption long before labor;
- the occurrence of embryonic hypoxia;
- slow development of the child;
- ovum accretion;
- early rupture of membranes.
This attachment provides for complete exclusion of intimacy and minimizing physical stress.
Incomplete placenta previa
Incomplete placenta previa is partial overlap internal opening of the cervix. With this arrangement, a small area remains free.
Incomplete placenta previa is also known as partial placenta previa. A subtype of this pathology is the marginal and lateral location.
The marginal location determines the presence of the lower part of the fertilized egg near the edge of the internal opening of the cervix. In this case, it can be either along the front wall or along the rear arch. A single level is noted for the cervix and placental edge. When positioned sideways, there is partial overlap.
This violation determines the impossibility of passing the child's head into the neck. This feature makes it possible to carry out caesarean section.
Regional placenta previa can be diagnosed by the anterior wall.
Anterior placement of the placenta is an option gynecological norm. Such a case is not usually classified as a pathological attachment.
This is due to the likelihood of stretching the uterus under the weight of the fetus and its further movement along the anterior wall.
Marginal presentation of the placenta along the posterior wall is usually classified as low or incomplete attachment of the membranes. It manifests itself as being on the posterior fornix.
This option is less dangerous than placing it on the front wall. This is explained by the difference in the load on the uterine area. However, they can bleeding occurs.
Low placenta previa
What is low presentation placenta during pregnancy, what threatens the condition of the expectant mother and child - aspects of interest for study.
The low position suggests that the amniotic sac is at the level less than 7 cm from the beginning of the cervical canal. There is no overlap of the placenta with the internal cervical os.
This situation not considered a contraindication to natural delivery. Among existing pathologies, it is considered the most favorable for the period of gestation and childbirth.
There is the following classification of low location:
- 1st degree (distance to the cervical canal – 3 cm);
- 2nd degree (there is fixation of the fertilized egg near the beginning of the cervical canal without blocking the entrance);
- 3rd degree (partial or complete overlap is noted, as well as placental displacement along the vault);
- 4th degree (pronounced complete blocking).
With the first two degrees, natural delivery is possible. The latter degrees presuppose surgical intervention.
The danger of low presentation
Experts often diagnose low placenta previa during pregnancy. What threatens this condition is the main question for pregnant women.
Among the complications that arise against the background of this arrangement, it is customary to highlight:
- Risk of spontaneous termination of pregnancy(occurs as a result of partial placental abruption; accompanied by increased tone in the uterine area, systematic bleeding and lack of nutrients).
- Decreased blood pressure (accompanied by headaches, dizziness, fatigue).
- Anemia (caused by blood loss; is the root cause of hemorrhagic shock).
- Incorrect attachment of the embryo (response to insufficient space in the lower part of the organ).
- and risk delayed development child (impaired blood flow causes a limitation in the oxygen volume and nutrients supplied to the fetus).
- The risk of placental displacement during natural labor with the impossibility of normal delivery.
The low location determines the importance of systematic monitoring of the course of pregnancy.
Caesarean section for pathology
C-section in case of placenta previa it is carried out if there is:
- anamnesis in the form of diseases with a pronounced inflammatory nature;
- detection of polycystic disease or uterine fibroids;
- previous abortive interruption of the gestation period;
- multiple births;
- pregnancy at a late age;
- early surgical intervention with violation of the integrity of the uterus;
- systematic blood loss in a volume exceeding 0.2 l;
- complete low location of the amniotic sac;
- leg or pelvic fetal position.
The above aspects serve as the basis for planned surgical intervention. If there are no indications for a cesarean section with placenta previa, natural delivery occurs. If there is a threat to the life of the expectant mother or child, emergency intervention.
Note! It should be remembered that after surgery a woman still has the possibility of subsequent childbearing.
Useful video: types of placenta previa
Conclusion
The gestation period may be accompanied by various anomalies. One of these pathologies is the placental location. This condition is diagnosed through a vaginal examination. Timely detection of pathology allows you to choose the optimal method of delivery.
For the full development of the baby, who “lives” in the mother’s tummy during pregnancy, a mandatory supply of oxygen and nutrients is required. The placenta is directly involved in this.
What is this?
Placental tissue is a special specific organ that appears in the female body only during pregnancy. It begins to actively function by the beginning of the second trimester and persists until childbirth. The main function of the placenta is to protect the child from environmental influences, as well as to participate in providing the blood flow necessary for its growth and development.
The placental tissue contains many different blood vessels, through which important substances enter the fetal body. The intensity of the placenta largely depends on the structure of the placenta and where it is located. intrauterine development fetus
Maternal part of the placenta
Typically, placental tissue forms in the immediate vicinity of the implantation site of the fertilized egg. In most pregnancies, implantation occurs in the upper part of the uterus - its fundus. As a rule, the fertilized egg attaches to the back wall, where the best blood flow occurs. However, this situation is not always possible. Sometimes it happens that the attachment of a fertilized egg occurs much lower - in the lower parts of the uterus. In this case, placental tissue is formed and is located quite close to the internal uterine os.
If the distance between the pharynx and the placenta is greatly reduced, then this clinical condition is called low position. This can be very dangerous as the pregnancy usually worsens.
If the placental tissue “enters” the area of the internal uterine pharynx, then this pathology is called presentation. In order to assess the presence of this pathology, doctors must evaluate the distance between the internal uterine os and the placenta itself. In each stage of pregnancy, the norm of this indicator is different. In the second trimester, the placenta should normally be 5 cm above the uterine os. In the third trimester, this value increases to 7 cm.
Presentation may vary. Doctors use special classifications that include several clinical options. One of the rather unfavorable options is complete placenta previa. In this case, almost all the placental tissue covers the uterine os. In this situation, the placenta is located critically low in relation to the external female genitalia. In this case, the risk of developing unfavorable complications during pregnancy increases many times over.
Causes
A variety of causative factors can lead to the development of complete presentation. Most often this pathology is caused by chronic diseases female genital organs. Pathologies that occur with the development of constant inflammation are accompanied by damage to the internal mucous membrane of the uterus. Changes in the structure of the mucosa contribute to the fact that the fertilized egg simply cannot attach to the uterine wall in the area of its bottom. It begins to descend into the underlying sections, which leads to the formation of placenta previa.
One of the predisposing factors in the development of this pathology may be previous surgical operations on the reproductive organs. Curettage of the uterine walls, removal of myomatous nodes and various neoplasms are risk factors for the development of placenta previa. Doctors note that this pathology is more common in women who give birth to their second and subsequent babies.
Typically, the likelihood of developing placenta previa in a subsequent pregnancy is slightly higher in women who have previously had a cesarean section. Existing scars on the uterus that have arisen after gynecological operations can also lead to the development of presentation.
How to identify?
Currently, it is quite simple to establish the localization of the placenta. Both a routine vaginal examination and an ultrasound test can help doctors with this. A more accurate method for diagnosing this pathology is, of course, ultrasound. Modern devices with which these examinations are carried out make it possible to calculate the distance between the placenta and the uterine os with an accuracy of a fraction of a centimeter. Complete placenta previa is a pathology that necessarily requires dynamic monitoring by doctors.
For this purpose, experts usually prescribe the expectant mother to undergo several ultrasound examinations at certain intervals.
To assess the location of the placenta in complete presentation, doctors most often use transabdominal ultrasound. Carrying out transvaginal examinations and vaginal examinations may be fraught with the development of bleeding.
If you cannot do without them, then in such a situation it is very important that the examinations are carried out by experienced and qualified specialists who will perform them as carefully and accurately as possible. The position of the placenta is also necessarily assessed immediately before birth.
Features of pregnancy development
Usually the first unpleasant signs appear in the 2nd trimester of pregnancy. With complete placenta previa, they can develop in the 3rd trimester, and also bother the woman almost until the very birth. In this case, it is important to monitor the well-being of the mother and child, and also to prevent possible dangerous conditions for their lives.
If future mom If you have placenta previa during pregnancy and feel a sharp deterioration in your condition, you should definitely see your obstetrician-gynecologist.
Complications
Pregnancy complicated by placenta previa often does not proceed entirely smoothly. Only in rare cases does carrying a baby not cause any discomfort to the expectant mother. As a rule, a pregnant woman experiences various complications that aggravate the course of pregnancy. The most dangerous of them are the following:
- development of bleeding from the genital tract;
- detachment of the placenta from the uterine wall;
- disruption of the intrauterine process of fetal development due to impaired blood flow through the uteroplacental vessels;
- development of fetal hypoxia.
These clinical conditions usually develop in combination. The severity of adverse symptoms largely depends on how severe the placenta previa is. With complete presentation, these symptoms develop quite often. The course of this pathology can be difficult to predict. A variety of reasons can lead to the development of complications.
Thus, bleeding from the genital tract can occur after lifting weights or engaging in intense physical activity. Even severe psycho-emotional stress can lead to a worsening of pregnancy.
Bleeding from the genital tract is one of the most common and unfavorable complications. Appearance of blood on underwear The expectant mother herself usually notices. Blood clots can have different colors: from dark brown to bright red.
During pregnancy complicated by complete placenta previa, it is very important to remember that if blood appears from the genital tract, you should immediately seek help. medical care. If the bleeding does not stop for several hours, and the pregnant woman’s well-being worsens, then in such a situation an emergency medical team should be called immediately.
The arriving doctor can assess the general condition of the expectant mother and, if necessary, refer her for hospitalization in a hospital.
While in the hospital, the expectant mother will receive treatment aimed at improving her well-being. At the same time, doctors will definitely evaluate the general condition of the fetus. If the threat to the life of the child is too great, and the gestational age is already sufficient for childbirth, then in such a situation, most likely, a decision will be made to urgently perform surgical obstetrics.
Frequent bleeding from the genital tract is dangerous for the development of an extremely unfavorable condition for the expectant mother and her baby - anemia. An anemic condition is characterized by a decrease in the amount of hemoglobin or red blood cells in the blood. Anemia has negative impact on the intensity of intrauterine development of the fetus, and also significantly worsens the general well-being of the pregnant woman. To compensate for any violations that have arisen, the expectant mother is prescribed medications
containing iron.
Hello, dear readers! Today I ask you to get serious. The topic is quite important and completely serious. However, any disturbances during pregnancy require attention. Mom’s tummy is like a cozy, warm nest, and it should have all the conditions for the baby’s life. But sometimes something goes wrong, and the baby becomes uncomfortable, he begins to literally suffocate. And one of the reasons is the incorrect location of the placenta.
This organ performs several tasks at once: provides nutrition to the baby, normal metabolism,... For all of these tasks to be performed successfully, the placenta must be positioned correctly. Today we’ll talk about such a problem as complete placenta previa, what this pathology threatens for mother and baby.
Where should the placenta be attached?
Do you know where the placenta should normally be located? Of course, on the back wall of the uterus. It is there that the baby is well protected from injury, and the blood supply flows especially well. But sometimes the placenta is attached in the wrong place. When it is in the lower part of the uterus, the gynecologist makes a diagnosis - presentation.
Today we will talk about its most dangerous type - complete presentation, when the placenta completely covers the internal os. Out of 1000 pregnant women, this problem occurs in only 2-3 women giving birth, but each of us needs to know about it, because no one is insured, and the consequences can be quite serious. U complete presentation is rare, so if you have been diagnosed with this pathology, this is a signal that not everything is in order with the body and you were not examined by a doctor when. Typically, presentation occurs due to diseases of the inner layer of the uterus (endometrium). It occurs due to surgical curettage, difficult previous births, removal of fibroids, cesarean section, endometriosis, inflammation of the cervix and many other reasons.
Complete placenta previa
Complete placenta previa may not manifest itself in any way in the first half of pregnancy, but in the second half it will show itself in all its glory. The uterus begins to actively contract closer to childbirth, and the placenta is not able to intensively stretch along with the uterus. It peels off and bleeds. Don’t worry, the child is not in danger of blood loss, but oxygen starvation is very possible.
Part of the placenta has detached and does not participate in gas exchange, which means that the baby receives less air.
Therefore, if, God forbid, you see blood, immediately call an ambulance and go to an appointment with a gynecologist. Typically, when presenting, bleeding begins after sexual intercourse, physical (even minor) exertion, a coughing fit, taking a hot bath or visiting a sauna, as well as with high intra-abdominal pressure.
Oddly enough, you will not feel any pain. Even if the blood stops flowing on its own, it may appear the next day. Therefore, do not delay visiting the doctor. Frequent bleeding threatens mothers with anemia, or even miscarriage or premature birth!
The baby may die
It has been noticed that with complete presentation, the baby is positioned incorrectly in the uterus. Doctors identify pelvic, oblique or transverse presentation. This means that childbirth will be doubly difficult. However, in all cases of complete presentation, the mother is prohibited from giving birth on her own and is sent for a caesarean section at approximately the 38th week of pregnancy.
I don’t want to talk about bad outcomes, but in some cases the doctor sees on an ultrasound that the placenta has separated too much and tells the mother a terrible prognosis: “Most likely, your baby will die.” The doctor can draw this conclusion if he sees that the detachment has reached 1/3 of the total area of the organ.
Complete placenta previa: bearing under control
Throughout the pregnancy, the expectant mother with a presentation should be under special medical supervision.
For the first half of the term, up to 24 weeks, she is allowed to be at home, but go to the doctor for examination. The woman will definitely spend the second half in the hospital. This is for her own safety. Suddenly, severe bleeding that begins, for example, at night, may not be immediately noticed, and, God forbid, you may lose your child.
In a hospital setting, the mother is not only always under observation, but also receives the necessary medications and minerals to replenish placental insufficiency and prevent anemia.
Unfortunately, for mothers with this pathology, there are a number of restrictions, and pregnancy for some of them may not seem like the most wonderful months of their lives. But for the safety of the baby and your own health, you need to take care of yourself:
- from sexual intercourse (especially intense) Sex tones the uterus and causes bleeding
- from physical activity
- from poor nutrition
- from crowded places where you may be pushed or infected with any infection
- from stress
- from long trips.
Your doctor should always be within reach to help you when needed.
Complete presentation is not a death sentence, but a real threat to the health and life of the baby. Take care of yourself, visit your gynecologist more often and let your pregnancy be pleasant and easy. Write your reviews, comments and questions to our forum. I’ll be happy to chat with you there too!
