Causes of placenta previa
Most often, complete placenta previa occurs in women who have already given birth. Doctors name two groups of factors responsible for malpresentation placenta: the woman’s health condition and impaired implantation of the fertilized egg when it attaches to the lower parts of the uterus.
Women at risk include:
- endometriosis;
- isthmic-cervical insufficiency and inflammation of the cervix;
- uterine fibroids;
- previous operations on the uterus;
- previous abortions, curettage;
- hormonal disorders menstrual cycle;
- pathology of uterine development.
Placenta previa - diagnosis
Full presentation placenta can be suspected by repeated painless bleeding from the genital tract. They appear suddenly and can be abundant. In this case, you need to immediately call an ambulance and remain completely calm until it arrives.
As a rule, a pregnant woman is hospitalized. In the hospital, the doctor conducts an external examination and refers you to an ultrasound. If ultrasound confirms the presence of complete placenta previa, then vaginal examination cannot be performed due to the high risk of further placental abruption and bleeding.
How to treat placenta previa?
If placenta previa is detected during a screening ultrasound in the first half of pregnancy and there is no bleeding, the woman can stay at home, observing complete rest, including sexual rest. If the pregnancy is 24 weeks or more, you need to go to the hospital and stay there until delivery, even if the bleeding has stopped. They try to maintain pregnancy until 37-38 weeks.
The only way of delivery with complete placenta previa is a cesarean section, since the placenta completely covers the cervical os. An emergency caesarean section is performed if the mother's life is in danger.
One of the most important factors The normal course of pregnancy is the correct development and location of the placenta, as the main nutritional organ of the baby in the womb. The normal course of pregnancy involves the attachment of the placenta in the fundus or on back wall uterus, that is, precisely in the places of best blood supply to the walls. In rare cases, the placenta may be located on the anterior wall of the uterus. This area is not the most suitable, because during pregnancy it undergoes much greater changes than the back. Moreover, the location of the placenta on the posterior wall provides protection from accidental injury.
Placenta previa is called pathological condition, characterized by its improper attachment to the wall of the uterus near the internal uterine os, that is, in its lower part. Presentation is classified as low, partial and complete. With low presentation, the lower edge of the placenta is no more than 6 cm from the internal os of the uterus. With a complete (central) presentation, the uterine os is completely closed. Fortunately, this condition occurs in no more than 1% of pregnant women. Partial or incomplete placenta previa can be lateral or marginal. In this condition, the cervical pharynx is closed by 1/3.
Speaking about the types of placenta previa, it is worth noting that the concepts of “ posterior presentation placenta,” which is so often mentioned in discussions on various forums, does not exist, because its posterior and anterior presentation is the norm. But it’s worth understanding the reasons for the above-described presentations and methods of treating them.
The reasons for improper attachment of the placenta may depend both on the condition of the woman’s body and on the characteristics of the fertilized egg. Attached ovum in a place with the most favorable conditions, and predisposing factors for presentation may be:
- scars after uterine surgery or abortion;
- chronic inflammation (endometritis);
- uterine fibroids (benign tumor);
- abnormalities or underdevelopment of the uterus;
- age over 35 years;
- multiple births.
The main symptom of previa is bleeding. Placental tissue is not able to stretch, and therefore, when the uterus stretches, the placenta begins to exfoliate, which causes bleeding. These bleedings appear suddenly, without pain, and can also suddenly stop, only to occur again after a while. Most often, such bleeding occurs in the third trimester when the uterus contracts, or during childbirth, when the cervix opens, although it can also be observed during the period from 16 to 18 weeks of pregnancy. Moreover, the lower the placenta is located, the more abundant and earlier the bleeding appears. Placental bleeding can be provoked either by lifting weights or intra-abdominal pressure during constipation, or by visiting a sauna or hot bath.
The second most important symptom of placenta previa is fetal hypoxia. The part of the placenta that has been detached does not participate in the uteroplacental circulation, which means that the degree of hypoxia will depend on the area of the detachment.
The main complication of placenta previa is the threat of miscarriage. In addition, hypotension (low blood pressure) appears, and due to blood loss, the pregnant woman develops anemia. All this negatively affects the development of the fetus and makes it impossible for a child to be born without surgery.
If a pregnant woman is regularly seen by a gynecologist, then diagnosing placenta previa is not difficult. Using ultrasound, placental migration can be easily monitored throughout pregnancy.
Treatment of placenta previa beyond 24 weeks of pregnancy occurs only in a hospital. The expectant mother is prescribed strict bed rest and medications that improve blood circulation and reduce the tone of the uterus, and in the presence of anemia, medications that increase hemoglobin are prescribed. If there is no bleeding, the woman can stay at home, but must follow a gentle regimen: avoid emotional and physical stress and avoid sexual intercourse.
With the onset of pregnancy, a woman must undergo an ultrasound examination. At the conclusion of this study, it is indicated how it is located in the uterus future baby and placenta. And if it talks about, then a woman has something to think about.
Briefly about placenta previa
The placenta is an organ in a woman’s body that appears only during pregnancy. It serves as a connecting link between the body of the expectant mother and her baby. The placenta provides nutrition to the fetus and its respiration, and removes metabolic products. Placental tissue also produces hormones that are necessary for the healthy course and development of pregnancy.
Normally, the placenta is located at the bottom of the uterus - that part of it that remains almost unchanged. If this organ is located on the side of the pharynx, then doctors note presentation. Placenta previa is a pathology of its attachment and development in a place that does not ensure a healthy and optimal course of pregnancy. Presentation may be partial. In this case, the os of the uterus is covered by the placenta by a third or two thirds. Complete presentation is when the center of the placenta is completely aligned with the os of the uterus. It is also called central presentation. Medical statistics show that complete presentation is 5 times less common than incomplete presentation.
In the case of incomplete presentation, that is, lateral or marginal, there are chances of the placenta spontaneously shifting to the desired area closer to birth. In the case of complete (central) presentation, this option is completely excluded.
Causes of central placenta previa
What is the reason for this pathology of the location of the placenta? Sometimes it is due to the fact that the fertilized egg simply cannot attach in the right place due to damaged endometrium of the uterus, that is, anomalies. The reasons for such anomalies are as follows:
- Abortion.
- Endometrial deformation as a consequence inflammatory diseases. These are scars and disorders of secretory function, fibroids.
- Atrophy of the endometrium of the uterus.
- Impaired blood supply to the uterus due to disease of cardio-vascular system, kidneys, liver.
These reasons make it clear why complete presentation is diagnosed more often in multiparous women than in the first pregnancy. Diseases of the body and genital organs precisely contribute to the occurrence of central placenta previa.
Another reason for such placenta previa may be a delay in the development of the fertilized egg. Then it does not reach the bottom of the uterus and is attached in the area of the pharynx. There the placenta begins to develop.
What are the symptoms and complications of central presentation?
Perhaps the most common symptom of central presentation is vaginal bleeding. This is a complication of placenta previa and its main symptom.
If the presentation is complete, then bleeding usually begins in the second trimester, it occurs periodically and lasts until childbirth. Indeed, as the gestational age increases, the placenta literally fuses with the uterus. The fetus develops, the uterus enlarges, and this is especially noticeable in its lower part - the place where the placenta is attached. Since the placental tissue is almost inelastic, it does not have time and cannot stretch behind the rapidly growing uterus. Therefore, partial placental abruption occurs. The vessels begin to bleed, the contents flow out of the genital tract through bleeding. Sometimes it gives way to spotting. As a rule, this happens the first time when a woman is sleeping or just lying down. However, she does not experience pain at all. This is the distinguishing feature of such bleeding from bleeding during a miscarriage, when severe cramping pain in the lower abdomen is bothersome.
If such bleeding, as a complication of presentation, occurs at 30 weeks, then it can be caused by sex or physical activity, sometimes by an examination by a gynecologist.
Symptoms of complete (central) presentation may include pain in the lower abdomen, lower back, low blood pressure, and uterine tone. Hypotension can be expressed in weakness and drowsiness, dizziness.
When bleeding occurs as a complication of breech presentation, the pregnant woman develops anemia. This is something that negatively affects both the woman and her unborn baby. A lack of oxygen in the blood of the expectant mother is fraught with delayed development of the fetus and stunted growth. Very often, such children suffer from anemia after birth.
If the expectant mother’s hemoglobin level drops, the gynecologist will prescribe appropriate treatment. But mommy herself can take adequate measures. This is the additional consumption of iron-rich foods. Among them are liver and pomegranates, peaches and apricots, blueberries and blueberries, black currants and cranberries. Among vegetables rich in iron are tomatoes and beets, pumpkin and spinach, and among cereals - buckwheat. You can eat walnuts and dark chocolate, but with caution, since these products are very high in calories and allergenic. Nutritionists also advise taking it together with vitamin C (ascorbic acid) to improve the absorption of iron. These are citrus fruits and broccoli, cranberries and pineapple.
Associated complications of central placenta previa
Central presentation can also provoke the following pregnancy complications:
- Premature placental abruption.
- Premature rupture of membranes.
- The likelihood of abnormal placement of the fetus in the uterus. It can be transverse, oblique, pelvic.
- Placenta accreta. In this case, she cannot separate from the uterus on her own during childbirth. Doctors separate it manually. Of course, this can cause heavy bleeding. Then the only thing the right way The solution to the situation is to cut out the uterus.
Diagnosis and treatment of central placenta previa
This presentation is usually diagnosed by ultrasound. However, it can also be determined during a routine gynecological examination.
As for the treatment of complete placenta previa, there is no medical treatment with drugs. Doctors can only monitor the condition of a pregnant woman and monitor changes in well-being. In this situation, gynecologists also keep other diseases of the woman under control, since many factors can contribute to the complication of the pathology. When a pregnant woman with a central presentation is not bothered by bleeding, the doctor can monitor her condition on an outpatient basis.
If the situation is not entirely calm and the woman feels symptoms of presentation, then she is advised to stay in the hospital from the 24th week of pregnancy. Usually she stays there until the birth itself in order to avoid any complications and force majeure.
Such a mother is prescribed bed rest, restorative medications and iron supplements, and medications that relieve uterine tone. Doctors try to prolong the pregnancy until the baby can be delivered.
Rules of conduct for a pregnant woman with central placenta previa
In addition to medical prescriptions, the expectant mother herself must behave in such a way as not to in any way provoke complications with her behavior. This means, physical activity there should be a minimum. A woman should not do any heavy lifting. You should not make sudden movements that displace the uterus. After all, this is fraught with placental abruption.
More oxygen can be absorbed on walks, if bed rest is not prescribed.
No stress, worries or nerves! All this can tone the uterus and provoke bleeding.
You need to eat foods rich in iron every day.
If a woman is not in a hospital, she should avoid crowded places such as public transport, market, so that she would not be pushed or hit by accident. And you can get infected with anything in a crowd. Especially during periods of seasonal flu and.
You should not travel anywhere so that if bleeding occurs or your health worsens, you can immediately contact a supervising doctor.
Childbirth with central placenta previa
The main problem of delivery with placenta previa of any kind is the high chance of bleeding.
Central presentation doesn't even suggest chances natural birth, since the placental tissue completely blocks the baby’s access to the birth canal.
Typically, a caesarean section for placenta previa is performed at 38 weeks if the woman is in satisfactory health. When a pregnant woman experiences heavy bleeding, a cesarean section is performed urgently.
If the operation went well, then the risk of complications, that is, bleeding after it, cannot be excluded.
Especially for Elena TOLOCHIK
Placenta or children's place is the basis for the full development of the fetus until birth. Normally, this important organ should be attached near the fundus of the uterus. But in some cases, the placenta is attached next to her cervix, completely blocking the path to the birth of a new life. This phenomenon is called complete placenta previa.
General characteristics of the placenta
In order to understand how dangerous complete presentation is, you need to understand the role of the placenta and the mechanism of its interaction with the body of the child and mother.
Placental tissue is permeated with so-called villi or small vessels. They practically merge with the uterus at the place where the placenta is attached to it. This is necessary to ensure metabolism between mother and child. The baby receives nutrition and oxygen from the mother’s blood through the umbilical cord, and waste substances are released through the placenta.
The fetus develops and grows, and the uterus grows with it. It increases in size from a matchbox to a “bag” 35 centimeters high. The walls of the uterus are very elastic and can stretch freely. This is especially evident in its lower part, where the neck is located. The placenta is far from being so pliable and stretchable.
If a pregnant woman has a complete central placenta previa, then the enlarging uterus “pulls” the placenta with it, and it does not have time to stretch behind it, since it is not designed for such a significant increase in size. In medical terms, the migration of the placenta with complete presentation is slow compared to the uterus. As a result, it detaches from the wall of the uterus.
Causes
Experts believe that all causes can be divided into 2 categories - uterine and fetal.
Uterine
The occurrence of problems of this kind is due to the fact that the fertilized egg, due to endometrial abnormalities, is attached to the uterus in the wrong place where it is supposed to be.
Endometrial defects are observed for many reasons, the main ones being:
- Previously performed instrumental abortions, including spontaneous ones, with trauma to the mucous membrane.
- Previous inflammations or diseases that caused deformation of the uterus - scars, fibroids, secretory disorders.
- Atrophy of the mucous membrane.
- Endometriosis.
- Pathology of uterine development.
- Deterioration of blood supply to the uterus due to chronic diseases liver, kidneys and cardiovascular system.
The above factors are in most cases observed in women with repeated pregnancies. This is caused by the accumulation of health problems in this category of pregnant women compared to first-time mothers.
Fetal
It does not have time to implant on the uterine endometrium in time, and as a result, it is located not at the bottom of the uterus, but near its cervix. This is where the placenta is laid. The probability that in the future it will completely close the uterine os is in this case almost 100%.
Why is it dangerous?
Deviations that occur with complete placenta previa.
- Bloody discharge and bleeding caused by rupture of the placenta with the uterus. They appear in the middle of pregnancy. These bleedings are always external, without internal hematomas, usually painless and sudden, most often starting at night. They are often provoked by physical activity, examination by a gynecologist, or even a severe cough. Sex life with complete placenta previa (to avoid increased bleeding), it is advisable to minimize or completely abandon it already at 25 weeks.
- Anemia or low maternal hemoglobin levels caused by frequent bleeding.
- Hypotension, which is accompanied by weakness, fatigue, headaches and even fainting.
- Fetal hypoxia, which can cause developmental delays, low birth weight, anemia in the first year of life, and weak immunity.
- Increased tone of the uterus, pain in the lower abdomen and lower back, which can threaten miscarriage.
- Incorrect position of the fetus (transverse, gluteal or oblique). Together with complete or partial blocking of the uterine pharynx, this makes the natural course of labor impossible. Without caesarean section in this case it simply cannot be done.
- Postpartum inflammation of the uterus due to difficult labor and low resistance of the mother to infections.
Diagnostics
Recognition and diagnosis of complete presentation for further monitoring of the progress of placental migration can be carried out already at the beginning of the second trimester of pregnancy. It is based on complaints about periodically appearing painless bleeding.
Using ultrasound, you can determine the position of the fetus. The low-lying placenta does not allow him to descend into the lower part of the uterus. Therefore, both on ultrasound and during examination, you can find that the presenting part of the baby is located above the entrance to the small pelvis. These data allow you to diagnose pathology.
Ultrasound helps (with a small degree of error) to monitor the location and movements of the placenta. In case of complete presentation, this procedure is specifically prescribed to be carried out three times at 16, 25 and 35 weeks.
If this examination does not reveal deviations in the location of the placenta, then it is necessary to look for other causes of bleeding. These may be pathologies in the lower parts of the birth canal.
Presentation forms
Placenta previa is often diagnosed in the first half of pregnancy. The following forms of presentation are distinguished.
- Central- the most dangerous of forms. It gives virtually no chance of further improvement in the situation and migration of the placenta to a safe distance in relation to the birth canal.
- Partial, when 2/3 of the pharynx is blocked by the back wall, there is a small chance that the situation will improve in the future.
- Regional. With this form of presentation, the obstruction is about 1/3 of the cervix. In this case, usually only a small proportion of pregnancies end with surgery. The baby's place then independently moves away from the pharynx and childbirth takes place naturally. Moreover, the question of whether marginal placenta previa can become complete should not bother future mothers in this case. They can count on a favorable pregnancy.
- Complete placenta previa along the posterior wall of the uterus- the normal and safest position for mother and baby.
- Complete placenta previa along the anterior wall happens much less frequently, but this is also not a pathology, but a variant of the norm. Mommy should only listen to the advice of specialists, then everything will be fine with her and the baby.
Treatment
A woman diagnosed with breech presentation should be under close supervision by her attending physician. For adequate medical control to the expectant mother Regular blood tests are prescribed. If hemoglobin dynamics are negative and a decrease in blood clotting is detected, iron supplements are prescribed, since the risk of anemia and bleeding is very high.
Means are also needed to improve the blood supply to the fetus. These are Ascorutin, Curantil, vitamin E, folic acid, Trental, Sorbifer, Ferrum Lek and others.
At bloody discharge Patients with this diagnosis are observed in the hospital for more than 24 weeks. Even if bleeding stops, constant monitoring continues until delivery.
If the condition of a pregnant woman with this diagnosis is satisfactory, she is prescribed bed rest, medications to reduce the tone of the uterus and general restoratives - Ginipral, No-shpa, Papaverine, vitamins. In addition, sedatives are prescribed - valerian root, motherwort and others. Laxatives are strictly contraindicated for pregnant women.
If bleeding continues, then injections of magnesia, Magne B6 and other drugs are also prescribed. In case of intense and prolonged bleeding, they are sent to the intensive care unit or intensive care unit.
Childbirth with a similar diagnosis
At 38 weeks, pregnant women diagnosed with placenta previa undergo a planned cesarean section. In this case, waiting for a natural birth is dangerous due to the high risk of bleeding due to placental abruption.
Caesarean section is indicated for more than 70% of women diagnosed with complete placenta previa.
It is used for:
- Central presentation.
- Incomplete with abnormal positioning of the fetus.
- Scars on the uterus.
- Multiple or polyhydramnios pregnancy.
- Narrow pelvis.
- First birth over 30 years of age.
- Additional risks associated with previous pregnancy terminations or uterine surgeries.
- Constant and extensive bleeding.
With other forms of breech presentation, labor can proceed naturally, but to avoid complications, the maternity hospital must have a pediatric intensive care unit and an operating room ready for an emergency cesarean section. The following circumstances are favorable for natural delivery:
- Absence of bleeding or its cessation after puncture of the amniotic sac.
- Clear signs of readiness of the pharynx for childbirth.
- Normal course of contractions.
- Correct fetal position.
Labor is not induced in this case. The amniotic sac is punctured when the cervix dilates slightly on its own. But if the bleeding increases, then they resort to urgent surgery.
After labor is completed (even if it took place physiologically), the woman in labor remains under observation. She may continue to bleed for a long time due to reduced contractility of the uterus at the site of its fusion with the placenta. Anemia and hypotension also aggravate the postpartum condition.
When presenting, the baby's place often cannot spontaneously and completely detach from the body of the uterus, so after the examination it is necessary to perform an operation under anesthesia to separate the placenta. In the rarest cases, bleeding after a cesarean section cannot be stopped, and in order to save the woman in labor, the uterus has to be removed.
Complete placenta previa is not a death sentence for motherhood, but only a warning to carefully follow all the specialist’s recommendations, serious preparation for childbirth and a subsequent gentle recovery regimen for the young mother.
