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 it observed full presentation 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, ovum under the influence of gravity it sinks lower and lower until it finally “finds” a place where it can gain a foothold. 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;
operations (abortion, caesarean 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?
Located in such an unfortunate way, 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;
gynecological examination;
bath, sauna and hot tub.
There is usually no pain; bleeding often begins and ends suddenly for the pregnant woman. It can be either scanty (spotting) or 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 natural birth 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 caesarean section.
Also, a caesarean section is performed in the presence of scars on the uterus, multiple pregnancies and abnormal position of the 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
If you have placenta previa, it means that your placenta is located abnormally low in the uterus, near or blocking the opening of the cervix (internal os). The placenta is a disc-like organ that is usually located at the top of the uterus and provides nutrients to the baby through the umbilical cord.
If breech is discovered early in pregnancy, it is usually not considered a problem. But if the placenta remains too close to the cervix and for more later, then this can cause serious bleeding, which leads to other complications of pregnancy and often becomes. If the presentation persists until the end of pregnancy, then childbirth is carried out by cesarean section.
If the placenta completely covers the cervix, it is called full presentation . If it is in close proximity to the cervix, it is called incomplete presentation . You may also hear the term " partial presentation ", which characterizes the condition when the placenta covers only part of the cervix of the internal os. If the edge of the placenta is within two centimeters of the internal os, but does not border it, it is called low placental attachment (or low placentation).
The location of the placenta is usually checked at 16 to 20 weeks, during a second routine fetal ultrasound, and, if necessary, later during subsequent ultrasound examinations.
Risk factors for the development of placental presentation
Most women who develop it have no obvious risk factors. But if the expectant mother has one of the following factors, then she is likely to develop this complication:
- the presence of placenta previa during a previous pregnancy;
- having had a cesarean section in the past (the more cesareans, the higher the risk);
- having had uterine surgery (such as uterine cleansing or);
- multiple pregnancy;
- , drug use;
- pregnancy in mature age, especially it concerns ;
- if a woman already has several children (the more children, the higher the risk).
Management of pregnancy with placental presentation
Management of such a pregnancy primarily depends on its duration. Don't panic if a mid-pregnancy ultrasound shows that you have placenta previa. As your pregnancy progresses, the placenta may migrate further away from the cervix and breech will no longer be a problem. During your third trimester ultrasound, your doctor will recheck the location of your placenta.
Only a small percentage of women who are diagnosed low placentation, this condition persists until childbirth. Usually during the third ultrasound the placenta is found to be in its normal position. But there is one “but”: if placenta previa is complete, then it will most likely remain that way. The tendency of the placenta to “migrate” is noted only with incomplete (partial) presentation and low placentation. In general, during childbirth it occurs in one case out of 200 births.
If a third trimester ultrasound shows that the placenta is still obstructing or is too close to the internal os, the woman is not advised to undergo internal gynecological examinations and taking swabs from cervical canal. In addition, she needs to calm down and avoid any activities that can provoke vaginal bleeding, such as housework, heavy physical labor (including carrying heavy bags of groceries!), and she is also contraindicated in exercising.
When the time comes to give birth, the woman will have a caesarean section. In a complete presentation, the placenta blocks the baby from leaving the uterus. And even if the placenta only partially covers or borders the exit of the uterus, the woman still needs to have a C-section because in most cases the placenta begins to bleed as the cervix dilates.
It is likely that against the background placental presentation A woman in her third trimester may experience painless vaginal bleeding. In such cases, especially if the bleeding is accompanied by spasmodic contractions of the uterus, the woman should be hospitalized. Bleeding occurs when the cervix begins to open slightly, and during its expansion, the blood vessels in the cervix are injured. If the baby is almost full-term, the woman will immediately undergo a cesarean section.
If the child is still very early to be born, then a cesarean section will be performed only if the child’s condition requires immediate delivery, or if the woman has severe bleeding that cannot be stopped. If the condition is stable, then future mom will be observed in the hospital until the bleeding stops. If the pregnancy is less than 34 weeks, she may be given corticosteroids to speed up the development of the baby's lungs in case the baby is born prematurely.
If the bleeding has stopped and does not return for at least a couple of days, and if both the expectant mother and her baby are in good condition, then the woman can be discharged home. In such cases, the woman is usually given a planned caesarean section at around 37 weeks, unless there is no reason for an earlier delivery.
Complications from placental presentation
Having placenta previa makes it more likely that a woman will bleed heavily and need a blood transfusion. This applies not only to pregnancy, but also to the birth process and the postpartum period. And that's why:
After the baby is removed from the uterus (by caesarean section), the obstetrician-gynecologist removes the placenta and the woman is given Oxytocin (and other drugs if necessary). Oxytocin causes uterine contractions, which help stop bleeding from the area where the placenta was implanted. But if a woman has placenta previa, then the placenta is implanted in the lower, rather than upper, part of the uterus, and uterine contractions in this case are not as effective in stopping bleeding.
In women with placental presentation very often it turns out that the placenta is implanted too deeply, and it is extremely difficult to separate it during childbirth. This is called placenta accreta. The accretion can cause massive bleeding and may require multiple blood transfusions during delivery. This can be life-threatening and may require a hysterectomy (removal of the uterus) to stop the bleeding. Finally, if a woman was forced to give birth for a long time ahead of schedule, her baby will be at risk of complications from premature birth, such as breathing problems and very low weight.
Placenta previa is a serious complication of pregnancy when the placenta is displaced into the lower segment of the uterus. And then part of the placenta or all of it turns out to be present in front of the head or pelvic end of the fetus. With a transverse position of the fetus, when its head lies to one side of the uterus, and the legs or pelvic end to the other. With this position of the fetus, there is nothing directly at the exit of the uterus or the fetal arms are flickering. And the placenta lies ahead...
This is facilitated, firstly, by the same sexually transmitted infections, STIs.
Chronic inflammation caused by these pathogens affects the inner lining of the uterus - the endometrium, making it defective; the fertilized egg cannot properly attach to any defective wall and ends up in the lower segment, where the endometrium is not so fatally damaged. The second reason may be a genetic defect of the embryo, the absence of an enzyme that dissolves the surface of the endometrium so that the fertilized egg gets into such a hole and “buries” under the endometrial defect. The fertilized egg without the enzyme also falls down, and by gravity falls into a hole made by itself in a not so thick endometrium of the lower segment.
Also, in the formation of placenta previa, defects in the structure of the uterus can be important, when the additional uterine horn has a poor endometrium, unsuitable for hooking the fetus to the egg. The embryo also ends up in the lower segment of the uterus. Or the presence of a myomatous node protruding into the uterine cavity makes the endometrium defective and the fertilized egg cannot attach.
Endometrial deficiency can also develop in women who have had abortions or uterine curettage before an existing pregnancy.
In a situation where the placenta lies in front of the head or pelvic end of the fetus, any episode of uterine tension during fetal movement, threat of miscarriage, or Braxton-Hicks contractions can displace the placenta and cause its detachment from the uterine wall. This occurs due to the fact that when the entire uterus is tense, the lower segment of the uterus does not tense or contract. Because of this, displacement and detachment of the placenta previa occur.
This can cause bleeding into the uterine cavity, impaired circulation of the fetus, and severe hypoxia - depletion of oxygen content in the body. Lack of qualified medical care in this acute situation can lead to fetal death and dangerous blood loss for the woman.
Fortunately, partial or even complete placenta previa diagnosed at 7-8 weeks or 20-21 weeks with subsequent ultrasound most often records a gradual “creeping” - migration of the placenta, with the growth of the uterus, away from the exit from the uterus, up the wall of the uterus. This happens when the placenta is predominantly located on the anterior wall of the uterus, because during pregnancy, it is mainly the anterior wall that grows and stretches. When the placenta is located on the posterior wall, the hope for placental migration is weakened, since the posterior wall grows to a much lesser extent.
The placenta has many functions during pregnancy - delivering nutrients and oxygen to your baby from your blood through the umbilical cord. Usually it is attached high walls uterus; but problems can arise if the placenta covers the cervix instead. This condition is called placenta previa.
Risk factors
Risk factors include the following:
- numerous births;
- previous cesarean section;
- pathology of the uterus that prevents normal implantation (uterine fibroids, previous curettage);
- smoking;
- multiple pregnancy;
- advanced age of the mother.
Which situation is normal?
During labor, the baby moves forward of the placenta, passing through the cervix and vagina. It's important that things happen this way because the baby needs the placenta to breathe until he can do it himself.
What situation is abnormal
If the placenta is low and partially or completely covers the cervix, which leads into the vagina. This occurs in about one in 200 cases. Women who have had multiple children, late births, smokers or those who have already had a caesarean section are at greater risk.
What to worry about
Placenta previa may increase the risk of life-threatening hemorrhage before and after birth. This heavy, uncontrollable bleeding can occur because while the cervix thins and dilates for labor, the connection between the placenta and uterus can rupture due to the placenta being improperly positioned. If this happens, you may experience painless bleeding. The doctor will do an ultrasound to find out the cause of the bleeding. An ultrasound at 18-20 weeks may show a low-lying or placenta previa. It will be done again in the 3rd trimester, when in most cases the placenta will not be as low due to the growth of the uterus. If it's still completely covering your cervix in the 3rd trimester, it's probably still there. The diagnosis of placenta previa is usually made during the last 2 months of pregnancy.
Placenta previa can be:
- complete (the placenta “lies” on the internal os of the cervix, completely blocking it);
- partial (part of the placenta extends onto the internal os of the cervix);
- low (the edge of the placenta is slightly higher than the internal os of the cervix).
Symptoms and signs of placenta previa during pregnancy
Signs of placenta previa usually appear as sudden, painless, heavy bleeding of bright red blood, sometimes leading to hemorrhagic shock.
In some pregnant women, bleeding is accompanied by contractions.
The main symptom of placenta previa is bleeding from the genitals in the second half of pregnancy, at 28-30 weeks. This occurs suddenly, for no apparent reason, in the absence of symptoms of a threatened miscarriage.
Such bleeding can be repeated until the end of pregnancy, they lead to anemia - anemia of pregnant women. It is advisable to carry out an ultrasound diagnosis after the first episode of bleeding, which will determine the presentation itself and its degree: complete, partial, marginal, etc. A woman with placenta previa should be hospitalized and stay in the maternity hospital until delivery. In the department of pregnant women, such women are prescribed strict bed rest and medications that relax muscles - antispasmodics. Anemia is also treated with vitamins and iron supplements. Such observation and treatment in a hospital provide the very qualified assistance to prevent life-threatening bleeding for the mother and fetus. The method of delivery is cesarean section, since during labor and uterine contractions, abruption can progress and lead to bleeding that is dangerous for both lives. Only with marginal placenta previa, when only a thin crescent of the marginal sinus of the placenta partially blocks the exit from the uterus, can you open the amniotic sac at the beginning of labor and lower the fetal head so that it presses against this edge, and thus prevent bleeding. This is only possible when the fetal head is positioned above the presenting part or the entire placenta. Placenta previa is very often combined with breech, transverse or oblique position of the fetus. In such cases, the only method of delivery is cesarean section.
There are partial and complete placenta previa. Presentation is called complete if the placental tissue completely covers the internal os of the cervix. There is a concept of low placentation - this is a condition intermediate between the normal location of the placenta and its presentation. In this case, the edge of the placenta is not located high enough from the internal os, below 7 cm from it.
Threats of placenta previa during pregnancy
In the first half of pregnancy, placental precipitation is observed more often than in the third trimester of pregnancy. This is because as pregnancy progresses, the placenta migrates upward. It rises with the growth of the uterus from the internal os and no longer threatens pregnancy.
But if this does not happen, placenta previa can lead to.
- the appearance of a threat of miscarriage and bleeding (a low-lying placenta can detach, which entails bleeding and death of the embryo);
- iron deficiency anemia of a pregnant woman (a low-lying placenta can provoke bleeding that deprives a woman of iron);
- chronic hypoxia and delayed fetal development (the poor placenta attachment site is less well supplied with blood, because of this the baby suffers from a deficiency of oxygen and nutrients);
- incorrect position of the fetus in the uterus (if the placenta lies on the internal os, it interferes with the normal insertion of the baby’s head into the pelvis).
A pregnant woman can guess about some change in her condition by bloody discharge from the genital tract is bright scarlet in color. They are usually not accompanied painful sensations, but can cause symptoms of hemorrhagic shock due to anemia in the pregnant woman. The child’s condition depends on the amount of blood loss, since with heavy bleeding he experiences acute hypoxia (oxygen starvation).
Causes of placenta previa during pregnancy
Causes of placenta previa:
- the presence of abortions and uterine curettage before a real pregnancy. Intrauterine interventions lead to damage to the uterine mucosa and the occurrence of an inflammatory process. After inflammation, changes occur in it that do not allow the fertilized egg to penetrate the uterine wall (implantation) in the right place, so it sinks lower and attaches to the lower part of the uterus with the subsequent development of placenta previa;
- The presence of malformations of the uterus, sexual infantilism (underdevelopment of the internal genital organs), uterine fibroids, a scar on the uterus after a previous cesarean section or removal of fibroids - all these factors can interfere with the correct implantation of the fertilized egg;
- There is a violation of the ability of the fertilized egg to produce substances that facilitate its penetration into the wall of the uterus and fixation in it. In this case, the fertilized egg either produces an insufficient amount of special enzymes that help melt the mucous membrane of the uterus, or the production of these substances begins with a delay, when the fertilized egg has already descended into the lower part of the uterus.
It must be remembered that as pregnancy progresses, the placenta is able to move upward along the uterine wall. The anterior wall stretches as the uterus grows, and the placenta is pulled along with it towards the fundus of the uterus (migrates). If the placenta is located on the back wall of the uterus, then there is little hope of its moving upward due to the slight stretching of this part of the uterus during pregnancy. Thus, if the diagnosis of placenta previa is made at a short period of time (up to 25 weeks; pregnancy and the placenta is located in the front, then most likely by the time of delivery its location will be normal.
Placental abruption occurs as a result of minor uterine contractions (Braxton-Hicks contractions) that begin during pregnancy, serve to prepare the uterus for childbirth and are practically not felt by the pregnant woman. At the site of placental abruption, the vessels of the placental area of the uterus are exposed, from which bleeding begins. Most often it occurs during pregnancy 28-30 weeks. Bleeding usually begins for no apparent reason, when the woman feels well. Its duration and the amount of blood loss are individual and do not depend on the degree of placenta previa (complete or partial). Bleeding with placenta previa most often recurs regularly throughout the rest of the pregnancy. They, even if not very abundant, due to their recurrence, lead to the development of anemia in a pregnant woman (a decrease in the content of red blood cells and hemoglobin in the blood). Severe anemia can cause fetal development problems. Repeated blood loss also leads to the fact that even minor bleeding during childbirth can cause a threat to a woman’s life.
An incorrectly positioned placenta prevents the presenting part of the fetus (head) from positioning correctly in the uterus. Very often there is a combination of placenta previa with incorrect provisions fetus: breech presentation, transverse or oblique position.
The diagnosis of placenta previa is made on the basis of ultrasound examination, as well as according to vaginal examination (in a hospital setting).
Diagnosis of placenta previa during pregnancy
Transvaginal ultrasound. Placenta previa should be considered in all women with bleeding after 20 weeks. If there is a presentation, manual vaginal examination may increase bleeding or cause sudden heavy bleeding; therefore, if bleeding occurs after 20 weeks, such a study is contraindicated unless placenta previa is excluded by ultrasound. Sometimes presentation cannot be differentiated from abruption otherwise than with ultrasound.
Fetal cardiac activity should be monitored in all women suspected of having symptomatic placenta previa. If the clinical situation is not urgent, at 36 weeks the amniotic fluid is examined to determine the degree of maturity of the fetal lungs in order to determine the feasibility of delivery.
Treatment of placenta previa during pregnancy
- Hospitalization and bed rest for the first episode of bleeding before 36 weeks of gestation.
- Delivery if the condition of the mother or fetus is unstable.
For the first (signal) episode of vaginal bleeding before 36 weeks, treatment consists of hospitalization, bed rest and sexual rest, because sexual intercourse may cause bleeding due to uterine contractions or direct trauma. After the bleeding stops, discharge for outpatient observation is possible.
Some experts recommend the use of corticosteroids to speed up lung maturation because... may require urgent delivery at term<34 нед. При повторном кровотечении пациентку снова госпитализируют и наблюдают до родоразрешения.
Delivery is indicated in the following cases:
- heavy or uncontrollable bleeding;
- unsatisfactory results of monitoring fetal cardiac activity;
- hemodynamic instability in the mother; maturity of the fetal lungs (usually at 36 weeks).
Delivery is almost always done by caesarean section, but vaginal delivery is also possible if the fetal head is firmly attached and labor has already begun, or if the gestational age is less than 23 weeks and the fetus is expected to be delivered quickly.
Hemorrhagic shock should be treated. Rh0(D) immunoglobulin should be prescribed prophylactically if the mother has Rh-negative blood.
Women diagnosed with placenta previa should be hospitalized. In case of marginal placenta previa and the absence of uterine bleeding, it is considered best for the pregnant woman to stay in the hospital from the moment of diagnosis until delivery.
In case of complete placenta previa or marginal presentation and the presence of at least one episode of uterine bleeding, the presence of the pregnant woman in the hospital before birth is mandatory and vital.
Such pregnant women in the hospital are recommended to adhere to strict bed rest, antispasmodic drugs, multivitamins, and iron supplements are prescribed. The woman is under round-the-clock supervision by medical personnel; her blood pressure is regularly measured and laboratory blood tests are performed. In addition, after 32 weeks of pregnancy, a cardiotocographic examination of the fetus is performed (once a week) and an ultrasound examination of the uterus and fetus (once a month).
Currently, the main method of delivery for pregnant women with placenta previa is cesarean section. This is due to the fact that during labor pains placental abruption intensifies, bleeding also intensifies and can become profuse (massive), which will pose a threat to the life of the woman and child.
Treatment depends on the length of pregnancy, whether the placenta has begun to separate from the walls of the uterus, and the health of the baby. If placenta previa is diagnosed but there is no bleeding, you will likely be advised to have bed rest or activity restrictions to reduce the risk of bleeding until the baby is old enough for a caesarean section. If bleeding starts, you will be admitted to hospital; how long you stay there depends on several factors. In this case, a caesarean section is almost always done, because during a normal birth the placenta will tear away from the walls of the uterus, and bleeding will begin, dangerous for the mother and child.
A pregnant woman with bleeding should be hospitalized in a maternity hospital to provide timely medical care. The doctor compares data on bleeding, its volume, gestational age, ultrasound data and decides on the tactics of medical care for the woman. It is possible that the doctor will monitor the pregnant woman’s condition for some time, but may immediately suggest conservative treatment or surgical intervention (caesarean section).
In case of complete placenta previa (the placenta blocks the baby's exit from the uterus), in order to avoid massive bleeding in the woman and asphyxia of the fetus during childbirth, a planned cesarean section is indicated until the 38th week.
If the placenta is partially present, the woman may be allowed to go into natural labor, but only the maternity hospital doctor who is caring for the expectant mother can resolve such an issue.
Placenta previa is a dangerous situation for mother and baby, so it is necessary to follow all the recommendations of the treating obstetrician-gynecologist (exclusion of physical activity, exclusion of travel, exclusion of sexual activity, regular ultrasound examinations, hospitalization if necessary, etc.).
In the first weeks of pregnancy, the fetus is nourished through the enlarged layer of the endometrium.
The chorionic villi penetrate the loose mucous membrane of the uterus, densely permeated with blood vessels, and receive the necessary nutrients from there.
A full-fledged placenta is formed only by 10-12 weeks. From this point on, the doctor can determine its position by palpation or ultrasound examination.
There is practically no way to influence the course of formation of the placenta and the choice of its attachment site. This may be due to pathology of the villi, when the chorion is physically unable to gain a foothold and remain in the upper lobes of the uterus.
There are also some factors on the maternal side that, according to statistics, significantly increase the likelihood of the placenta being located in the lower segment of the uterus:
- frequent (or chronic) inflammatory processes of the endometrium and infections of the genital organs;
- congestion in the pelvis (due to chronic diseases of the mother);
- previous abortions;
- placenta previa in previous pregnancies;
- scar on the uterus;
- smoking;
- complicated previous births;
- abnormalities in the structure of the uterus.
All these reasons influence the formation of the uterine mucosa. If it is underdeveloped and the blood flow is weakened, then nature itself chooses a “convenient” place for feeding the fetus - the lower part of the uterine cavity. According to the laws of physics, the blood supply to this area will always be better than in the upper lobes.
Preventive measures, such as giving up bad habits, timely visits to the doctor and treatment of inflammatory diseases, adequate physical activity, and genital hygiene, significantly reduce the risk of such complications during pregnancy.
Diagnostics
If, during a routine examination at the end of the first trimester, the doctor suspects low placenta previa along the posterior wall, an ultrasound is prescribed.
Fixation of the placenta by 7 cm or less relative to the internal os for up to 26 weeks and by 5 cm in the 3rd trimester is called “low presentation”.
This pathology is the most harmless of all existing ones. With this arrangement, bleeding rarely occurs during pregnancy and childbirth. In addition, a low-lying placenta is prone to migration.
As the fetus grows, the uterus enlarges, stretches, and the place to which the placenta is attached may rise. With such a favorable outcome, presentation will not become an obstacle to natural childbirth.
The woman is closely monitored by a doctor for the entire period, undergoes tests and ultrasounds more often, and regularly receives medication that supports the placenta and prolongs the pregnancy.
The position of the placenta is monitored by ultrasound at 16, 25 and 34 weeks of pregnancy.
Depending on whether the placenta covers the cervix and where the central part of the baby’s place is located, doctors distinguish 4 degrees of presentation:
- the placenta is 3 cm from the internal os;
- the edge of the placenta has reached the cervix, but the internal os is not blocked;
- one of the edges of the placenta is attached to the opposite part of the lower segment of the uterus, the internal os is covered by part of the placenta;
- the center of the placenta is located on the internal os, and both of its parts are symmetrically located on opposite lobes of the uterus.
Presentation of the 3rd and 4th degrees is uncommon, less than 1% of the total number of births.
If the internal os is completely blocked, natural childbirth is impossible. But timely diagnosis allows mother and baby to be prepared in advance for a cesarean section and the birth of a healthy child.
Symptoms of low presentation
As a rule, until the 20th week of pregnancy, a low location of the placenta does not manifest itself in any way.
In case, you need to consult a doctor. But this is not yet a reason to panic!
Light red mucous or bloody discharge that is not accompanied by pain or may be a result of pressure on the vaginal wall and does not pose a threat to the unborn baby.
As a rule, physical activity, coughing and sneezing, constipation, and sexual intercourse can trigger the appearance of discharge.
In addition to bleeding, only 20% of pregnant women experience:
- headache;
- nausea;
- dizziness;
If a woman feels pain, hospitalization is necessary to assess the condition of the mother and fetus, and strict bed rest. In most cases, doctors manage to quickly cope with the situation. Perhaps the expectant mother will be able to return home before giving birth. Sometimes a woman is hospitalized with similar symptoms several times during pregnancy.
In the arsenal of modern doctors there are drugs that are safe for pregnant women to stop bleeding.
If necessary, additional therapy with iron and vitamin C supplements, or blood transfusion is carried out.
Why is it dangerous?
If at the beginning of pregnancy a presentation of 1-2 degrees was diagnosed, but until the 24-26th week of pregnancy the placenta has not changed its position, low presentation may lead to new complications.
The dangers that arise at the end of the second and beginning of the third trimester are associated with the pressure of the placenta itself and the growing fetus on the cervix. They can threaten the mother, baby or complicate the course of childbirth:
- recurrent bleeding can lead to;
- anemia causes hemorrhagic shock (threat to the life of the fetus);
- Possible deterioration of blood flow due to compression of blood vessels, and this leads to fetal hypoxia;
- (can also cause fetal hypoxia);
- low placentation may prevent the fetal head from descending into the pelvis. As a result, an incorrect (lateral) position of the fetus is diagnosed, and it is also possible. This makes natural childbirth difficult;
- Even when the birth canal is clear, the placenta can shift during contractions during natural childbirth and make it impossible. In this case, an emergency CS is performed;
- the location of the placenta on the anterior wall of the uterus can lead to large blood losses during the delivery operation. In this case, the CS is performed according to a special algorithm, which allows the baby to be born faster, and then provide the mother with the necessary therapy.
In case of heavy or recurrent bleeding, or intrauterine fetal hypoxia, the woman remains in the hospital until delivery.
By 36 weeks, after assessing fetal maturity, a cesarean section is prescribed. If necessary, delivery is carried out earlier.
What to do if you have been diagnosed with low placenta previa?
There are no medications that would change the position of the placenta to a safer one. But if a threat of fetal hypoxia is diagnosed, the doctor may prescribe drugs to improve blood circulation, additional vitamin complexes and antispasmodics to reduce the tone of the uterus.
If the pregnant woman feels well and is at home, we must not forget about preventing complications.
- The expectant mother should protect herself from stress and anxiety.
- It is advisable that someone close to you or a visiting assistant take on the housework.
- Constipation should be avoided
- Sexual contact is prohibited, as well as any vaginal procedures (douching, suppositories, etc.)
- You can't lift weights. If there is an older child, have someone help care for him.
- If possible, travel on public transport should be limited, especially during peak hours.
- If a woman’s condition allows, you can do swimming or gymnastics for pregnant women (after consultation with a doctor!) Special sets of exercises will make the ligaments more elastic, help strengthen the pelvic muscles, and relieve tension.
Low placenta previa during pregnancy can threaten the life of the mother and the health of the baby.
If you have been diagnosed with this, you must follow your doctor's recommendations with special care.
The expectant mother should avoid stressful situations, physical activity, avoid long trips, and limit sex life. Perhaps the baby will be born a little earlier than planned, but doctors will do everything possible to ensure that by this time the baby is healthy and viable.
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The quality of pregnancy, as well as the quality of labor, largely depends on the location of the placenta. Normally, it is attached to the front or back wall, closer to the fundus of the uterus.
But in approximately 1% of all pregnancies, it is discovered that the baby's place was implanted in an atypical place - too close to the internal os of the cervix. In such a situation, doctors talk about his presentation and raise the question of the advisability of natural delivery.
What it is? Placenta previa is a pregnancy pathology that involves the attachment of the placenta in such a way that it partially or completely blocks the exit to the cervical canal. Such localization of the child's place not only is an obstacle to normal labor, but also poses a threat to the life and health of the child and mother.
The main reason why the fertilized egg is implanted incorrectly is pathological changes in the structure of the endometrium of the uterus, which are caused by the following factors:
- Inflammatory diseases of the uterus, especially their chronic forms.
- Disorders of the structure of the endometrium and myometrium, in particular endometriosis, fibroids.
- Congenital anomalies of the uterine body (for example, bicornus)
- Mechanical trauma to the uterine cavity (curettage, history of cesarean section)
- Presence of multiple pregnancy.
- A history of more than 4 births.
Whatever the reason that leads to the pathology of the endometrial structure, the fertilized egg does not have the opportunity to implant into the wall of the uterus in time, and therefore attaches to the lower segment of the reproductive organ.
What are the dangers of placenta previa?
Currently, doctors are aware of the presentation by the end of the pregnancy, so most women undergo a caesarean section to avoid unnecessary risks associated with natural childbirth.
But if the expectant mother is not seen by a gynecologist and does not monitor the state of her pregnancy in any way, then with full presentation she has a high risk of dying if she allows birth naturally.
Placenta previa is also dangerous for the fetus. Starting from the second trimester, a woman may be bothered by periodic bleeding from the vagina, which is provoked by detachment of part of the baby's place.
- In addition, improper attachment of the placenta can cause hypoxia in the fetus and provoke premature birth.
Placenta previa during pregnancy does not go unnoticed either by the mother or by the attending physician. The first trimester can be relatively calm, but as the baby’s place matures and the size of the uterus increases, a woman may notice the following symptoms:
- Bloody issues. They are recurrent in nature and can appear suddenly, even if the patient is on bed rest.
- Anemia. It is a consequence of frequent bleeding.
- Exacerbation of STDs. Associated with a general weakening of the body’s defenses, which regularly experiences blood loss.
The studies complement the clinical picture characteristic of placenta previa. Tests, palpation and ultrasound examination will reveal the following signs of pathology:
- Fetal hypoxia
- Partial placental abruption
- Cervical smoothing
- Incorrect position of the fetus in the third trimester
- Presence of ascending genital tract infections
Already in the second trimester of pregnancy, it becomes clear whether the placenta will be previa, so if a woman is registered with a gynecologist, then by the time of birth doctors will try to minimize the risks for her and the baby.
Partial, low and central placenta previa
If the location of the baby's place is atypical, a caesarean section is not always indicated. If there are such types of localization of amniotic tissue, in which it is possible for a pregnant woman to have a natural birth.
Central placenta previa
Central placenta previa - sometimes called complete placenta previa. It involves absolute closure of the internal os of the cervix. This position of the child’s seat is observed in approximately 22–25% of cases of all presentations.
If the birth takes place naturally, then both mother and child will die, so in this case the only safe obstetrics service is a cesarean section, carried out before the end of the pregnancy (most often at 36 weeks).
Partial placenta previa
Partial placenta previa means that the internal cervical os is not completely blocked. Doctors distinguish two types of this pathology: lateral and marginal placenta previa (usually along the posterior wall).
- In the first case, the baby's place blocks approximately half of the cervical canal, and doctors do not always risk allowing such a pregnant woman to have a natural birth.
- In the second case, the baby's place blocks the cervical canal by a third - this makes it possible for normal delivery through the natural birth canal.
Low location of the placenta
Low location of the placenta - suggests that the baby's place is located at a distance of 5 - 6 cm to the internal os of the cervix. In some pregnant women, as the term increases, the membranes may stretch and end up close to the fundus of the uterus (this is the clinical picture that is observed normally).
This is one of the mildest forms of pathology, but medical supervision is still necessary, because low placenta previa during pregnancy threatens frequent bleeding and increased uterine tone.
Pregnancy management tactics
Atypical location of the baby's place is quite rare, but requires a special approach to managing such a pregnancy. From the moment the pathology is discovered, the expectant mother should visit the gynecologist not once every 14 days, but once a week.
In addition, she will have to take more tests and undergo more examinations. In order for the pregnancy to end successfully, the gynecologist needs to adhere to a certain technique.
- Palpation of the uterus outside a hospital setting is extremely undesirable. It can cause severe bleeding and subsequent anemia in the patient.
- Regular fetal cardiotocography (CTG) to exclude hypoxia, or to carry out timely medical measures if it is detected.
- Regular ultrasound examinations to monitor the condition of the placenta.
- Providing a pregnant woman with complete rest in a hospital setting at gestational ages from 30 weeks with severe bleeding.
The decision on how the birth will take place is made only by the doctor, without taking into account the opinion of the woman herself, since the situation obliges doctors to follow the path of reducing the risks of maternal and infant mortality.
Delivery with placenta previa
An atypical location of the baby's place may allow a natural birth, but only if the doctor did not see the potential risk of death for the mother and fetus. In all other cases, a caesarean section is performed.
Natural childbirth– possible with incomplete placenta previa and partial occlusion of the internal os of the cervix in the absence of significant bleeding.
Also, delivery through the genital tract can be carried out using special forceps in the presence of a dead fetus. But at the same time, the child must have either a pelvic or cephalic presentation.
C-section– indicated for complete occlusion of the cervical canal, partial occlusion, as well as in the presence of severe bleeding.
The dead fetus is also removed abdominally if its release through natural channels is dangerous for the life of the mother. In this case, the child's seat must be quickly separated manually.
Placenta previa - consequences for the child
Timely medical intervention can largely correct the severity of bleeding during placenta previa, but in approximately 20% of cases the child suffers in one way or another from the atypical location of the baby's place. This is indicated by the following factors:
- Congenital anemia
- Prolonged hypoxia
- Fetal anomalies
- Hypotrophy
Often, severe bleeding can lead to the death of the fetus, as well as the death of the mother herself, if emergency assistance is not provided on time.
To prevent placenta previa, treatment for STDs and chronic inflammatory diseases of the uterus can be recommended. At the planning stage, it is necessary to monitor the state of the endometrium and its physiological changes depending on the change in the first and second phases using ultrasound for at least two cycles.
