What is placenta previa and how does it affect pregnancy and childbirth?

Placenta previa, a condition in which the placenta is positioned abnormally low in the uterus, is one issue that may come up during pregnancy. The placenta covers or lies very close to the cervix rather than adhering to the upper portion of the uterine wall. As the pregnancy goes on, this could cause issues.

Because placenta previa can affect both the mother’s and the child’s health, it is crucial to understand it. The placenta may partially or totally obstruct the birth canal as the pregnancy progresses and the baby grows. In order to protect the mother and child, this may cause bleeding and call for additional care.

We’ll discuss placenta previa’s definition, diagnosis process, and potential effects on the course of pregnancy and delivery in this article. We’ll also talk about the actions that can be taken to control the illness and guarantee the mother’s and the child’s health.

Definition

Ancient doctors called the placenta "baby"s place". Even from Latin, the word "placenta" is translated as "baby"s place", "afterbirth", "cake". All these comparisons quite clearly describe the placental tissue. The placenta is formed only during pregnancy. Through it, the baby receives all the nutrients necessary for its growth and intrauterine development, as well as oxygen. Numerous blood vessels pass through the "children"s place", which provide uninterrupted blood flow between the mother and the child. This unique circulatory system, which occurs only during pregnancy, is called the uteroplacental blood flow system. The embryonic membranes of the chorion participate in the formation of the placenta. They form dense villous growths that tightly penetrate the wall of the uterus. Such attachment ensures the fixation of the placental tissue. During childbirth, it separates after the birth of the child and is called the "afterbirth". Normally, the placental tissue is formed slightly higher than the internal os of the uterus. In the 2nd trimester of pregnancy, the placenta should normally be 5 cm higher than the os. If for some reason the placental tissue is located lower, then this is already a sign of a placental defect – low attachment of the placenta.

The placental tissue typically lies about 7 cm away from the internal os during the third trimester of pregnancy. It’s easy to figure out where the placenta is. Exams using ultrasound technology are used for this. These straightforward diagnostic techniques enable medical professionals to pinpoint the exact height of the placental tissue with high accuracy.

This clinical condition is referred to as presentation if the placenta is situated in the lower regions of the uterus and even touches the internal os. The placental tissue may "go" partially or entirely onto the os in such a scenario. Based on statistical data, this condition affects between 1% and 3% of pregnancies.

Normal location

The placenta typically develops on the uterine wall’s back wall. Additionally, it has the ability to move to the left and right side walls. The back wall and the fundus of the uterus have a fairly good blood supply. The fetus cannot fully develop intrauterine if blood supply vessels are not present. The placenta’s proper position ensures that the developing baby grows physiologically inside the mother’s womb.

Rarely does placental tissue attach itself to the uterine anterior wall. The problem is that a lot of different influences can have an impact on this area. The placenta’s relatively soft tissue can be damaged by mechanical harm and injuries, which is a very dangerous situation.

Because there is no longer any blood supply to the fetus following a placental rupture, there is a risk of acute oxygen deficiency developing.

There’s no need to panic if the pathology of the placenta’s normal position was discovered between 18 and 20 weeks. There is still a good chance that the placental tissue will move before labor begins. Numerous different factors have an impact on this. A better prognosis may result from early detection of placenta previa, which enables medical professionals to closely monitor the pregnancy’s progress.

Causes of occurrence

The location of the placental fabric’s attachment can vary due to several factors. The placenta’s actual location is decided upon post-fertilization. The fertilized egg should normally attach to the fundus of the uterus.

In this case, the placental tissue will also attach correctly. If for some reason the embryo implants not in the fundus of the uterus, then the placenta will also be nearby. The most common and frequently encountered cause leading to the development of placenta previa is the consequences of various gynecological diseases accompanied by inflammation of the inner wall of the uterus (endometrium). The chronic inflammatory process damages the delicate mucous membrane of the uterus, which can also affect the attachment of the placental tissue. In this case, the fertilized egg simply cannot fully attach (implant) into the wall of the uterus in the area of ​​its fundus and begins to descend below. As a rule, it shifts to the lower parts of the uterus, where it is attached. Also, the development of placenta previa can be facilitated by various gynecological surgeries performed before pregnancy. These can be curettage, cesarean section, myomectomy and many others. The risk of developing placenta previa in this case is much higher in the first year after the surgical treatment.

The likelihood of placenta previa in a subsequent pregnancy decreases with the amount of time that has elapsed since the gynecological surgeries.

• the presence of a complicated obstetric and gynecological history (previous abortions, surgical curettage, previous difficult births and much more);
• chronic gynecological diseases (endometriosis, salpingitis, vaginitis, myoma, endometritis, cervical diseases and others);
• hormonal pathologies associated with ovarian pathology and accompanied by irregularities in the menstrual cycle;
• congenital anomalies in the structure of female genital organs (underdevelopment or prolapse of the uterus, ovarian hypoplasia, etc.).

If a woman is in a high-risk category, her pregnancy is closely monitored by medical professionals. The quantity of vaginal exams conducted is reduced in such circumstances. Additionally, transabdominal ultrasonography is preferred over transvaginal ultrasound for diagnostic purposes. Individualized recommendations are given to expectant mothers early in pregnancy with the goal of reducing the risk of adverse symptoms of placenta previa pathology.

Clinical options

Experts pinpoint a number of potential clinical scenarios where placental tissue may be found in relation to the uterus’ internal organs. Among them are:

• complete presentation;
• partial (incomplete) presentation.

The inner pharynx is nearly entirely covered by the placental fabric when it is fully presented. Statistics show that in 20–30% of cases of placenta previa, this condition arises.

If the placenta only partially moves to the internal os, obstetricians and gynecologists refer to this condition as partial placenta previa. This pathology already occurs in about 70–80% of all cases of placenta previa pregnancies, which makes it somewhat more common.

Classification

Ultrasonography can be used to measure the degree of internal os placental tissue overlap. Physicians employ a unique categorization that offers a range of clinical alternatives. Considering the evaluated symptoms, this pathology may be:

• 1 degree. In this case, the placental tissue is quite close to the opening of the cervix. Its edges are higher than the internal os, by 3 cm.
• 2 degrees. In this case, the lower edge of the placenta is practically at the entrance to the cervical canal, without overlapping it.
• 3 degrees. The lower edges of the placenta begin to block the internal uterine pharynx almost completely. In this situation, the placental tissue is usually located on the anterior or posterior uterine wall.
• 4 degrees. In this case, the placental tissue completely blocks the entrance to the cervical canal. The entire central part of the placenta "enters" the area of ​​​​the internal uterine os. In this case, there are separate areas of placental tissue on both the anterior and posterior walls of the uterus.

Obstetricians and gynecologists use old, tried-and-true techniques in addition to ultrasound examinations to diagnose different options regarding placenta location. Among them is the vaginal exam. A skilled and knowledgeable physician can locate the "baby’s place" with speed and accuracy. The following localizations are possible for it:

• In the center. This type of presentation is called central placenta previa – placenta praevia centralis.
• On the sides. This version of presentation is called lateral or placenta praevia lateralis.
• At the edges. This variant is also called marginal or placenta praevia marginalis.

There are several similarities between the clinical classification and ultrasound. For instance, an ultrasound indicates that a central presentation corresponds to 3 or 4 degrees. Experts refer to it as complete as well. According to ultrasound, lateral presentation typically corresponds to 2 or 3 degrees.

According to ultrasound, the placental tissue’s marginal presentation is typically equal to 1-2 degrees. Another name for this clinical variation is partial.

Certain physicians employ an extra clinical classification. The location at which placental tissue attaches to the uterine walls is used to categorize presentations. Thus, it could be:

• Anterior. In this situation, the placental tissue is attached to the anterior uterine wall.
• Posterior. The placenta is mostly attached to the posterior wall of the uterus.

It is generally possible to identify the precise wall to which the placental fabric is attached as late as 25–27 weeks of pregnancy. But it’s crucial to keep in mind that the placenta’s position can shift, particularly if it’s attached to the uterine anterior wall.

Symptoms

It should be mentioned that the development of negative clinical signs is not always a sign of placenta previa. The degree of symptoms in partial placenta previa may be negligible.

The pregnant woman starts to exhibit adverse symptoms of this pathology if the placental tissue covers the internal os of the uterus to a significant extent. Bleeding is one of the potential symptoms that are indicative of placenta previa. It usually appears during the second trimester of pregnancy. On the other hand, some women experience vaginal bleeding considerably earlier, during the first few weeks of pregnancy.

There may be an increase in the severity of bleeding during the third trimester of pregnancy. This is mostly made possible by the uterus’s severe reduction and the fetus’s descent through the floor. The likelihood of experiencing severe bleeding increases with the proximity of the impending delivery.

Physicians surmise that the primary cause of the blood in the genital tract in this instance is the placenta’s incapacity to expand after the uterine walls have stretched. There is an increasing likelihood that the placenta will start to peel off, resulting in bleeding, as labor approaches.

It’s critical to realize that in this instance, the fetus does not lose its own blood. Under these circumstances, only the placental tissue itself ruptures. The risk associated with this condition is that the infant "living" in the mother’s womb could develop acute hypoxia, or oxygen starvation.

Generally speaking, certain effects make bleeding with placental tissue previa appear more easily. Thus, it may emerge following:

• lifting heavy objects;
• physical exertion and running;
• severe cough;
• careless vaginal examination or transvaginal ultrasound;
• sex;
• thermal procedures (baths, saunas, baths).

Blood from the genital tract may appear suddenly with complete presentation. It is typically a vivid, bright red color. The presence of pain symptoms is not guaranteed. Depending on the pregnant woman’s particular circumstances. The bleeding usually stops after a while.

When left untreated, bleeding from a pregnant woman’s genital tract typically occurs in the third trimester of the pregnancy and sometimes even at the first signs of labor. In this instance, the bleeding can range greatly in intensity from minimal to severe. Everything hinges on how much of the internal cervical os is covered by the placenta.

Migration of the placenta

The placenta may shift positions during pregnancy. We refer to this procedure as migration. It is mostly caused by physiological changes that occur in the lower uterine segments at various stages of pregnancy.

Generally speaking, placental migration along the anterior wall has the best prognosis. The placental tissue in this instance shifts slightly from its initial position. The placenta typically migrates very slowly or with difficulty if it is attached to the posterior wall. In actuality, there are instances where the placental tissue that is attached to the uterine posterior wall remains stationary during pregnancy.

The process of placental migration is typically slow. Ideally, if it happens in the next six to ten weeks. The expectant mother in this instance does not have any negative symptoms. By 33–34 weeks of gestation, the placental migration process usually comes to an end.

It can be dangerous if the placental tissue shifts positions too quickly—in less than one to two weeks—because the expectant mother may experience specific symptoms. As a result, a pregnant woman may experience pain in her abdomen or see vaginal bleeding.

He should not be reluctant to seek medical attention in this situation.

What complications can be?

Frequent bleeding is a bad indicator if it starts. A pregnant woman who experiences frequent blood losses runs the risk of becoming anemic and having her blood’s iron and hemoglobin levels drop. Anemia in the mother poses a risk to the developing foetus. The baby’s intrauterine development may be less intense due to a decrease in hemoglobin in placental blood flow, which will have a detrimental effect on his long-term health.

The formation of impromptu, unplanned genera could be another presentational issue. In this instance, the fetus might arrive much sooner. The infant may be premature and unable to lead an independent life in such a circumstance. There is also a chance of spontaneous miscarriage if placenta previa is excessively noticeable and progresses in an unfavorable manner.

Additionally, physicians observe that women who have placenta previa during pregnancy frequently struggle to keep their blood pressure levels within normal ranges. Hypotension is a condition where a woman’s blood pressure falls below the average for her age. Statistics show that in 20–30% of pregnancies with placenta previa, this pathology develops.

Gestational diabetes is one of the most serious side effects of pregnancy. Pregnant women who have placenta previa are not immune to this pathology. In this instance, late gestosis develops particularly frequently. Disorders in the functioning of internal organs and the emergence of blood clotting pathology accompany it.

Another condition that can arise from placenta previa is fetal-placental insufficiency. For the fetus, this condition is extremely dangerous. It is typified by a reduction in the oxygen flow to the child’s body, which has an adverse effect on the growth of the child’s heart and brain.

Experts have discovered that a fetus with placenta previa frequently has the uterus in the wrong position. The baby should be positioned head down for optimal physiological development.

Nonetheless, placenta previa may give rise to additional clinical variations. The fetus could be transverse, breech, or oblique, for instance. Pregnancy-related pathologies can develop when there are variations in the child’s position within the uterus. Additionally, these presentations might turn into a sign that surgical obstetric support is necessary. In these circumstances, expectant mothers frequently have a cesarean section.

How is the diagnosis made?

Without using an ultrasound, placental tissue previa can be suspected. Repeated bleeding from the genital tract in a pregnant woman may be a sign of this pathology, which typically manifests in the second or third trimester of pregnancy.

It is crucial to perform a clinical vaginal examination if blood is seen coming from the genital tract. In addition, any other diseases that might result in the emergence of comparable symptoms are ruled out. Additionally, the overall health of the fetus must be assessed due to this pathology. To do this, an ultrasound examination is carried out.

These days, an ultrasound is the primary diagnostic tool for placental cloth presentation. A skilled physician can quickly ascertain how much of the internal pharynx overlaps with the placenta. An ultrasonography specialist presents his future mother with a conclusion he compiled after finishing the study. A pregnant woman’s medical card must be invested in since it is essential to gather the right pregnancy strategies and monitor her in real time.

It is not desirable to perform repeated vaginal exams in the future if placental tissue is found in the vicinity of the internal os during an ultrasound examination. Doctors still use this examination when necessary, but they make every effort to do so with care and gentleness.

In this scenario, if placenta previa was detected early enough, the expectant mother will be advised to have multiple ultrasounds. Usually, they are done in the following order: at 16, 25, 26, and 34–36 weeks of pregnancy.

It is advised by experts to do an ultrasound examination while the bladder is full. In this scenario, the ultrasonographer’s ability to detect pathologies is greatly enhanced.

In the event of a hematoma, it is also possible to ascertain the amount of blood accumulation through an ultrasound examination. Its quantity is also inevitably evaluated in this instance. Therefore, if it represents less than ¼ of the placenta’s total area, the prognosis for this clinical condition is fairly favorable for the remainder of the pregnancy. In situations where the hemorrhage accounts for more than one-third of the placental tissue, the fetus’s chances of survival are not good.

Placenta previa is a condition that can cause problems during pregnancy when the placenta covers the cervix entirely or partially. It may need special treatment, such as bed rest or an early cesarean section delivery, and it can cause bleeding, particularly later in pregnancy. In order to manage the condition and guarantee the safety of mother and child during pregnancy and childbirth, early detection and monitoring are essential.

What measures should be taken?

It is critical that a pregnant woman contact her obstetrician-gynecologist right away if she experiences vaginal bleeding. A physician is the only one who can properly evaluate the condition’s severity and create a plan for the pregnancy’s ongoing care.

The expectant mother may also be placed under dispensary observation if placenta previa is not accompanied by the onset of adverse symptoms. If a pregnant woman’s pregnancy is going well, she won’t be admitted to a hospital. The expectant mother is compelled to receive advice at the same time, advising her to closely monitor her health. She is also advised to avoid lifting weights and to limit her intense physical activity. A placenta previa expectant mother needs to keep a close eye on her emotional state as well.

Severe uteroplacental vessel spasm can be brought on by nervous shocks and extreme stress. The resulting disruptions in blood flow can pose a serious risk to the fetus’s intrauterine development.

Treatment

Placenta previa therapy is typically administered in a hospital after 24–25 weeks. Here, physicians work to completely remove the possibility of an early birth. It is considerably simpler to keep an eye on the expectant mother’s and child’s overall health in a hospital.

The following guidelines must be followed when providing therapy:

• mandatory bed rest;
• prescription of drugs that normalize the tone of the uterus;
• prevention and treatment of anemic conditions and possible fetal-placental insufficiency.

A cesarean section may be necessary if the bleeding is excessive and does not stop and there is severe anemia. When a mother or fetus is in critical condition, surgery for vital indications can be carried out.

When placenta previa is fully developed, a cesarean section is done. Giving birth naturally can be extremely risky. The uterus contracts hard when labor starts, which increases the risk of placental abruption happening quickly. The intensity of uterine bleeding can be extremely strong in such circumstances. Surgical obstetrics is the method that doctors use to prevent severe blood loss and ensure a safe delivery of the baby.

The following situations may warrant a planned cesarean section:

• if the baby is in the wrong position;
• if there are extended scars on the uterus;
• with multiple pregnancies;
• with severe polyhydramnios;
• with a narrow pelvis in a pregnant woman;
• if the expectant mother is over 30 years old.

In certain situations, physicians might decide against using surgical obstetrics due to incomplete presentation. In this situation, they typically wait for labor to start, at which point the amniotic sac opens. In this case, opening is required to allow the fetal head to start moving along the birth canal in the proper direction.

In situations where the fetus experiences acute hypoxia or there is severe bleeding during a natural birth, a cesarean section is typically performed and the approach is modified accordingly. It is crucial to maintain control over the fetus’s and the laboring woman’s conditions. To do this, physicians simultaneously monitor multiple clinical indicators. In addition to many other indicators, they assess the uterine contractile activity, the neck opening, the mother’s and the fetus’s pulse and blood pressure.

The number of cesarean sections performed in medicine is rising. Based on statistical data, obstetricians and gynecologists tend to favor this approach to obstetric care in approximately 70–80% of pregnancies in which the placenta is visible.

Numerous diseases can develop during the postpartum period and complicate things for the placenta. A woman’s chances of having a difficult postpartum recovery increase with the difficulty of the pregnancy and the frequency of the bleeding. She might experience a decline in uterine tone in addition to gynecological disorders. Additionally, heavy bleeding from the uterus may occur during the postpartum phase.

After giving birth, you should keep a close eye on the general health and well-being of the mother who carried a baby with placenta previa. A woman should see her gynecologist right away if she feels extremely weak, dizzy all the time, and has bloody discharge for several months after the birth of the child. In cases like this, it’s important to rule out any potential surgical complications in addition to the emergence of a serious anemia.

Placenta Previa	Effect on Pregnancy and Childbirth
A condition where the placenta covers the cervix either partially or fully.	Increases the risk of bleeding during pregnancy and can complicate childbirth, often requiring a C-section.
Types	Partial or complete, depending on how much of the cervix is covered.
Symptoms	May cause painless bleeding, especially in the later stages of pregnancy.
Treatment	Monitoring, bed rest, and in some cases early delivery via C-section.

A condition known as placenta previa occurs when the placenta covers the cervix or is extremely close to it. Pregnancy and childbirth complications may result from this. To guarantee the best results for themselves and their child, expectant mothers should be aware of this condition.

An ultrasound is typically used to diagnose placenta previa. Physicians can monitor the condition and offer management advice if it is discovered early. As the pregnancy goes on, the placenta may occasionally separate from the cervix, lowering the possibility of problems.

The delivery options for women who have placenta previa may be impacted. To prevent complications during vaginal delivery, a cesarean section may be advised, depending on the severity and stage of the pregnancy. Keeping an eye on things and heeding doctor’s advice are essential to safely managing the condition.

Placenta previa can be worrisome overall, but the risks can be mitigated with appropriate prenatal care and monitoring. Positive outcomes for mother and child can be achieved by maintaining open communication with healthcare providers and following their advice.

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