Why the fetus dies in early and late pregnancy: reasons, what to do

A frozen fetus is the cessation of all vital functions of the child in utero even before birth. This is a very serious pathology that is dangerous not only for the life of the baby, but also for the life of the mother. Therefore, it is very important to diagnose this condition in time and take preventive measures to prevent complications.

Epidemiology

Statistics on the prevalence of the pathology of fetal freezing are such that about 6% of women encounter this problem, and about 87% - during their first pregnancy. In 99% of cases, there is an obvious cause or a number of factors that cause this condition. About 80% of cases of monoamniotic twins with feto-fetal transfusion syndrome, one fetus dies and freezes in the early stages of pregnancy.

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Causes frozen fetus

Of course, the birth of a child is happiness for every woman. But in certain cases, the child may die in utero, which is called fetal fading. To prevent other cases of such a pregnancy, the mother needs to find out the reason that could lead to this.

The reasons for fetal fading can be divided into several groups.

1. Anomalies of egg cell placement and disorders of their chromosomal structure. This happens more often when a woman is over 35 years old. Then the probability of a mutation in the egg or directly in the cells of the embryo increases, since during this time many different factors have acted on the mother's body. This can lead to normal implantation of the egg, but at a certain stage of pregnancy development, a mutation occurs that does not allow the child to be born. A protective mechanism is triggered and the pregnancy can end.
2. Hormonal disorders in the mother before and during pregnancy. Deficiency of certain hormones that control not only implantation but also support the function of the placenta is one of the most common causes of fetal trophic disorders. Up to a certain point, such disorders can be compensated, but then an acute lack of placental function may occur, which will lead to the death of the fetus in utero.
3. The infectious process in the mother is acute or chronic. Any microorganism, be it a virus or bacteria, can penetrate the placenta and disrupt cell differentiation and the functioning of the fetus's organs. Certain bacteria and viruses have a certain effect, but any of these pathogens can cause an acute reaction in the fetus. Microorganisms from the TORCH group are considered the most dangerous for the child. Viruses are considered stronger inducers of mutations, so they are more likely to cause fetal death. Women are often found to be infected with the herpes virus. Can herpes cause fetal death? With herpes infection, the fetal membranes are affected, in particular the chorion. Necrosis of the chorionic villi occurs, leukocyte infiltrates, large histiocytes with disintegrating nuclei, and intranuclear inclusions appear. Dystrophic changes in the syncytium, stromal fibrosis, and changes in the vascular network of the villi with thickening of the walls are observed. These changes are clinically expressed in chronic placental insufficiency, which over time leads to a decrease in fetal nutrition and death due to a lack of oxygen and nutrients.
4. Pathology of the structure or function of female genital organs often allows pregnancy, but does not allow normal childbirth. Malformations of the uterus (saddle-shaped, double), violations of the histological structure of the uterus, ovarian insufficiency - all this leads to the fact that pregnancy can occur, but cannot develop normally. Also, inflammatory processes of the ovaries can be attributed to this group of reasons. Such a process can be asymptomatic, but when pregnancy occurs, the process is activated. Then the microorganism itself can become a mutagen in relation to the fetus, or insufficiency of the inflamed ovary occurs, which no longer allows the hormones necessary for pregnancy to be produced.
5. Immunological causes of the development of frozen pregnancy are the most common. During pregnancy, the immunological activity of the mother's body decreases so that the fetus is not perceived as a foreign organism and there are no immune reactions. In women who have autoimmune diseases or a deficiency of the immune response system, such a reaction occurs differently. The pathogenesis of frozen pregnancy is as follows: any factor that leads to the death of the fetus in utero should cause a reaction of rejection of the dead fetus. But when the immune reactivity fails, such a reaction does not occur, which leads to the fact that the dead fetus continues to be in utero for some time.
6. Gestational endotheliopathy is an endothelial lesion, which results in disturbances of physiological processes that ensure adequate uteroplacental-fetal blood supply. Conditions for the development of gestational endotheliopathy arise when trophoblast invasion into the spiral vessels of the uterus is disrupted, as a result of which they partially or completely retain the muscular layer and are able to respond to the effects of vascular-active substances by narrowing or expanding. Dysfunction of the endothelium manifests itself in excessive synthesis of vasoconstrictors, activation of blood clotting, which results in disruption of the nutrition of the embryo or fetus and its death in utero.
7. Antiphospholipid syndrome is a recently diagnosed pathology, which is accompanied by disorders of the coagulation system in the vessels with frequent thromboses. The pathology occurs due to the formation of specific antibodies against phospholipids of cells. Changes affect the fetus very often. Pathology of the placenta occurs, which is accompanied by infarctions and necrosis of the placenta, accumulation of fibrinoid masses in the intervillous space, atherosis and thrombosis of the spiral arteries. To this are added disorders of placental development - dystrophic changes in the syncytium, fibrosis of the stroma and changes in the vascular network of the villi with thickening of the walls. This causes a double risk of developing placental insufficiency and fetal death in the early stages.
8. Many medications can cause a frozen pregnancy, and their immediate use is not as important as the fact of their use at all. What pills cause a frozen pregnancy? This group includes contraceptives, as well as drugs that are considered early means of terminating pregnancy.
9. Unfortunately, fetal freezing is more common in multiple pregnancies. There are often cases when, in monochorionic monoamniotic twins, one fetus has frozen. Why does this happen? When two fetuses have one placenta, anastomoses can form between their circulatory systems. These anastomoses allow blood to be discharged from one circulatory system to another by pressure gradient. One child becomes a donor and gives its blood through these vessels on the placenta to the second child - the recipient. Such "stealing" eventually leads to acute oxygen and nutrient deficiency, and the fetus dies in utero, while the other continues to live. There is no immune reaction, since there is a living fetus, so the dead child freezes.

Given the many reasons for pregnancy fading, it is necessary to identify risk factors for this pathology that cannot directly cause fetal fading, but can affect it if there is a reason. Such factors include the adverse effects of radiation, medications, high growth and body weight of the mother, nutritional characteristics with malnutrition and very strict diets.

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Symptoms frozen fetus

The danger of fetal freezing is precisely because the course of this pathology can be completely asymptomatic up to a certain point. Symptoms of a frozen fetus are more pronounced when it has already formed at a later stage.

A frozen fetus in early pregnancy is rarely diagnosed, since it occurs with symptoms of a miscarriage. If the fetus freezes in the first few hours, the body may not react as with a miscarriage. Only after a few hours can a reaction of rejection of the fetus occur, which will already have symptoms. Then there is pain in the lower abdomen, discharge.

A frozen fetus in the second trimester has a richer clinical picture, since all the organs and systems of the child have already formed during this period. The mother begins to feel the fetus's movements, its activity, and sometimes its heartbeat for the first time. This begins at the 19th-20th week of pregnancy. Therefore, the first signs of a frozen fetus in the second trimester are a sudden cessation of movements and any activity of the fetus. The mother immediately feels the changes, since previously all movements were active. Such a symptom may be preceded by a history of trauma or the action of a pathogenic factor. Along with this, the body temperature may increase, which does not always happen.

When the fetus freezes at a late stage, the symptoms are most pronounced. All movements slow down sharply, the woman may feel a sharp deterioration in her condition, which progresses dynamically. When the fetus freezes without a miscarriage, all the breakdown products and vital activity of the dead fetus enter the mother's body. Therefore, nausea may appear, the body temperature will rise, and intoxication will increase. Bloody discharge from the uterus or, over time, nagging pain in the abdomen may appear. But pronounced clinical signs are rare, and apart from the cessation of fetal movements and the disappearance of subjective sensations of the pregnant woman, there are rarely any symptoms.

When a pregnant woman develops twins and one fetus stops pregnancy, then diagnosis in most cases is only possible with the help of additional methods.

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Complications and consequences

The consequences of fetal fading for a woman's life are usually not dangerous if diagnosed in a timely manner. A frozen fetus may remain in the uterus for several days without symptoms, but then the rejection process begins and symptoms appear. If this process lasts for a very long time, there may be secondary infection and sepsis in the mother, since there is a supporting source of infection. Remote consequences of fetal fading may develop already in subsequent pregnancies. Since there is a delay of the fetus and its tissues in the uterus for a long time, this can lead to a violation of the histological structure of the endometrium. In the future, such changes threaten to disrupt the process of egg implantation or miscarriages. In addition, the longer the frozen fetus is in the uterus, the greater the likelihood of the formation of antibodies and the occurrence of an antigen conflict in the future.

Complications may arise in women after the fetus has frozen with the onset of the next pregnancy. Since the hormonal background is sharply disrupted, this may affect the further function of the ovaries. Therefore, after such a pregnancy result, women should be carefully examined and treated, observing an interval of at least a year before the onset of the next pregnancy.

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Diagnostics frozen fetus

Diagnosis may be difficult due to the poor clinical picture of this disease. Therefore, it is important to take into account the anamnestic data, and in the presence of trauma or the action of any other pathological factor - to carefully examine the woman.

If any pathology is suspected in pregnant women, an examination is carried out in mirrors and a manual examination. When examining in mirrors in the case of a frozen fetus, there is no pathology - the external os is closed, the cervix is formed, of normal height, the tone is not changed. During a manual examination, it can be established that the size of the uterus may be slightly smaller than expected for a given gestational age. At the same time, in the second trimester, the fetal heartbeat cannot be determined and there are no fetal movements during balloting.

Additional research methods are of great importance in diagnosing a frozen fetus. Especially if there are twins, then the signs of the cessation of vital activity of one of the fetuses are very difficult to determine with a simple examination.

Instrumental diagnostics of a frozen fetus necessarily includes ultrasound diagnostics and cardiotocography. Cardiotocography normally allows determining the fetal heartbeat, movement activity, and uterine tone. If there is a frozen fetus, then the heartbeat cannot be determined, which is an absolute sign of a frozen pregnancy. It may be that bradycardia is determined first with its gradual progression, and then heart contractions are not determined at all.

Ultrasound diagnostics allows identifying the fetus's location, heartbeat, size, position and blood flow. If there is a frozen fetus, the size of the fetal egg will be smaller than it should be for this period of pregnancy. There will be no growth of the fetal egg in dynamics. If we are talking about twins, one fetus may be significantly larger with a large amount of amniotic fluid, and the other will have a decrease in weight.

Biochemical parameters are also determined for diagnostic purposes. In the early stages, this is a very informative parameter, when the heartbeat cannot yet be detected. The most informative parameter is the determination of chorionic gonadotropin. This hormone is synthesized by the placenta to maintain normal pregnancy. If the fetus freezes in the early stages, its level is significantly lower than the gestational age.

Diagnosis of a frozen pregnancy is not only about establishing a diagnosis, but also about establishing the reason why it happened. Therefore, it is also very important to examine the fetus for abnormalities that could cause freezing. A comprehensive sectional study of the organs and tissues of the fetus is carried out. Genetic analysis of a frozen fetus is carried out to study the genotype to exclude chromosomal mutations. Most often, freezing of pregnancy in the early stages occurs precisely because of a genetic mutation. Buccal epithelium is most often used for research. Cytogenetic analysis of the fetus after a frozen pregnancy allows you to determine the number of chromosomes and their size under a microscope. Then, karyotyping is mandatory. Karyotyping of the fetus in a frozen pregnancy consists of distributing the chromosomes into special paired groups, where each chromosome has its own number. This allows you to compare the set of chromosomes and exclude aberrations.

Histology of a frozen fetus is a study of tissues to detect structural abnormalities and anomalies in the structure of organs that may be incompatible with life. Histological examination of the fetal heart, lungs, and brain is often performed to rule out serious pathologies that may lead to such an outcome. It is often possible to histologically determine changes in the tissue structure, which subsequently requires analysis for the presence of pathogenic microorganisms. Herpes infection can cause characteristic changes in brain tissue (cysts), liver - such complex diagnostics with histological study allows us to establish the preliminary cause of the frozen fetus.

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Differential diagnosis

Differential diagnostics of a frozen fetus should be carefully carried out when there is a pregnancy with twins. It is very important to diagnose the death of one of the fetuses in time, since the waste products of the dead fetus can get to the healthy child through the common placenta. This threatens the development of neurological disorders in the living fetus later after birth. When the development of the feto-fetal transfusion syndrome occurs, one fetus has a strong decrease in amniotic fluid, so that the chorion is tightly attached to the fetus. This immediately leads to the freezing of this child. In the early stages of pregnancy, during an ultrasound examination, it is difficult to notice the second frozen fetus and a singleton pregnancy is often diagnosed. Therefore, it is important to carry out differential diagnostics with a large amount of amniotic fluid with a possible multiple pregnancy.

Treatment frozen fetus

Suspected fetal freezing at any stage of pregnancy requires immediate hospitalization of the woman and her treatment in a hospital setting. If a diagnosis of fetal freezing is established using additional diagnostic methods, then treatment is mandatory to evacuate the fetus from the uterine cavity and terminate the pregnancy. Can a frozen fetus come out on its own? It should be emphasized that the wait-and-see tactic cannot be followed, since if the fetus has frozen without any signs of miscarriage, then the probability that it will "come out" on its own is very small. And if the frozen fetus remains in the uterine cavity for a long time, then this significantly increases the risk of bleeding and thrombotic complications.

The removal of a frozen fetus is done by medication or surgery. The shorter the gestational period, the more often surgical intervention is used. Cleaning of a frozen fetus in the early stages is done as an operation. An abortion is performed under general anesthesia with the fetus and all fetal membranes removed from the uterus. If the fetus has been in the uterus for a long time, this increases the risk of bleeding, so it is necessary to have all the drugs for blood transfusion. After the fetus is removed, the uterine cavity is revised so as not to leave parts of the membranes. After a week, an ultrasound examination of the uterus is considered mandatory to exclude complications of the operation.

In the second trimester of pregnancy, a medical removal of a frozen fetus is performed. For this purpose, drugs are used that stimulate uterine contractions and the release of the ovum. This is considered a less invasive intervention. Prostaglandin drugs or oxytocin are used.

Parenteral administration of oxytocin solution is the most effective drug method for inducing expulsion of the fetus in case of a frozen pregnancy. Oxytocin is usually prescribed at a concentration of 10 U/l (0.01 U/ml) of isotonic electrolyte solution or 5% glucose solution, but its dose should be individualized. Infusion is started at a rate of 0.01 U/min and increased in arithmetic progression every 15 minutes, but not more than 0.15 U/min. A dose of more than 0.4 U/ml leads to kidney damage and can be used in very rare cases. When the intensity of uterine contractions reaches 40-60 (with internal monitoring) or their duration is 40-60 at intervals of 1-4 minutes, stop increasing the oxytocin dose. If uterine contractions weaken, continue administering oxytocin. The infusion is slowed down or stopped if the intensity of uterine contractions is greater than 60, lasting more than 60 seconds, and the intervals between them are less than two minutes.

An antibacterial drug is prescribed individually for prophylactic purposes.

Prevention

Prevention of pregnancy fading consists of timely diagnostics of inflammatory diseases of the female genital organs, identification of risk factors. To prevent pregnancy fading in women who have already had such a pathology, a thorough examination is necessary after the first episode. It is very important to conduct genetic counseling of parents before planning the next pregnancy. Elimination of stress, improved diet, elimination of environmental factors - all this is very important for the development of a normal pregnancy in the future.

A frozen fetus is a type of miscarriage in which the fetus remains in the uterus and does not exit spontaneously. It is very important to diagnose this pathology in time, because clinical manifestations may not be expressed. The longer the frozen fetus remains in the uterus, the greater the risk of fatal complications for the mother. Given the seriousness of this problem, it is necessary to prevent this condition by all means.

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Forecast

The prognosis for the next normal pregnancy is good if the pregnancy has frozen for the first time. With each miscarriage, the risk of a repeated unsuccessful pregnancy increases. The prognosis is favorable for younger women without concomitant pathologies.