Such a disaster, although rare, does happen. According to statistics, this happens to every fifteenth woman. Seeing the long-awaited two lines on the test, the woman feels joy, but is soon severely disappointed, because on an ultrasound the doctor discovers a fertilized sac without an embryo. The diagnosis in this case sounds like anembryonic pregnancy.
A non-developing pregnancy of the anembryonic type is a type of frozen pregnancy. This syndrome is also called empty sac syndrome. That is, pregnancy has occurred, the membranes have formed, but the embryo is missing. At the same time, all external signs of pregnancy remain - absence of menstruation, enlarged breasts, fatigue, and the level of hCG in anembryonics continues to rise.
The diagnosis is made based on ultrasound of the embryo. The study should be carried out no earlier than 6-7 weeks, since at earlier stages this study is not indicative, the embryo is not visualized, and the doctor simply may not see its presence or absence. An erroneous diagnosis in the early stages may be due to the fact that the fetus is located near the wall and is not visible, or the fetus has a short amniotic leg.
Sometimes diagnostic errors occur if the gestational age is inaccurately determined. That is, at the time of examination, the embryo may be so small that the sensors of the ultrasound machine will not be able to detect its presence. Be that as it may, when you hear such a diagnosis, do not panic - insist on conducting additional checks at some intervals.
If you have been diagnosed with anembryonic pregnancy, you need to undergo additional examination by another specialist at intervals of 5-7 days. And only after confirmation of the sad phenomenon, go for termination of pregnancy (in common parlance - cleansing).
Anembryonic pregnancy is eliminated by curettage of the uterine cavity (curettage) under general anesthesia. After the operation, a repeat examination of the uterine cavity is performed. Sometimes a doctor may prescribe special hormonal medications to improve a woman's health.
Causes of pregnancy without an embryo
To the question - why is there no embryo implantation? – Doctors cannot give an exact answer. The most likely reasons for the development of an egg without an embryo are considered to be genetic disorders, infectious diseases, and hormonal characteristics.
The cause of anembryonia can be:
- an acute viral or bacterial infection in the early stages of pregnancy, which either affects the embryo or leads to a significant increase in the woman’s temperature, due to which the development process of the embryo is subject to destructive effects;
- the influence of toxic substances or radiation at the stage of fetal formation;
- hormonal imbalance in the female body;
- bad habits: smoking, alcoholism, drug use.
You can learn more about the factors that influenced pregnancy by conducting histological studies during surgery 
materials. To avoid a recurrence of an anembryonic pregnancy, both partners need to be tested for infections, undergo karyotype studies (genetic studies), and submit material for a spermogram.
Sometimes such a pregnancy develops in completely healthy parents. In this case, the prognosis for future pregnancies is very positive, that is, with a high degree of probability, you will not face a second pregnancy without an embryo. You just need to give your body a little rest from the resulting stress (about six months), gain strength and try to get pregnant again.
The embryo and the membranes surrounding it are the main initial components of the amniotic egg. As the fetus develops, the space around it also increases - this is a normal process of embryo development. Next, you are invited to familiarize yourself with key information directly about the fertilized egg, as well as regarding the peculiarities of changes in its size during pregnancy and possible pathologies of formation.
As you know, fertilization occurs through the penetration of a male sperm into a female egg. After this, the active process of embryo development begins: first, the fertilized egg is divided into 2 parts, then into 4, then into 8, etc. As the number of cells increases, the embryo itself grows. Without stopping to develop, the embryo moves towards its destination, which is normally the cavity of the female uterus. It is the mentioned group of cells that represents the fertilized egg in question. 
Once the desired location is reached, the embryo is implanted into the wall of the uterus. On average, this process takes up to 7-10 days after the sperm penetrates the egg. Until reaching its destination, nutrition of the fertilized egg is provided directly by the egg, and after consolidation, by the uterine mucosa.
Over time, the functions of providing nutrition to the embryo are taken over by the placenta, which is formed from the outer layer of the fertilized egg. Directly on the mentioned outer layer there are so-called. villi, which ensure implantation of the embryo in a suitable place. 
The formation and successful consolidation of the fertilized egg is the main sign of the normal course of female pregnancy. On average, the embryo becomes visible during ultrasound examination 5 weeks after the missed period, while the fertilized egg can usually be seen after 2 weeks. If during the first ultrasound the doctor sees the so-called. empty ovum, after a couple of weeks the test is repeated. 
Normally, the embryo is visualized by the 6-7th week of pregnancy. During the same period, his heartbeat is usually noticeable. If there is no embryo in the ovum during repeated ultrasound examination, a non-developing pregnancy is diagnosed. 
In view of this, if menstruation is delayed, a woman should have an ultrasound scan as early as possible in order to promptly detect existing abnormalities and, if such a possibility is present, undergo treatment to eliminate the identified problems.
When assessing the condition of the ovum, the specialist first of all pays attention to its shape and internal diameter. During the first weeks, the shape of the fertilized egg is close to oval. By assessing the internal diameter, the doctor can draw conclusions about the expected gestational age. Along with this, not every woman’s fertilized egg has the same size, so when determining the gestational age, an error often occurs, averaging one and a half weeks. For more accurate results, fetal CTE and other diagnostic measures are assessed. 
Features of the growth of the fertilized egg
As noted, the size of the fertilized egg, in the absence of various kinds of pathologies, is constantly increasing.
More detailed weekly information regarding the normal size of the gestational sac is given in the following table. 
Table. Sizes of fertilized egg by week
Possible developmental disorders of the ovum
Under the influence of certain factors, the development of the fertilized egg can occur with certain pathologies. You can find a description of the most commonly diagnosed anomalies in the following table.
Table. Pathologies of development of the ovum
| Pathologies | Description |
|---|---|
| Form violations | The shape of the fertilized egg in both scans up to 5-6 weeks is usually round. By 6-7 weeks, the fetal egg becomes oval in a longitudinal scan, but remains round in a transverse scan. Along with this, the development of form can occur with various kinds of deviations. Most often, this is caused by various types of tumors in the uterine cavity. Also, this pathology can occur in the case of partial placental abruption. |
| Pathologies of location | In the absence of deviations, implantation of the fertilized egg most often occurs in the fundus of the uterus or its posterior wall, sometimes in the area of the internal os or at the top of the uterus. Other options for the location of the ovum are assessed by a specialist. He also makes a decision on further actions in relation to a particular patient. |
| Dimensional violations | Information regarding changes in the size of the ovum as pregnancy progresses has been provided previously. Significant deviations from the given values in both directions are considered pathological, and conclusions about their significance are made by a specialist. |
| Functional pathologies |
It is impossible to give any definite answer regarding the causes of the development and treatment of pathologies in the development of the ovum - each case requires individual consideration by a qualified specialist. Only a doctor can objectively assess the situation and make the most appropriate decision. 
Sometimes it happens that the long-awaited two lines on the test do not last long - the doctor diagnoses you with an empty sac. In other words, this phenomenon is called.
This means that pregnancy has occurred, but there is no embryo, its development does not occur. Only the fertilized egg and surrounding tissues grow, but sooner or later this will end in miscarriage. Typically, a miscarriage occurs no later than the end of the first trimester - that is, before the 12th week of pregnancy.
At the same time, the woman does not have any symptoms or signs of an empty ovum, because she feels everything that she does during a normal pregnancy: nausea, drowsiness, fatigue. Her period stops, her breasts swell, and the test shows pregnancy. Unfortunately, all this will not last long - even if you do not interfere with the process, the body will soon reject the empty shell.
The absence of an embryo in the fertilized egg is diagnosed by ultrasound. Moreover, it is impossible to see the embryo before 6-7 weeks due to its tiny size. But already at 7 weeks the doctor should detect it, as well as his heartbeat. If this is not the case, there is a high probability of anembryonic pregnancy.
If the diagnosis of an empty ovum is confirmed by several ultrasound scans from different specialists and with a difference of about a week, then there is no need to wait for the spontaneous resolution of the situation. This is very difficult both psychologically and physically not useful. Therefore, women with this problem undergo “cleansing” under general anesthesia.
After this, there is no need to rush into a new pregnancy. Allow your body to recover from such shock and intervention. You need to wait at least six months, then try again.
Empty fertilized egg - reasons
As for the reasons for this phenomenon, they have not been fully studied. It is likely that existing genetic disorders played a role here. 
spouses, hormonal imbalance, infectious disease.
To find out more precisely about the reasons, you need to undergo an examination: get tested for infections, conduct a study of the karyotype of both partners, for a man -. Histological examination of the material after curettage also helps to obtain an answer.
If the spouses do not have chromosomal diseases, there is every chance of a successful second pregnancy. There was probably an unexplained genetic failure, but it won't happen again. Therefore, feel free to plan your children, not forgetting to consult with a competent specialist.
Unfortunately, not all pregnancies result in childbearing. Reproductive losses can be due to various reasons. And one of them is a non-developing or frozen pregnancy. According to medical statistics, this pathology accounts for up to 15-20% of reproductive losses.
Currently, there are 2 options for frozen pregnancy: embryonic death and anembryony. It is important to understand that differential diagnosis between them does not affect subsequent treatment tactics, but is taken into account when assessing the prognosis. Anembryonia is more often determined, and this condition in many cases is not accompanied by spontaneous abortion and therefore requires artificial termination of a frozen pregnancy.
Anembryonia - what is it and why does it develop?
Anembryony is the absence of an embryo in the developing fertilized egg. This condition is also called empty sac syndrome. This is by no means a rare pathology that can be diagnosed in primigravidas and in women who already have healthy children.
Currently, many possible causes of anembryonia have been identified. These include:
- Genetic abnormalities that are observed in almost 80% of the pathological condition. They are usually associated with gross and/or multiple chromosomal abnormalities. Moreover, with anembryonia, such anomalies are qualitative in nature, and with the death of the embryo and its abortion, they are predominantly quantitative. Nonviable combinations of parental genes or mutations in key areas responsible for the early stages of embryogenesis and the synthesis of the main structural proteins of cell membranes are also possible.
- Some acute viral and bacterial diseases that occur in the early stages of gestation and lead to damage to embryonic tissues or trophoblast. The most dangerous in this regard, although other pathogens can exhibit embryotropism.
- Persistent viral-bacterial infections of the reproductive system, leading to the development. And in most cases, this pathology occurs without obvious clinical symptoms and is detected after a frozen pregnancy.
- Radiation effects on a developing embryo.
- Exogenous intoxications: taking drugs with embryotoxic effects, drug addiction, exposure to certain industrial and agricultural poisons (toxins).
- Endocrine disorders in a pregnant woman. And the most critical is progesterone deficiency and disturbances in its metabolism, which is the main cause of the pathology of endometrial decidualization and abnormal implantation of the fertilized egg.
In general, the causes of pathology in most cases remain undiagnosed. Usually it is possible to determine only the presumptive etiology.
Carrying out genetic diagnosis of aborted tissue can reveal obvious anomalies of hereditary material. But such research, unfortunately, is carried out in a very small percentage of cases. Basically, it is indicated for a woman with a burdened obstetric history, when she has already had a frozen or spontaneously interrupted pregnancy in the early stages of gestation. But even such diagnostics are not always sufficiently informative, which is due to the limited capabilities of modern genetics and the high probability of exposure to other etiological factors.
Pathogenesis
Anembryony is a consequence of the cessation of reproduction and differentiation of the embryoblast or inner cell mass - a group of cells that normally give rise to fetal tissues. And this happens in the very early stages of pregnancy (usually 2-4 weeks of gestation), and without disrupting the development of membranes from the trophoblast. As a result, a so-called empty fertilized egg is formed, which continues to grow even if there is no embryo in it.
Pathogenetically important factors in the development of the disease include:
- Inherited from parents or acquired chromosomal aberrations and other genetic abnormalities. They can lead to gross desynchronization of the development of embryonic tissues, critical changes in the structure of collagen and other proteins, and disruption of the induction of differentiation and migration of dividing cells. The most common are autosomal trisomy, monosomy, triploidy, and tetraploidy.
- Excessive formation of circulating immune complexes in a woman’s body. Their deposition in the walls of small vessels leads to thromboembolism and other critical microcirculation disorders in the area of the implanting egg. Antiphospholipid antibodies are of greatest clinical importance.
- Excessive activation of T-helper cells with an increase in the concentration and aggression of the cytokines they secrete. These substances can have a direct and indirect damaging effect on embryonic tissues, disrupting their proliferation and differentiation. In fact, the fertilized egg in this case acts as a target for the cellular component of immunity. The cause of such an abnormal immune response of a woman’s body may be a chronic infection of the endometrium, hormonal abnormalities, and some other endogenous factors.
It is important to understand that with anembryonia, a woman’s body produces substances that help prolong pregnancy. Therefore, in a significant proportion of cases, spontaneous abortion does not occur. The patient develops and maintains signs of pregnancy, and an increase in hCG in the blood serum occurs. Therefore, the basal temperature during anembryonia usually does not have any characteristic features. And it confirms the fact of successful implantation of the fertilized egg in the uterine cavity. After all, pregnancy does occur, but it develops without a key component - the embryo.
Subsequently, rejection of the abnormal fertilized egg is possible. In this case, a threatened miscarriage (including the formation of exfoliating retrochorial hematomas) or spontaneous abortion (miscarriage) can be diagnosed. But often anembryonia is diagnosed only during a routine examination, in which case the diagnosis is completely unexpected and shocking news. Such a pregnancy requires artificial termination.
How does this manifest itself?
Anembryonia does not have its own clinical symptoms; all emerging disorders are usually associated with the threat of termination of such a pathological pregnancy. Warning signs include the presence of clinical manifestations of relative progesterone deficiency, which creates the preconditions for spontaneous abortion. Therefore, the reason to consult a doctor may be pain in the lower abdomen and spotting; with anembryonia, they can appear at almost any time during the 1st trimester.
But often a woman learns about the existing pathology only during a screening ultrasound at 10-14 weeks.
Diagnostics
Like other forms of frozen pregnancy, anembryonia is detected in the first trimester of gestation. And the main diagnostic tool is, because it is this study that allows you to visualize existing deviations.
At the same time, symptoms can be reliably identified only after the 8th week of gestation. At earlier stages, visualization is often insufficient due to the too small size of the gestational sac, so an erroneous diagnosis cannot be ruled out. Therefore, if you suspect a frozen pregnancy or anembryonia, it is recommended to carry out the examination several times, repeating the procedure using expert-class equipment with an interval of 6-8 days. In this case, the initial diagnosis of an empty sac can be removed if subsequent ultrasounds can visualize an embryo with signs of a heartbeat and sufficient developmental dynamics.
Main echographic signs:
- absence of a yolk sac when the diameter of the fertilized egg is 8-25 mm;
- absence of an embryo in a fertilized egg with a diameter of more than 25 mm.
Additional signs include irregular shape of the fertilized egg, insufficient increase in its diameter over time, weak severity of the decidual reaction, absence of heartbeat at a gestation period of 7 or more weeks. And signs of the threat of its interruption are changes in the tone of the uterus and the appearance of areas of chorionic detachment with the appearance of subchorionic hematomas.
Anembryonia can also be suspected by dynamically assessing the level of hCG in the blood. An increase in the level of this hormone at the lower limit of normal should be the basis for further examination of the woman with an ultrasound. It is important to understand that hCG is also produced during empty ovum syndrome. Moreover, its level in this pathology will be almost normal, in contrast to a frozen pregnancy with the death of a normally developing embryo. Therefore, monitoring indirect signs of pregnancy and the increase in hCG during anembryonia cannot be considered reliable diagnostic methods.
Varieties
There are several possible variants of empty sac syndrome:
- Anembryonia type I. The embryo and its remains are not visualized; the size of the fertilized egg and uterus does not correspond to the expected gestational age. The diameter of the egg is usually no more than 2.5 mm, and the uterus is enlarged only until 5-7 weeks of gestation.
- Anembryonia type II. There is no embryo, but the fertilized egg and uterus correspond to the gestational age.
- Resorption of one or more embryos during. In this case, normally developing and regressing fertilized eggs are simultaneously visualized. This type of anembryonia often occurs after IVF if several embryos were implanted into a woman.
All these varieties are determined only with the help of ultrasound; they do not have characteristic clinical features.
What to do?
Confirmed anembryonia is an indication for artificial termination of pregnancy. This does not take into account the gestational age, the woman’s well-being and whether she has signs of a possible spontaneous abortion. An exception is the situation when anembryony of the second ovum is diagnosed during a multiple pregnancy. In this case, a wait-and-see approach is taken, assessing the dynamics of the development of the surviving embryo.
Termination of a frozen pregnancy is carried out only in a hospital. After the procedure for evacuation of the fertilized egg, the woman should be under medical supervision. In many cases, she is then prescribed additional medication and sometimes physiotherapeutic treatment aimed at normalizing hormonal levels, preventing inflammatory and hemorrhagic complications, and eliminating the identified infection.
To perform a medical abortion for this pathology, it is possible to use several methods; the choice depends on the technical equipment of the medical institution and the gestational age. Can be used:
- medical abortion - termination of pregnancy using hormonal drugs that provoke rejection of the endometrium along with the implanted fertilized egg;
- vacuum aspiration of the contents of the uterine cavity;
- curettage is an operation that includes mechanical removal of the fertilized egg and endometrium with a special instrument (curette) after forced dilation of the cervical canal with bougies.
Medical abortion for anembryonics is possible only at 6-8 weeks. In later stages of gestation, preference is given to mechanical methods, which require the use of general anesthesia. The choice of method of artificial abortion determines whether the stomach hurts after termination of pregnancy, the duration of the rehabilitation period, and the likelihood of developing early and late complications.
The examination after an induced abortion necessarily includes ultrasound control. This makes it possible to confirm the complete evacuation of the membranes and endometrium, to exclude undesirable consequences of abortion in the form of perforation, etc.
Forecast
Can anembryony happen again? Will I be able to have children again? These questions worry all patients who have suffered this pathology. Fortunately, in most cases the condition does not recur; the woman subsequently manages to become pregnant safely and carry a child to term. But at the same time, she is considered to be at risk for the possible development of complications of pregnancy and childbirth. Therefore, in the first trimester, she is usually prescribed dynamic ultrasound monitoring of the development of the fetal egg, determination of the hormonal profile and assessment of the state of the hemostatic system.
Pregnancy after anembryony is theoretically possible already in the next ovarian-menstrual cycle. But it is advisable to let the body recover. Therefore, it is recommended to begin planning for reconception no earlier than 3 months after an induced abortion. If it proceeded with complications, the rehabilitation period, subject to reproductive rest, is extended for up to six months. If a woman is diagnosed with chronic endometritis and various infections, a control examination is carried out 2 months after completion of treatment and only then the possible timing of reconception is determined.
To prevent pregnancy, preference is given to the barrier method and hormonal contraception. The selection of funds is carried out individually. Intrauterine devices are not used immediately after a frozen pregnancy to avoid the development of endometritis.
Prevention
Primary prevention of anembryonia includes careful planning of pregnancy with a comprehensive examination. If deviations are detected, they are corrected. Of course, such preparation does not eliminate the possibility of pathology 100%, but it reduces the risk of its development.
Secondary prevention is carried out if a woman has a history of spontaneous abortions and anembryonia. The first pregnancy with empty ovum syndrome is a reason for subsequent examination of the woman for infections and hemostasis disorders. If the situation repeats, a genetic examination of the spouses is also indicated to exclude anomalies of hereditary material. In some cases, subsequent conception is preferably carried out using IVF, which will allow the use of preimplantation diagnostics to detect chromosomal abnormalities in embryos.
Anembryonia is diagnosed quite often. And, unfortunately, at present it is not yet possible to completely exclude such pathology at the stage of pregnancy planning. After all, it can develop even in completely healthy and examined patients. At the same time, suffering a frozen pregnancy does not mean the impossibility of a successful conception again; most women after anembryonia manage to safely give birth to a healthy child.
The diagnosis of an empty fertilized sac without an embryo is not uncommon; it is made in 5-10% of cases. The most unpleasant thing is that the chances of identifying its causes are minimal. For a planned pregnancy to be successful, experts recommend taking multivitamin complexes and leading a healthy lifestyle.
This is what an empty fertilized egg looks like on an ultrasound.
An empty fertilized egg is essentially a pregnancy that has not begun to develop. The development process stopped even before the stage of embryo formation. There are many reasons for this violation. Any negative changes in a woman’s body can provoke it. When diagnosing anembryonia, the necessary measures should be taken immediately, as this entails the inevitable death of the fetus.
Among the main reasons for an empty ovum are:
- Genetic disorders.
- Infectious diseases.
- External factors (state of the environment).
- Wrong diet.
- Lack of vitamins.
That is, in each specific situation, it is extremely difficult to determine the reason for the formation of an empty fertilized egg. Genetic disorders begin at the initial stage of cell division and entail subsequent errors. This may be the formation of extra chromosomes or, conversely, an incomplete set of them. In this case, the egg does not transform into an embryo; the woman’s body understands this and begins to reject it.
According to statistics, out of 100 women, 5-10 do not have an embryo in the ovum.
How does anembryonia manifest?
At the initial stage, an empty pregnancy will not be noticeable. It cannot be determined even with the help of a gynecological examination. Violations become visible already at the most extreme stage, when the body begins to reject the fetus. At this stage, there is pain in the lower abdomen, brown vaginal discharge and a pungent odor - and these are already signs of a fertilized egg without an embryo that the body has begun to reject.
How does hCG change when the ovum is empty?
Monitoring the dynamics of hCG is one of the ways to determine an empty ovum. HCG values will change, but significantly less than during normal pregnancy. It is also possible that the hCG values stay the same - this is the main sign of the existence of problems with fetal development.
Be sure to watch this useful video:
The symptoms of an empty pregnancy are no different from a normal one: a delay in menstruation, manifestations of toxicosis, and a constant feeling of fatigue.
In the early stages, it is extremely difficult to identify an empty fertilized egg. Since the size of the embryo is very small and it can simply not be noticed. Only after 5 weeks does it become possible to determine the absence of a fetus.
Ultrasound diagnostics
Only in the sixth week of pregnancy can an empty ovum be diagnosed using ultrasound. It is carried out in any case to determine the location of the fetus, as well as to exclude ectopic pregnancy. A woman can hear such a terrible diagnosis as anembryonia even if she feels well and has no symptoms. The first trimester of pregnancy is the most important time for the formation of the fetus; at this stage, the expectant mother should especially carefully monitor her health, since the threat of miscarriage is very high.
This video shows an ultrasound of an empty ovum:
If a woman is found to have an empty fertilized egg without an embryo, she will need to undergo medical correction (cleansing the uterus).
What to do with anembryonia?
If such a disappointing diagnosis was made, it will be necessary to make a correction. Medical correction is possible using two methods.
Surgical method
This is the most common correction option. This method allows you to clean the uterine cavity without consequences. During surgery, general anesthesia is used. The operation takes place very quickly, from 10 to 25 minutes. The doctor must scrape out the uterine layer and the empty fertilized egg. After just a couple of hours, the woman can go home.
Medical abortion
Abortion using special drugs can be used if the pregnancy is less than 6 weeks. The woman takes the medicine and waits for contractions to begin. It hurts. The entire procedure takes place in a hospital under the supervision of a doctor. After all the excess has come out of the uterus, the woman must spend a couple of days in the hospital until the bleeding stops.
To clarify the cause of the disruption of pregnancy, the material obtained from the uterus during the cleaning process is sent for histological examination. Such a study should find out the reasons for the cessation of embryo development and when exactly it stopped its development.
After an abortion you need to do an ultrasound.
When completing either of the two methods of abortion, an ultrasound scan must be performed. In this way, you can make sure that the uterus is clean and there are no particles of the fertilized egg left in it.
Prevention
It is better to prevent a problem than to solve its consequences. If an empty fertilized egg is detected, then extreme measures are taken. But if you follow some recommendations when planning a pregnancy, you can reduce the likelihood of developing pathologies.
You can reduce the risk of an empty sac forming in the following ways:
- both spouses undergo a full medical examination (do tests, ultrasound, consult with a gynecologist and therapist to rule out chronic diseases, it is also recommended to visit specialists);
- on the recommendation of a specialist, start taking multivitamins, including folic acid. A course of vitamins should be started 2-3 months before conception;
- When preparing for pregnancy, you should give up bad habits: drinking alcohol, smoking. Review your diet and diet: fill it with foods rich in vitamins and minerals.
Brief summary
It is worth agreeing in advance with an obstetrician-gynecologist who will advise you throughout your pregnancy. It is important to understand that an isolated case of an empty ovum is not a death sentence. This absolutely does not mean that one of the partners has disorders in the reproductive system. The main thing is not to get upset and continue trying to get pregnant ( after anembryony, procreation can be started within six months), then everything will definitely work out.