Why does one embryo produce twins or triplets?

There is no embryo in the fertilized egg, 6 weeks have passed. What to do?

Unfortunately, not all visits to ultrasound during pregnancy end happily; sometimes doctors see that the embryo is not visible in the fertilized egg.
Anembryony is a type of undeveloped pregnancy in which a small embryo is formed, or more precisely, the absence of an embryo in the fertilized egg. To make such a diagnosis, it is necessary to undergo an ultrasound examination in the sixth week of pregnancy.

What does it mean if the embryo is not visible in the fertilized egg? People often ask on forums: “There is no embryo in the fertilized egg, 6 weeks have passed. What should I do?” The answer is simple - don’t panic ahead of time. If subsequent examinations reveal an embryo that is not increasing in size, this will give grounds to diagnose anembryony. If the embryo increases in size, then this will be a reason for joy.

As a rule, for a normal pregnancy, by six weeks the embryo is already noticeable.

What is a fertilized egg?

The sac is the structure surrounding the embryo (the fetus in its earliest stages of development).
Inside it, in addition to the embryo, there is amniotic fluid, which is a natural environment and protection for the developing fetus. It is this structure that is an indicator of the presence of pregnancy and its viability in the first weeks. After a missed period, a woman can take a pregnancy test, but the result of this test is not 100% proof that she is pregnant. A delay in menstruation is also not a reliable sign, as it can occur due to a number of other reasons, for example, inflammatory processes and other pathological processes in the organs of the reproductive system (after the delay, the fertilized egg was not detected).

It is possible to detect a fertilized egg in the early stages using a diagnostic method such as ultrasound, which gynecologists have recently given their preference to.

Visualization of the fertilized egg most often occurs at about five weeks of pregnancy, but its presence does not always guarantee the development of a healthy pregnancy.

In the middle of the fifth week, a specialist can examine the yolk sac inside the fertilized egg, which is the first source of nutrition for the developing fetus. If the fetal egg and yolk sac become visible in the ultrasound image, this is also not a guarantee of a healthy pregnancy, however, the absence of the latter may indicate serious pathologies in the development of the embryo.

Characteristics of the ovum that indicate problems in the development of pregnancy may include the following indicators:

• the fertilized egg does not grow as it should during a normal pregnancy (its growth until the 9th week of pregnancy should be about 1 mm per day);
• fertilized egg of irregular shape;
• absence of a yolk sac.

Reasons for the absence of an embryo in the fertilized egg.

Anembryonia is a fairly common phenomenon. What are the main reasons for the absence of an embryo in the fertilized egg?

Reasons for the absence of an embryo (empty fertilized egg).

There are actually a lot of reasons. Here are a few:

1. If the fertilized egg is without an embryo, the reasons may lie in various infectious processes, transmitted both by airborne droplets and sexually.
2. Numerous mutations in chromosomes can cause a situation where the fertilized egg grows but there is no embryo.
3. Disorders in the genetic apparatus.
4. Negative effects of chemicals.
5. Pregnancy during late menopause.
6. Constant stress.
7. Having bad habits: smoking, alcohol, drugs.
8. Hormonal disorders.
9. Negative influence of radioisotopes.

Dead fertilized egg

The saddest pathology of pregnancy development can be a dead fertilized egg at any stage of development. The causes of its death can be various diseases of the fetus, as well as elements of the fetal egg (placenta, membrane, umbilical cord), as well as a violation of oxygen metabolism in the embryo (fetus). The embryo may die due to insufficient yolk blood circulation for its nutrition, which results in oxygen deficiency, which leads to anomalies, as well as due to various infectious diseases of the fetus during intrauterine development.

The phenomenon of a dead fertilized egg is caused by the following diseases of a pregnant woman:

• cardiovascular pathologies;
• anemia;
• hypertension;
• severe kidney disease;
• infantilism;
• hormonal imbalance;
• high body temperature due to illness.

To prevent miscarriage, women at risk due to a history of these pathologies must be intensively monitored and, if necessary, hospitalized.

The main role in the death of the fetal egg belongs to hypoxia, which arose as a result of disruption of the uteroplacental-fetal circulation. In cases where a dead fertilized egg remains in the uterus, it becomes susceptible to maceration, mummification and petrification.

Anembryony of the second fertilized egg.

In medical practice, there is another formidable pathology called anembryony of the second fertilized egg. This disease is also very common in everyday medical practice. The same reasons described earlier lead to the occurrence of this pathology. The peculiarity is that a normally developing embryo will not be negatively affected by the second one.

In this case, an egg without an embryo is not dangerous. You just need to wait, because over time it will resolve itself, that is, it will undergo reduction.

Possible pathologies of the ovum

The first and most basic sign of a normal intrauterine pregnancy is the fertilized egg in the uterus. Using ultrasound, it is visualized a week after the missed period. In the first weeks, special attention is paid to its size, shape, location and the presence of detachments.

In the first trimester of pregnancy, the risk of spontaneous abortion (miscarriage) is highest. This phenomenon can be caused by genetic disorders in the child, a lack of progesterone, as well as pathological processes in the uterus and endometrium. The genetic failure cannot be corrected, and, alas, it is not possible to save the fetus; in other situations, medicine, as a rule, is able to help mother and child.

The normal shape of the fertilized egg is considered round or oval. If it takes on a shape with uneven corners, which means a deformed fertilized egg, a suspicion arises that the uterus is in good shape. In cases where there is no associated pain, cervical dilation, or bloody or brown vaginal discharge, this condition is harmless. When the muscles relax, the tone of the uterus most often decreases spontaneously, after a few minutes, after which the fertilized egg returns to its correct shape. Painful sensations associated with uterine tension are relieved by taking an antispasmodic drug. Isolated short-term cases of this nature are not a sign of a threatened miscarriage.

An ultrasound scan measures the diameter of the gestational sac in accordance with the weeks of pregnancy, dimensions in mm (for example, gestational sac 6 mm, gestational sac 7 mm). This helps to most accurately determine the gestational age and draw conclusions about how correctly the child is developing in the early stages.

Cases when, during an ultrasound examination, a fetal egg is detected without the presence of an embryo are called anembryony. The absence of an embryo in the early stages of pregnancy (from 1 to 2 weeks after a missed period) is considered normal; in later weeks, termination of pregnancy is recommended.

Anembryonia can be caused by an accidental genetic malfunction, which occurs mainly in women aged about 35 years, by taking medications that are contraindicated during pregnancy, as well as by exposure to other teratogenic factors.

Detachment of the ovum is considered more common and less hopeless than anembryonia, despite the fact that its manifestation is similar to a pronounced symptom of miscarriage - uterine bleeding. In order to minimize the negative consequences of this complication for the fetus, the woman is prescribed hormonal therapy with progesterone preparations and bed rest in a hospital setting.

A low position of the fertilized egg (if it is located in the lower third of the uterus) may be a threat to miscarriage.

Treatment of anembryonia.

In this article, we tried to explain the most pressing issues of pregnancy: why there is no embryo in the fertilized egg, the influence of the environment on the development of the embryo, the concept of anembryony, what is the essence of anembryony of the second fertilized egg, how this can affect a healthy embryo. As for treatment, if anembryonia is proven, the only treatment option is complete cleaning of the uterine cavity. After the procedure, a repeat ultrasound should be performed to monitor for possible complications. A new pregnancy is possible only six months after a total cleanse.

First of all, I would like to clarify that among such a pathological condition as anembryonia there are several types:

In the first case, there is no clear visualization of the fertilized egg and embryo, including a discrepancy between the growth parameters of the uterus according to the gestational age.

In the second case, in addition to the lack of development of the fertilized egg and embryo, there is active growth of the uterus according to the gestational age.

And the third type is characterized by cases, for example, in multiple pregnancies, when the development of one of the embryos is observed, when in parallel there is a frozen pregnancy of another embryo.

How to diagnose an empty ovum: hCG and its effectiveness

When there is an empty ovum, the hCG analysis will not be able to diagnose this. When pregnancy occurs, at first even the body itself does not suspect the presence of a disorder and fetal fading; the symptoms observed are the same as during the normal course of a child’s development:

• Fast fatiguability;
• Nausea, dizziness;
• Delayed menstrual cycle;
• Increased breast sensitivity, etc.

Of course, an empty fertilized egg cannot be left until the baby is born, so it is necessary to clean the uterus by performing curettage under general anesthesia. Of course, this is a complex medical operation, which previously quite often ended in heavy blood loss and infections. However, now medicine has stepped forward, so such manipulations should not cause concern.

After the operation, a repeat ultrasound is performed, and appropriate tests are performed on the removed tissue, which make it possible to identify the actual cause of the pathology. Pregnancy after an empty ovum should be planned no earlier than 6-12 months later; this period is enough for the body to rehabilitate, and future parents have enough time to prepare and plan the birth of the baby properly.

Why is the embryo not visible in the fertilized egg?

• This pathology can also arise as a result of chronic gynecological diseases that deform the structure of the uterine cavity (for example, endometriosis or uterine dysplasia); acute inflammatory or venereal diseases of the female reproductive system, which also do not occur without structural consequences, should not be excluded.

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Ultrasound at the 5th obstetric week of pregnancy

There are standard timings for performing ultrasound screening during pregnancy. For the first trimester it is 10-13 weeks, for the second – 20-24, for the third – 32-34 weeks. But in some cases, ultrasound diagnostics can be performed not only during these periods, but also earlier. Quite often, women are prescribed an ultrasound at 5 weeks of pregnancy. This is the period when the embryo can already be visualized and its heart begins to beat.

Why is an ultrasound performed at 5 weeks of pregnancy?

Ultrasound at the 5th obstetric week of pregnancy is performed for the purpose of:

• Confirm pregnancy. At 5 weeks, the pregnancy test should already show two lines, although rare errors do occur. To 100% confirm pregnancy, ultrasound screening can be performed.
• Confirm correct attachment of the fertilized egg. It must be fixed in the uterus, otherwise (for example, when the fertilized egg is fixed in the fallopian tube), an ectopic pregnancy is diagnosed.
• Assess the vital activity of the embryo in the fertilized egg.
• Detect multiple pregnancies.
• To refute the possibility that the increased level of hCG to which the pregnancy test reacted is not a consequence of a pathology of the female reproductive system.
• Identify threats of miscarriage.

As a rule, at such an early stage, ultrasound is prescribed for those women who:

• Previously had a caesarean section. In this case, you need to look at how the chorion (which will later become the placenta) is attached. Close attachment to a uterine scar or attachment directly to a scar can become a serious threat of miscarriage.
• Previously suffered miscarriages.
• Previously had a frozen or ectopic pregnancy.
• We became pregnant through the IVF procedure.

Diagnostics

There are quite a few diagnostic criteria for identifying anembryonia. A reliable sign of the absence of a developing embryo in the fertilized egg is visualization using ultrasound. Of course, there are cases when there is a pregnancy in the fertilized egg, but the embryo is not visible. This situation applies to short periods. However, if there is no embryo in the fertilized egg for 6 weeks or there is no embryo in the fertilized egg for 7 weeks, then we should talk about pathology.

A clear sign of unfavorable development of pregnancy, which indicates a pathology such as anembryonia, is the absence of the yolk sac when the size of the fertilized egg is 18.25 mm, and when its size exceeds these indicators, the absence of the embryo itself. If the fertilized egg is 5 weeks old, then the embryo is not visible, but if there is no embryo in the fertilized egg for 8 weeks, then in this case we can safely talk about the presence of such a pathology.

It is possible to assume that a pregnancy is not developing indirectly based on the level of human chorionic gonadotropin. Of course, hCG will tend to increase. This is the difference between anembryonia and frozen pregnancy, in which the hCG level will rapidly fall down. In the absence of an embryo in the fertilized egg, hCG will increase, but without the necessary dynamics. These indicators can be recorded at the lower limit of normal. This should alert the attending physician and be a reason to prescribe ultrasound diagnostics. A reliable diagnosis can be made at 7-8 weeks of pregnancy.

The condition during pregnancy in the form of the absence of an embryo is also classified into 3 types.

The first type is the absence of an embryo. This is a condition in which its remains are not recorded at all by an ultrasound diagnostic device; the size of the fertilized egg does not correspond to the gestational age.

Anembryonia of the second type is also characterized by the absence of any elements of the embryo, however, the uterus is fully consistent with the terms of pregnancy.

Anembryony of the second fertilized egg. Situations are also recorded when resorption of one embryo occurs. In one fertilized egg you can visualize a normally developing embryo, in another there is a complete absence of its elements. Of course, the main diagnostic criterion for anembryonia is ultrasound diagnostics.