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. Delayed menstruation is also not reliable sign, since 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 a delay ovum not detected).

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 normal pregnancy(its growth until the 9th week of pregnancy should be about 1 mm per day);
• fertilized egg of irregular shape;
• absence yolk sac.

Possible pathologies of the ovum

The first and most basic sign of 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 given 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 may be caused by genetic disorders in the child, 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 decreases most often spontaneously, after a few minutes, after which the fertilized egg returns correct form. Painful sensations problems associated with uterine tension can be relieved by taking an antispasmodic drug. Isolated short-term cases of this nature are not a sign of a threatened miscarriage.

Ultrasound 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 baby is developing. 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 occurrence, 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 the pronounced symptom of miscarriage - uterine bleeding. In order to minimize Negative consequences this complication for the fetus, the woman is prescribed hormonal therapy with progesterone preparations and compliance bed rest in a hospital setting.

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

Dead fertilized egg

The saddest pathology of pregnancy development can be a dead fertilized egg at any stage of development. The reasons for his death could be various diseases 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 anomaly, as well as due to various infectious diseases 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.

Diagnosis of the death of the fertilized egg

It is quite difficult to detect the early death of the fertilized egg and its retention in the uterine cavity, in the absence characteristic manifestations This requires dynamic observation. When severe symptoms: bloody discharge from the vagina, heavy bleeding, acute pain, the patient is urgently hospitalized.

The main feature non-developing pregnancy are: arrest of uterine growth, determined by repeated studies. It is recommended to test for hCG levels in the blood ( human chorionic gonadotropin human), the level of which constantly increases during normal pregnancy. Echo signs of a non-developing pregnancy during ultrasound may include the following indicators:

• lack of fetal heartbeat;
• the fertilized egg is wrinkled;
• no fertilized egg was found;
• “sleeping” uterine cavity.

If the fertilized egg has died, there is a disappearance of subjective symptoms of pregnancy: cessation of nausea, shrinkage of the mammary glands, lack of pigmentation of the areolas.

Fetal death in the second half of pregnancy is characterized by cessation of the heartbeat and movement of the fetus, delayed growth of the uterus, and also, in some cases, a crunching sound when palpating the skull due to separation and mobility of the bones.

Timely diagnosis will help to detect this pathology in time, which requires immediate hospitalization for further monitoring and prevention of complications.

If a doctor finds a fertilized egg in the uterine cavity during an ultrasound, then you can congratulate the woman on her pregnancy. This formation in the uterine cavity is the very first and the most important sign development of pregnancy.

The formation accommodates the embryo as well as amniotic fluid. Depending on the shape, size and location of the structure, the doctor determines the nature of the pregnancy.

Having learned about their pregnancy, many curious expectant mothers begin to ask the doctor questions about how and at what stage the fertilized egg is visible and what it looks like. We will try to answer them.

The fertilized egg, the diameter of which is very small in the first days of pregnancy, can be seen within two to three weeks after a missed period. The formed structure in most cases is located in the upper part of the uterine cavity, has a dark (gray) tint and a round or oval shape. The embryo at this time is still microscopic in size, so it is not detected.

Development and structure

The growth of the fertilized egg begins from the moment of conception. The fertilized egg begins to move along fallopian tube, during which cell fragmentation occurs. Making its way to the uterus, the fertilized, crushed egg needs nutrients and oxygen, so after a week a chorion begins to form on top, which subsequently transforms into.

The surface of the chorion has villi, which help the formation to attach to the uterus. In the future, these villi are contained only at the site of implantation of the formation into the uterine wall. The rest of the structure loses lint and remains smooth. The chorion provides the fetus with all vital important functions, one of which is protection against infections.

A value less than 7 mm indicates the middle of the fifth week. This is one of most important periods when active formation of blood vessels, heart and nervous system. The size of the embryo is usually 2 mm.

When an ultrasound shows a fertilized egg measuring 10 mm, this indicates that the heart and blood vessels are already fully formed and the embryo has a neural tube with a slight thickening at the end (the future brain).

6 obstetric week visualizes a value of 12 mm. At the 6th obstetric week, the fertilized egg is 12 mm in size, has a spherical shape, the embryo looks like white stripe about 5-6 mm long. At this point, the heart rate is 110-130 per minute. If any abnormality is detected during the sixth week, a repeat examination a week later is recommended.

To correct the situation, doctors remove it, after which the egg takes the correct shape. What the fertilized egg looks like during a miscarriage depends on the gestation period. At 1-2 weeks, a miscarriage may look like bleeding menses. For more later the formation looks like a blood clot. If a miscarriage occurs at 7-9 weeks, the woman may find pieces of fetal tissue.

If the structure has an oval and at the same time flat shape, this may also indicate. However, in the absence of pain and other ailments, it makes sense to continue monitoring the pregnancy. Repeated examination will allow the doctor to draw the correct conclusion.

Wrong location

A low gestational sac does not indicate a serious pathology, but requires more careful observation throughout pregnancy. If the formation is very close to the cervix, then cervical pregnancy may occur, which can lead to removal of the uterus.

Empty fertilized egg

When you can detect an empty fertilized egg, when the cavity contains only liquid or a blood clot.

Types of ultrasound. What are SVD and KTR?

To determine the parameters of the fertilized egg, different kinds Ultrasound:

• Transabdominal - examination occurs through the outer abdominal wall.
• Transvaginal – examination is carried out through the vagina.

During TA examination, clear identification of formation is possible starting from 5 obstetric week. At this time, the fertilized egg is 5-8 mm in size. Using the second research method, you can determine the size of the fertilized egg on the 3-6th day of missed menstruation, which is 4-5 weeks of gestation.

The embryo is visualized starting from the 5th week of pregnancy during a TV examination, and during TA - from the 6th week in the form of a linear formation.

To assess the size and growth of the formation and embryo, the following indicators are used:

• SVD is the average internal diameter of the fertilized egg.
• KTR – coccyx-parietal size embryo/fetus.

SVD shows the size of the fertilized egg by week and is measured in millimeters. So the indicator of the size of the fertilized egg constantly varies by week of pregnancy, it is more accurate to determine reliable period gestation is an indicator of CTE.

At this study the error may be three days up or down. Basically, the study is carried out up to 12 weeks of gestation.

The size of the fertilized egg helps to quickly determine how far along the pregnancy is and how the fetus develops in the womb.

The first three months of development are the most important, because it is during this time that all the organs and systems of the future baby are actively developing. Accordingly, it is important to undergo a scheduled ultrasound on time, which helps to identify possible deviations and spend optimal correction the situation.

Useful video about ultrasound in early pregnancy

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Today, such pathology as anembryonic pregnancy (anembryonic pregnancy) or an empty fertilized egg is becoming more and more common. Anembryony is the absence of an embryo in the fertilized egg. Eat membranes, amnion (water membrane), chorion (villous membrane), but no unborn child (embryo).

Some of these pregnancies are terminated on their own. early stage before implantation into the wall of the uterus - this is how the body gets rid of the defective embryo. But if the fertilized egg manages to attach to the wall of the uterus, then its chorion begins to produce hCG, as in normal pregnancy (see “HCG during pregnancy”).

Therefore, with anembryonia, a woman experiences a delay in menstruation, and there may be signs of pregnancy such as nausea, changes in taste, fatigue, and breast swelling. Since pregnancy tests are based on determination of hCG, they will be positive.

However, anembryonic pregnancies cannot develop normally and always end in miscarriage in the first trimester.

Empty fertilized egg (anembryonia) causes.

The main reason for the appearance of anembryonia or an empty fertilized egg is chromosomal and genetic abnormalities. Most often they arise spontaneously at the time of cell division, that is, in the first days after fertilization. During the division of the cells responsible for the formation of the embryo, a malfunction occurs and the embryo is not formed, while other cells continue to develop and create an empty fertilized egg.

There is another situation when the embryo is formed, but dies in the early stages of pregnancy and it is so small that it is not visible on ultrasound.

Signs of anembryonia.

Pregnancy with an empty fertilized egg may have the same symptoms as normal pregnancy. However, with anembryonia, spotting and spotting is often observed, as the uterus tries to get rid of the defective fertilized egg.

An empty ovum can only be determined using ultrasound. However, it is not recommended for all women to undergo an ultrasound in the early stages; such an examination should be carried out only when indicated, for example, in the presence of bloody discharge or severe pain in a stomach.

An ultrasound performed too early can give an erroneous result and add unnecessary stress to a pregnant woman’s life. There are often cases when the diagnosis of “anembryonia” turns out to be false. An ultrasound was performed very early or the gestational age turned out to be shorter than expected, and the small embryo was simply not seen.

It is possible to determine anembryonia by ultrasound no earlier than 5-6 weeks of pregnancy, but even at this period there may be errors.

Anembryonia: what to do.

If anembryonia is suspected, one should not rush to terminate the pregnancy. Firstly, the diagnosis may be false. Definitely need to do one more ultrasonography in about 7-10 days.

Secondly, if the diagnosis is confirmed, it is recommended to wait 2-3 weeks. Cleaning is required in very rare cases; most often, an empty fertilized egg comes out of the uterine cavity on its own. Basically, spontaneous termination of pregnancy with an empty ovum occurs up to 8 weeks.

Only in some cases may instrumental removal of the fertilized egg be necessary. It's also possible drug interruption anembryonic pregnancy, when a woman takes certain medications and the fertilized egg comes out on its own.

It is worse when, when bleeding occurs, the doctor prescribes progesterone and other drugs to maintain pregnancy and this prevents the evacuation of the defective fertilized egg. In such cases, the likelihood of surgical termination of pregnancy (cleaning) increases.

Pregnancy after anembryony.

In most cases, anembryony occurs accidentally due to defective conception and does not recur. If the empty ovum repeats more than two times in a row, the couple needs to be examined. A woman needs to start with an examination thyroid gland. Thyroid can produce antibodies that penetrate the embryo and lead to its death.

Repeated anembryonia can occur due to pathological sperm, so a man must have a spermogram. After three pregnancy losses, the couple is also advised to undergo genetic counseling.

It is impossible to prevent anembryony. Anembryonia can occur at any age in completely healthy women. If you do not interfere with the natural course of events and do not take drugs that maintain pregnancy, then anembryonia ends in most cases spontaneous interruption in the early stages and does not affect subsequent pregnancies.

Immediately after the good news about interesting position the woman begins to worry and take care of the developing baby. Doctors come to her aid - at the end of the first month of pregnancy, the fertilized egg can already be seen on an ultrasound. Changing its size by week allows you to draw conclusions about whether the pregnancy is progressing correctly.

Fertilized egg: what is it and why keep an eye on it?

A fertilized egg is a fertilized egg surrounded by membranes. It constantly undergoes division - first into 2 parts, then into 4, etc. As a result of this process, the size of the embryo constantly increases. Before fixation in the uterus, which occurs 7 days after conception, the fertilized egg receives the necessary substances from the yolk sac. The term “gestational sac” changes to “fetus” after 12-14 weeks of pregnancy.

Tracking the size of the ovum week by week is not a whim or a safety precaution for scrupulous doctors and their patients. This information helps:

• determine the duration of pregnancy;
• name the expected date of birth;
• make sure that the growth of the embryo is normal;
• detect the appearance of pathologies;
• prevent involuntary termination of pregnancy, that is, miscarriage.

Do not put off ultrasound examination until later. After all, the woman herself, who is preparing for imminent motherhood, is primarily interested in obtaining the above information.

What numbers create a “portrait” of a tiny embryo?

Medical science has long known the norms various indicators development of the fertilized egg in the first 3 months of expecting a child. When examining the embryo visualized on the monitor, the doctor will first of all pay attention to its shape - to minimum period it resembles a circle. Next, you need to measure the internal diameter of the fertilized egg and tell the woman how long the long-awaited “resident” has been inside her. But this diameter is not the same for everyone, as it depends on individual characteristics body. Therefore, if, when establishing the time elapsed after conception, we rely only on this indicator, an error of 1.5 weeks is possible.

Thanks to modern transvaginal ultrasound devices, it is possible to detect a fertilized egg measuring 2-4 mm. What period does this measurement confirm? No more than 2-3 weeks after the start of development and 5-6 weeks from the date of the last menstruation.

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How will this indicator change in the future? We offer a small “cheat sheet”, which indicates the development period, and in brackets - the period from the moment of the last menstruation:

• 5 (8) weeks - 6 mm;
• 6 (9) weeks - 11-18 mm;
• 7 (10) weeks - 19-26 mm;
• 8 (11) weeks - 27-34 mm;
• 9 (12) weeks - 35-43 mm;
• 10 (13) weeks - 50 mm.

But what women hear during an ultrasound cannot always be found in the standard list of sizes. Therefore, expectant mothers often have questions - for example, if the fertilized egg is 5 mm, what is the gestational age? This is about 5 weeks. What is the period if the fertilized egg is not 5 mm, but 8 mm? Then the pregnancy is 5 weeks and a few days. During the day, the egg cell surrounded by the membrane will grow by an average of 1 mm, and after crossing the milestone of 15 weeks, the fetus increases by 2-2.5 mm daily.

To make sure that everything is fine with the unborn baby, in addition to this data, they measure the area and volume of the fertilized egg, as well as the diameter of the yolk sac. The norm of these indicators varies by week.

No less important information is KTR and BPR. How to decipher these abbreviations?

The coccyx-parietal size (CPR) is the length of the embryo from its top to the coccyx. Such measurements make it possible to determine the time of pregnancy as accurately as possible, because the indicator is almost identical in all patients.

Biparietal size of the fetal head (BPR) is the area from the surface of the upper border outside to the surface of the lower border inside between the parietal bones. BDP is measured starting 6 weeks after conception.

The following table will help you understand how normal the ultrasound results are.

When is women's anxiety justified?

A woman who has recently learned about her new position does not always hear on ultrasound good news. What could darken her hope for successful motherhood?

Irregular shape

Before the 5th-6th week of pregnancy, the doctor sees the fertilized egg in the form of a rounded figure. But when the baby’s gestation period approaches 2 months, during a longitudinal scan the embryo will look oval, although during a transverse scan it will remain round. Other deviations from normal shape. This pathology most often develops in the presence of neoplasms in the uterus or partial detachment of the placenta.

Placement violations

The fertilized egg should be fixed in the fundus of the uterus or on its posterior wall, less often - in internal os or at the top of the organ. If the embryo is positioned differently, the doctor assesses how dangerous it is and decides on future fate crumbs.

Size pathologies

If the egg in the membrane is smaller or larger in size than the above values, this indicates possible violations development. But since these indicators can fluctuate even with normal course pregnancy, only a specialist can make a conclusion about how significant the deviations are.

False ovum

When ectopic pregnancy The doctor can still see the fertilized egg in the uterine cavity. But in fact, this formation consists of an accumulation of mucus and secretion from the glands of the fallopian tubes. You can recognize the “deception of the body”: this egg will differ in wall thickness and shape from a normal fertilized egg.

Empty fertilized egg

At 1-2 weeks the fetus is not yet noticeable, so it will not be possible to understand whether it is developing. But empty egg at a later date - warning sign. Most likely you will need medical interruption pregnancy. Among the reasons for this sad situation are the age of the woman, genetic disorders, taking medications that are contraindicated for pregnant women.