How many days does embryo implantation last? Is it possible to engraft two embryos on different days? Why can rejection happen?

Today families who naturally can't, resort to. This procedure is expensive and complicated, but if it is successful, the married couple will become happy parents in 9 months.

In vitro fertilization consists of several stages, the most important of which is the implantation of the embryo into the woman’s body. This procedure is not considered difficult, but in order for pregnancy to occur, everything must be done strictly according to the rules of both the doctors and the woman.

Examination before embryo implantation

Before a fertilized egg is implanted into the body, a woman must undergo examinations. Thus, the condition of the uterus, its length and wall thickness are studied. If muscle tone is observed, the woman is prescribed relaxing medications before IVF.

Before implantation, it is necessary to determine the condition of the uterine walls. They must contain the nutrients required for fetal development. If some substances are missing, pregnancy may not occur.

Before embryo implantation takes place, a woman must undergo hormone tests. In her body there must be sufficient quantities necessary for normal gestation.

Before implantation, the embryo is also examined. Of all the fertilized cells, reproductologists select only healthy ones. After all, already at this stage it is possible to diagnose genetic diseases in the embryo.

But even if the procedure was carried out without violations, embryo implantation may not occur. This happens for various reasons. The embryo may have some genetic disease, not diagnosed before egg transfer. Often these diseases prevent pregnancy from developing.

The reason may be painful condition uterus, due to which the embryo cannot attach to it. It could also be infection or mechanical damage, applied by the instrument during cell transfer.

Timing of embryo implantation

When a fertilized egg enters the female body, it must move through the fallopian tube. Counts normal conduct embryo implantation on the seventh day after artificial insemination eggs. If the procedure is successful, the embryo should attach to the wall of the uterus within 40 hours. After attachment, it begins to develop in the same way as an embryo that appears naturally.

Doctors never rule out late embryo implantation, which occurs 10 days after the fertilized egg is implanted. That's why married couples It is recommended to believe in the success of the procedure until the last moment, because pregnancy can occur even when it is not expected.

After embryo implantation, the amount of human chorionic gonadotropin increases in the blood. It is from the moment the level of this hormone increases that the embryo can be visualized on ultrasound. Therefore, late implantation of the embryo cannot be ruled out and hCG should be done periodically - this will allow time to determine the onset of pregnancy and begin to monitor the development of the baby already at early stages.

Signs of successful embryo implantation

After successful implantation of the embryo, the woman begins to experience certain sensations that she did not have before. At first, her breasts begin to hurt slightly and become enlarged. Pain is felt in the lower abdomen. A sign of implantation of the embryo into the uterus is not acute, but dull and nagging pain.

An important symptom of embryo implantation is the appearance of pink or dark brown colors. They often indicate pregnancy.

Sensations during embryo implantation may be similar to symptoms food poisoning. Always present in the mouth metallic taste, when you see food you feel sick and start vomiting.

Signs of embryo implantation into the uterus are:

• irritability,
• dizziness,
• weakness,
• headache,
• prostration,
• excessive emotionality,
• mood swings,
• depression

Don't confuse pregnancy with a cold. After all, with successful implantation, chills and an increase in temperature to 37 and 3 may be observed for several days. If you are expecting pregnancy and the temperature begins to rise, you should not take antipyretics and antiviral drugs– this can harm the embryo and terminate the pregnancy.

After IVF, a woman needs to listen especially carefully to her body. If you do experience any of these symptoms, it is necessary to find out for sure whether you are pregnant or not.

Regardless of whether embryo implantation occurred naturally or artificially, it has the same type of symptoms: pain in the lower abdomen, nausea, bleeding, dizziness. In any case, if you have such symptoms, do not delay going to the doctor, because early examination can prevent miscarriage and the development of pregnancy pathologies.

Collapse

The process of embryo implantation occurs a few days after the egg has been fertilized by a sperm. During it, the fertilized egg attaches to the wall of the uterus, to its mucous membrane - the endometrium. This process may be accompanied by a certain characteristic symptoms, noticeable both visually and perceptibly. However, such symptoms may not be present, because diagnostic sign she is not. However, sometimes sensations during implantation of an embryo into the uterus play an important role in diagnosing the course of the process, especially in cases where they do not correspond to acceptable values.

Definition

Implantation is a process in which a fertilized egg, which has spent some time freely in the uterine cavity, is finally attached to the endometrium of its cavity with the help of special spines. It is in this place that the fertilized egg, and then the fetus, will remain and develop throughout the pregnancy, and it is there that the placenta will form, initial stages presence which are visible already at the attachment stage.

Feelings during the implantation process

What sensations do you experience when an embryo is implanted into the uterus? It is important to understand that when the fertilized egg is attached, which occurs approximately a week after fertilization of the egg or after the embryos have been transferred into the uterine cavity (during in vitro fertilization), the endometrium is injured by the spikes of the fertilized egg. Although such an injury is minor, it can nevertheless be accompanied by certain symptoms. But symptoms, whatever they may be, occur only in 30% of cases, and in 70% of pregnancies the woman does not notice the passage of this stage:

The attachment has the following external signs:

• Bloody discharge, very slight normally, for just a few hours or all at once;
• Blood in normal vaginal discharge.

A number of subjective signs may also appear. These are sensations after embryo implantation such as:

1. Mild pain in the lower abdomen (sometimes can increase to moderate intensity), lasts 2-3 days;
2. Feeling of heaviness in the lower abdomen;
3. Some tingling sensations are felt in the mammary glands;
4. An unpleasant metallic taste may be present in the mouth for about one day;
5. Mild nausea or subjective and very minor signs of food poisoning;
6. An increase in body temperature to approximately 37.5 degrees without deterioration in health.

From the outside general well-being possible symptoms such as increased fatigue, general weakness and deterioration in health.

Feelings after implantation

The implantation itself occurs in approximately less than one day. But several unpleasant symptoms persist even after it, for example, they may be present for another one or two hours bloody issues. Also, heaviness and pain in the lower abdomen may continue to be present for a couple of days. Tingling in the chest becomes more or less permanent. Nausea appears in the form that is characteristic of pregnancy.

Transfer of embryos into the uterus during in vitro fertilization more often it is not accompanied by any symptoms, since the organ is more prepared for the changes that will occur than with natural conception.

Deviations from the norm

Deviations from the norm may include pain and bleeding that persist 10-12 days after ovulation, that is, several days after implantation of the embryo into the uterus. Besides, alarm signal a strong increase in temperature is indicated, as this may indicate that the symptoms are caused by inflammatory process, and not by the attachment of the fertilized egg.

The absence of any sensations both during attachment and after it has taken place is not considered any negative symptom. This normal condition body.

Infusion for IVF

Conclusion

The presence of any sensations during implantation should not be considered a reliable sign of the presence or absence of pregnancy. The attachment of the embryo may or may not be accompanied by any symptoms. Simply put, if pain there was no ovulation a week after ovulation, this does not mean that the woman is not pregnant. Just as their presence can be caused for various reasons, including pathological ones.

You should pay attention to signs that deviate from the norm. Because they can be either a sign of abnormal implantation during conception, or a sign of some pathology in the absence of conception. If symptoms appear that clearly do not correspond to the norm, in any case you should immediately consult a doctor, regardless of whether the patient planned pregnancy or not.

It’s simply amazing how many changes the female body undergoes and how many tests they go through male sperm so that it becomes possible conception child. The egg in the ovary during long period matures, which becomes possible only with certain conditions. Out of millions of sperm, only one will be able to fertilize her, if he is good enough for this. The meeting of the treasured cells can only happen if there is good traffic fallopian tubes. And then, after they merge together, the future fetus still has to go through a difficult path to the uterus. But this is not the end. You can talk about a completed pregnancy no sooner than the implantation of the embryo occurs.

Implantation of the embryo into the uterine wall

As soon as the fastest sperm penetrates the wall of the egg, it will be covered with a specific membrane that is impenetrable to others and will remain in it all the time until it reaches the uterine cavity. From the moment of fertilization, the fertilized egg begins to rapidly divide, forming more and more cells. It moves through the fallopian tubes up to the uterus, which is facilitated by contractions of the fallopian tubes and the villi located on their walls: they roll the egg like a ball.

Having reached the uterine epithelium, the fertilized egg sheds its protective membrane, exposing the trophoblast, which helps to attach itself to the wall of the uterus and then participates in the formation of the placenta. If the membrane is too dense, implantation may not take place. As a rule, only a healthy blastocyst without genetic disorders manages to attach itself to the uterine lining - it works natural selection. An embryo with serious pathologies at this stage is rejected by the female body - and the pregnancy fails.

In general, the cause of failed implantation of the fertilized egg may be violations from female body or from the blastocyst cells:

• the protective membrane of the fertilized egg is too thick;
• genetic disorders in blastocyst development;
• inconsistencies of the uterine epithelium (its thickness for successful implantation should be 10-13 mm);
• insufficient level of progesterone in the female body (it creates the necessary conditions for consolidation and further development of the fertilized egg);
• deficit nutrients in the tissues of the uterus.

As soon as the embryo is firmly established, the level of hCG in the mother’s blood and urine will begin to rapidly increase and appear early symptoms pregnancy.

On what day after ovulation does embryo implantation occur: timing

It takes about a week for a fertilized egg to reach a woman's uterus. But these terms may not be the same in each individual case. The duration of the process is influenced by the condition and viability of the fetal egg, the patency and functionality of the fallopian tubes, hormonal background in the female body and so on. IN in some cases early or late implantation of the embryo occurs.

In general, doctors say that the fertilized egg attaches to the uterine epithelium between 6 and 12 days after ovulation. This may be a few days before the expected start of your next period.

The entire process of implantation of the blastocyst into the uterine mucosa lasts from several hours to 3 days. On average it is about 40 hours. During this period, the fertilized egg “pulls out” a nest for itself, in which it will “take root” - the trophoblast of the egg will penetrate the tissue of the uterus, taking root in it. As the “construction work” progresses, the blastocyst can take breaks for itself: the process of implantation is either suspended or actively continues again. In this regard, some sensations during the period of embryo implantation in a woman may also occur sporadically.

The implantation period is life-changing. If the fertilized egg manages to gain a foothold, then it will almost certainly also be able to overcome all other difficulties that may arise in the future. If the fetus turns out to be weak or sick, then most likely the pregnancy will be terminated at this stage.

The female body perceives the cells of the unborn child with hostility: they carry foreign genetic material. And therefore on initial stages As pregnancy progresses, it (that is, the body) will try to get rid of such an invasion. That is why it is very important that a woman who is very eager to become pregnant behaves with extreme caution during the period of embryo implantation.

Embryo implantation: symptoms, signs, sensations

How do you know that such things are happening in your body? important events? Most women do not feel any special sensations. Many are ready to see symptoms of embryo implantation in any changes and even in their absence. Meanwhile, doctors confirm that in fact, during the hours or days when a fertilized egg is implanted into the uterus, certain sensations may occur. But they should be assessed truly objectively, and, of course, with to a greater extent A woman expecting or suspecting pregnancy in her last cycle is likely to notice such signs.

So, the most common symptoms of embryo implantation may be as follows:

• Implantation bleeding. It is the discharge of a very small amount of blood from the vagina (literally no more than a few drops), which colors the leucorrhoea in a reddish, beige or brownish color. “Bleeding” occurs due to damage to small vessels during the implantation of the embryo into the uterine epithelium.
• Nagging pain in the lower abdomen (or tingling). Some are weaker, unobtrusive, some are quite strong, noticeable, but many women feel pain in the lower abdomen during the implantation period. They are usually localized at the point where the egg is attached.
• Increase in temperature - both basal and body temperature. And throughout the first trimester, and even now, in the first days of pregnancy, the temperature may remain at elevated subfebrile levels. This is one of the reactions of a woman’s body to pregnancy.
• Implantation retraction. A short-term decrease in basal temperature before its further persistent increase to subfebrile with high degree probability allows one to suspect pregnancy. It is during the implantation period that BT decreases by 1-1.5 degrees, which is why this phenomenon got its name - implantation retraction.
• Metallic taste in the mouth, nausea. Sometimes women confuse this condition with poisoning.
• Weakness, malaise. A woman may feel a loss of strength, dizziness, and apathy.
• Mental instability. Mood and emotions quickly, suddenly and without reason replace each other in opposite directions. Often a woman feels an increased need for love and attention to herself, begins to feel sorry for herself, whine, and become despondent.

Implantation bleeding: discharge

We have already talked about implantation bleeding, but this feature should be discussed in more detail. The fact is that already in the first weeks of pregnancy there may be a threat of termination. At the same time, against the background of nagging pain in the lower abdomen, bloody discharge of various shades of red comes from the vagina. In addition, smearing and bleeding can also be due to sexually transmitted infections or gynecological diseases.

Observing such discharge in themselves, some women think that this is implantation bleeding. But these states should be clearly distinguished. When an embryo is implanted, the discharge looks completely normal, with the only difference being that sometimes (rather rarely!) you can see bloody spots in it, or a very small drop of blood will appear on your panties. If the spotting looks different, you should immediately consult a doctor.

Implantation bleeding, despite its name, has nothing to do with bleeding and is completely unlike it.

Embryo implantation during IVF

IN Lately More and more couples are turning to the services of fertility specialists to become pregnant. In this regard, the question arises of how embryo implantation occurs after IVF. There are almost no differences from natural pregnancy in this regard: the entire process of implantation of the fertilized egg occurs according to the same scenario, a woman may or may not observe the same sensations in herself, similar to the first signs of pregnancy in the early stages.

However, embryo implantation during IVF may have some peculiarities. Due to the fact that conception occurred outside the mother's body, planted in female uterus the embryo may feel the need to adapt to new environmental conditions. For this reason, the implantation of embryos (and several of them are implanted at once to increase efficiency) ends successfully in only about a third of all cases. If implantation of the fertilized egg does occur after IVF, it is often late and lasts longer than usual. In addition, in order to minimize the risks of non-survival, to the expectant mother you should be careful:

1. Get more rest and sleep at night.
2. Avoid physical and nervous stress, do not lift heavy objects.
3. Refrain from taking hot baths and showers, or having sex.
4. Avoid overheating and hypothermia of the body.
5. Eat well.
6. Take leisurely walks in the fresh air.
7. Eliminate effects on the body harmful factors(household and industrial chemicals, for example).
8. In season viral diseases do not visit crowded places.

In general, you need to take care until the 20th week of pregnancy: during this period, the placenta is already fully formed, and the fetus receives additional protection. From the point of view of obstetrics, implantation lasts throughout this entire period, and only then the active growth of the baby begins.

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Women who are planning a pregnancy have probably heard about implantation, but not everyone knows exactly how and when this important process occurs. In the meantime, it is the success of implantation that determines whether the pregnancy will develop further or end on its own. early stage when a woman does not even suspect that there is new life inside her. In this article we will talk about when implantation occurs and how long it lasts.

How does this happen?

Implantation is the process of implantation of a fertilized egg into the wall of the uterus, where the fetus will grow and develop throughout gestation. Before this happens, conception itself must occur.

On the day of ovulation, a mature female is ready for fertilization sex cell leaves the follicle on the ovary into the ampullary part of the fallopian tube. This is where fertilization occurs. Sperm may already be in the tube by this time if sexual intercourse took place before ovulation, or they may reach their destination within 24 hours after ovulation. This is how long the egg lives and retains the ability to fertilize.

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As soon as the meeting of male and female gametes occurs, the process of transforming the egg into a zygote begins - a special new cell, containing an individual set of chromosomes borrowed from the sperm and oocyte. Female and male chromosomes fuse to form new life. The zygote begins to split into new cells, the number of which increases constantly. At the same time, it begins to move towards the uterus, because only there nature has provided optimal conditions for the development of the fetus.

At this stage, the embryo is inactive; villi on the inside of the tube itself, as well as slight spontaneous contractions of the walls of the fallopian tubes, help it move forward along the tube. This journey takes from 3 to 5 days. On day 5, the fertilized egg finally descends into the uterine cavity and begins to look for a “shelter”. She can swim in the uterus for another day or two, all this time crushing continues. Two layers are formed: the inner one, from which embryonic structures will then be formed, and the trophoblast - the outer layer, which will take responsibility for implantation.

The egg becomes a more complex structure - a blastocyst. At this stage, it is very important for her to stick to the wall of the uterus. Once the fertilized egg attaches to the uterus, the implantation process begins. By simple mathematical addition it is easy to establish that 7–8 days usually pass from the moment of ovulation to the start of implantation. Sometimes implantation occurs only on days 8–9, and this is also considered quite normal.

The implantation itself lasts about 40 hours. Sticking, the initial attachment to the wall is called the adhesion stage. After this, the second stage begins - invasion (immersion). Troboblast forms special very thin villi. These thread-like “tendrils” begin to secrete enzymes that dissolve the endometrial cells of the uterus.

Gradually, the villi go deeper and deeper into the uterine tissue. A depression is formed into which the fertilized egg is securely immersed. The villi are connected to blood vessels maternal organism, and the embryo, which previously fed only on what was in nutrient medium the uterine cavity begins to receive everything it needs from the mother’s blood.

At the same time, the production of a special hormone begins, the presence of which is practically excluded in the body of a non-pregnant woman. healthy woman, - human chorionic gonadotropin. It is hCG, when the concentration of the substance reaches a sufficient level in the body, that will allow you to do a test or blood test for pregnancy. Its level increases gradually, and already 4 days after implantation or 10 days after conception, a blood test for hCG can answer the question of whether pregnancy has occurred. Test strips in urine will detect hCG from the first day of delay, that is, 14 days after conception.

If implantation is successful, pregnancy occurs, the development of the embryo continues, hormonal levels change, and the woman becomes pregnant. If unforeseen circumstances arise at at least one of the stages of attachment of the fertilized egg, pregnancy will not occur: the fertilized egg will die and come out along with fragments of the endometrium during the next period.

Early and late attachment

If the fertilized egg passes unhindered through the fallopian tubes, with normal speed fragments and develops, then implantation may be early. In medicine, this is considered to be the complete immersion of the blastocyst into the endometrium before the 7th day after ovulation.

If the lumen of the fallopian tubes is narrowed, progress along the fallopian tube is slow, the cells of the embryo are not dividing quickly enough, the endometrium is not thick enough, and the implantation process may be delayed. Late attachment is considered to be implantation that occurred after 9 days from the moment of ovulation.

Implantation time according to by and large does not affect further development pregnancy, but late and early attachment still have their own nuances.

• Early implantation is prognostically worse than late implantation, since the fertilized egg may descend into the uterus too early, when the endometrium has not yet reached full readiness Accept him. In this case, implantation either does not occur, or occurs, but with certain defects, which later, at a more serious stage of gestation, can result in placental insufficiency, abruptions and abnormalities in the development of the placenta, or all result in early miscarriage.
• Late implantation is more favorable due to endometrial maturity, but too late the “arrival” of the fertilized egg can again result in a lack of implantation, because special structures of endometrial cells - pinopodia - appear only during the “implantation window” and disappear after a couple of days until the next menstrual cycle. Without them, the immersion stage will be much more difficult and may end in failure.

Some features of timing

If a woman becomes pregnant in a natural way, but through IVF, the countdown of the expected timing of implantation begins not from the moment of ovulation, because it does not occur in an IVF cycle, but from the day after the embryos are transferred into the uterine cavity.

In general, the implantation process itself after IVF lasts slightly longer than 40 hours, and it begins later. 5-day-old embryos implant the fastest and best; three-day-old embryos implant a little worse. The first ones can begin to attach within a few hours after transfer. The second sometimes takes about 3-4 days just to begin to delve into the endometrial layer. After cryotransfer, implantation is almost always late.

A blood test for hCG, in order to understand whether implantation has taken place and whether pregnancy has occurred, is recommended to be carried out no earlier than 14 days after embryo transfer.

According to statistics, three-day embryos take root with a 40% chance, five-day embryos with a 50% chance, and two-day, six-day and older embryos are successfully implanted no more often than in 20–25% of cases.

Implantation during IVF, at first glance, is no different from the attachment of an embryo to the uterine wall after natural conception. For patients there is no noticeable difference between these conditions. However, embryologists and reproductive specialists know for sure that the process of transferring an embryo into the uterine cavity has many nuances. If certain conditions are not met, the biological chain will be disrupted, resulting in the protocol failing. In order to increase the likelihood of embryo implantation, the patient should follow the doctor's recommendations.

During natural conception, all processes in the pelvic organs are controlled by hormones. The hypothalamic-pituitary-ovarian system regulates the production of the necessary substance on a certain day of the cycle. The follicle that develops after menstruation reaches its maturity and ovulation occurs. When the egg leaves the ovary and moves into the cavity of the fallopian tube, many sperm rush towards it. Only one can fertilize a female gamete. In the process of natural selection, it defeats other cells. When fusion has occurred, a fertilized egg is formed. By continuing to share, it advances in its goal. Having attached itself to the uterus, the embryo begins to receive oxygen and nutrients through the mother's blood.

When using assisted reproductive methods, doctors face important task. Fertility specialists need to determine the most favorable time to perform the transfer. The further implantation process will depend on the accuracy.

After the puncture of the eggs, the patient is transferred to hormonal support, which creates conditions for the body in the second phase of the cycle. The transfer will take place over the next few days. Time is calculated as if the fetus is passing natural way By fallopian tubes, as a result of which it ends up in the uterus. Implantation is divided into two stages:

• adherence or adhesion - a set of cells attaches to the functional layer of the uterus;
• immersion or invasion - the fertilized egg is embedded in the tissue in a burrowing manner.

After the completion of the natural process, the depression that the embryo formed is tightened, and the fertilized egg is completely immersed in the mucosa. From this moment, pregnancy begins to develop.

On what day after the transfer does embryo implantation occur?

In vitro fertilization allows you to choose a specific day when the embryo will enter the uterus. At this stage, the main task of embryologists is to establish the time of the implantation window. This term refers to a condition of the uterine mucosa in which the most favorable conditions for embryo attachment. The process of formation and existence of the implantation window has not been thoroughly studied. Experts continue to study the factors influencing it.

The time of implantation after embryo transfer completely depends on the method of carrying out the protocol, the chosen hormonal support, and the duration of stay of the germ cells outside the woman’s body. The peak receptivity of the mucous layer usually occurs 20-21 days after the last menstruation. When using certain hormone regimens, it may shift.

Implantation of the blastocyst takes place from 6 to 10 days after fertilization. In gynecology, there is a concept of early and late introduction of a genetic set into the uterine wall. When performing IVF, the blastocyst is completely attached within 3 days, whereas in the process of natural conception this time does not exceed 40 hours.

After replanting for three days

If a woman has three-day-old embryos (morula) transferred into her uterus, then for some time they will still remain unattached in the cavity of the reproductive organ. During this period, cells continue to divide, and their own membrane feeds them. Within 2-4 days after the transfer, the process of implantation of the embryo into the uterine mucosa will begin.

After replanting for five days

Depending on the individual characteristics of the patient and the method of performing the protocol, transfer of five-day-old embryos (blastocysts) may be carried out. It is considered more preferable if many cells were obtained during the superstimulation process. There is an opinion that even with in vitro fertilization, natural selection plays a significant role. For this reason, high-quality embryos survive until the age of 5 days. After the transfer of the blastocyst, implantation of the embryo occurs during IVF within a few hours. The attachment process begins as soon as the cells enter the cavity of the reproductive organ and is completed after 1-3 days.

After cryotransfer

In cryoprotocol with natural cycle Implantation usually occurs on days 20-23. For this IVF technique, women with regular menstruation and good hormonal levels are selected. Therefore, the possibility of failure is practically eliminated. Important role plays the age of frozen embryos. Among them there may be three-day and five-day cells. During cryotransfer, the following factors play a determining role in the implantation time:

• age of transferred embryos;
• possibility of carrying out the protocol in a natural cycle;
• the need to use replacement therapy;
• characteristics of the patient's body.

How to increase the chances of successful implantation during IVF

To increase the chances of a positive completion of the protocol, it is necessary to determine the time when endometrial receptivity will be maximum. For this purpose, doctors monitor the condition of the patient’s pelvic organs using ultrasound and correct them with hormones. An important point At the transfer stage, the implantation window will be established.

Strict adherence to basic medical recommendations increases the chances of successful embryo implantation during IVF:

• exclude sudden temperature changes, do not visit baths and saunas;
• do not swim in public bodies of water or take a bath;
• maintain sexual rest;
• don't expose yourself physical activity and do not lift heavy objects;
• do not douche or use tampons;
• during the first 2-3 days, rest more;
• from 3-4 days spend sufficient time in the fresh air;
• avoid viral infections;
• eat nutritiously and drink at least one and a half liters of clean water.

It is especially important for the patient to take medications prescribed by the doctor. Progesterone support has a significant impact on the condition of the uterus, endometrium and promotes proper attachment of the embryo. If a woman does not take medications, then even if all the rules are followed, the chances of getting pregnant will tend to zero.

Symptoms, signs, sensations

If the cell transfer coincides exactly with the moment when the implantation window opens, then in the near future the woman may learn about her new position. All patients who have undergone in vitro fertilization are looking for signs of embryo implantation. Doctors believe that in most cases they are far-fetched. The sensations may be the following:

• minor nagging pain in the lower abdomen and lower back;
• temperature rise to 37.5 degrees;
• preservation basal temperature at 37 degrees and above;
• manifestations of toxicosis in the form of nausea or vomiting;
• increased drowsiness and weakness;
• increased irritability;
• distortion of taste;
• mood swings, unstable psycho-emotional state.

All symptoms of embryo attachment to the wall of the reproductive organ may indicate other conditions and are not reliable. Special attention specialists and women are attracted to implantation bleeding after IVF. It manifests itself in the form of slight bloody pink or beige discharge and lasts no more than 2-3 days. Implantation bleeding occurs due to damage to small vessels during the implantation of the embryo into the mucous membrane. If it happened, then we can roughly guess the time when the embryo attached to the uterus. After a few days, a blood test will show pregnancy.

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Late implantation after IVF

If the transferred embryo was implanted into the mucosa no later than a week from the moment of ovulation (cell puncture), then they speak of early attachment. There is also the concept of late implantation, when cells penetrate the endometrium on the 10th day. The reasons for late embryo implantation during IVF are abnormalities in the development of the fetal egg or individual characteristics female body. This condition is not a pathology. On the contrary, with early attachment of the embryo, the endometrium may not yet be sufficiently prepared, and this is fraught with difficulties in the early stages of pregnancy.

The hCG hormone during late implantation is produced after direct attachment of the embryo. At a time when the embryo is in the uterine cavity, but is not in contact with it, this indicator does not grow. With late implantation, the pregnancy test may also not show positive result. Therefore, the patient will have to be patient. If there is a delay but the test is negative, you can always hope for the best.

Reasons for unsuccessful implantation after IVF

After a failed protocol, every patient worries: why doesn’t implantation of the embryo occur? It would seem that everything is thought out to the smallest detail: ovulation and the state of the endometrium are monitored by specialists, the ovaries give the answer, and the sperm perform their task. The reasons that implanted embryos do not implant may be:

• insufficient thickness of the functional layer of the uterus (for successful implantation it should be 13 mm);
• lack of nutrients necessary for cell division and maintaining the vital activity of the embryo;
• insufficient level of progesterone in the body;
• refusal to use hormonal support or low doses of drugs;
• endometrial pathologies (polyps, infectious and inflammatory diseases, hyperplasia or hypoplasia);
• pathologies of the myometrium (adenomyosis, fibroids, diffuse changes);
• genetic disorders of the embryo, defects that inhibit development.

One of the reasons for unsuccessful in vitro fertilization may be a thick protective membrane of the fertilized egg. Often this condition occurs in older patients or when performing a cryoprotocol that involves thawing cells. To solve this problem, preliminary hatching is carried out - removal of the pellucid zone.

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According to statistics, successful implantation during the first IVF protocol occurs in only 30-40 patients out of 100. If previously thawed embryos are implanted, the likelihood of a positive result is even reduced.