Successful attachment of the embryo. Reasons for the lack of attachment of the embryo to the uterus

It is simply amazing how many changes the female body undergoes and how many tests pass male spermatozoa to become possible conception child. Ovum in the ovary during long period ripens, which becomes possible only under certain conditions. Of the millions of sperm, only one will be able to fertilize her if he is good enough for this. The meeting of the cherished cells can occur only with good patency of the 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. It is possible to speak about the completed pregnancy not earlier than the implantation of the embryo occurs.

Embryo implantation in the uterine wall

As soon as the fastest sperm cell penetrates the wall of the egg, it will be covered with a specific membrane that does not penetrate 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 intensively divide, forming more and more cells. It moves up the fallopian tubes 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 fetal egg sheds its protective membrane, exposing the trophoblast, which helps to gain a foothold in the uterine wall and then participates in the formation of the placenta. If the membrane is too dense, then implantation may not take place. As a rule, only healthy, without genetic disorders the blastocyst manages to gain a foothold in the uterine membrane - natural selection acts. 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 fetal egg may be violations from female body or from the blastocyst cells:

too thick protective shell of the fetal egg;
genetic disorders in the development of the blastocyst;
inconsistencies in 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 fixing and further development of the fetal egg);
nutritional deficiency in the tissues of the uterus.

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

On what day after ovulation does the implantation of the embryo occur: terms

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

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

The entire process of the introduction 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 fetal egg “pulls out” a nest for itself, in which it “takes root” - the trophoblast of the egg will penetrate through the tissues of the uterus, taking root in it. As the “construction work” progresses, the blastocyst can arrange breaks for itself: the process of implementation either stops 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 crucial. If the fertilized egg manages to establish itself, 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 early stages development of pregnancy, he (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 behave with the utmost care 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 the symptoms of embryo implantation in any changes and even in their absence. Meanwhile, doctors confirm that indeed in the hours or days when a fertilized egg is introduced into the uterus, certain sensations may arise. It’s just that they should be evaluated truly objectively, and, of course, a woman who is expecting or suspecting pregnancy in the last cycle is more likely to notice such signs.

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

Implantation bleeding. It is the discharge of a very meager amount of blood from the vagina (literally no more than a few drops), which stains the whites in a reddish, beige or brownish color. "Bleeding" occurs due to damage small vessels in the process of implantation of the embryo into the uterine epithelium.
Drawing pains in the lower abdomen (or tingling). Some are weaker, unobtrusive, some are quite strong, tangible, but many women feel pain in the lower abdomen during the implantation period. Usually they are localized at the site of attachment of the egg.
An increase in temperature - both basal and body temperature. And during the entire first trimester, and even now, in the first days of pregnancy, the temperature can 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 a high degree of probability makes it possible to suspect the onset of pregnancy. It is during the period of implantation that BBT 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 breakdown, dizziness, apathy.
Mental instability. Mood and emotions quickly, suddenly and for no reason replace each other in opposite directions. Often a woman feels increased need in love and attention to himself, he begins to feel sorry for himself, whine, lose heart.

Implantation bleeding: discharge

We have already talked about implantation bleeding, but this feature should be considered in more detail. The fact is that already in the first weeks of pregnancy there may be a threat of its interruption. At the same time, against the background of pulling pains in the lower abdomen, bloody issues various shades of red. In addition, it can also smear and bleed due to genital infections or gynecological diseases.

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

Implantation bleeding, despite its name, has nothing to do with bleeding and does not look like it at all.

Embryo implantation for IVF

AT recent times More and more couples are turning to the services of reproductive specialists in order to become pregnant. In this regard, the question arises of how the implantation of the embryo occurs after IVF. Differences from pregnancy naturally in this regard, there are almost none: the whole process of the introduction of the fetal 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 in IVF may have some peculiarities. Due to the fact that conception took place outside the mother's body, planted in female uterus the embryo may need to adapt to new environmental conditions. For this reason, the introduction of embryos (and several of them are planted at once to increase efficiency) ends successfully in only about a third of all cases. If the implantation of the fetal egg after IVF still occurs, then more often it is late and lasts longer than usual. In addition, in order to minimize the risks of non-survival, the expectant mother should take care of:

Get more rest, get enough sleep at night.
Eliminate physical and nervous stress, do not lift weights.
Refrain from taking hot baths and showers, having sex.
Avoid overheating and hypothermia.
Eat well.
Take leisurely walks in the fresh air.
Eliminate the impact on the body of harmful factors (household and industrial chemicals, for example).
In season viral diseases do not visit crowded places.

In general, you need to take care of yourself 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 period, and only then does it begin active growth baby.

Especially for - Larisa Nezabudkina

Embryo implantation the process of its attachment to the uterus is called. In this case, the embryo "grows" into the uterine mucosa, which ensures its further development and the formation of a full-fledged fetus. To understand the mechanisms of embryo implantation, some knowledge of the anatomy of the female genital organs and the physiology of reproduction is necessary.

An embryo can only be formed by the fusion of a male germ cell ( sperm) with a female reproductive cell ( ovum). Each of these cells contains 23 chromosomes responsible for the transmission of genetic information. During fertilization, the chromosomes of male and female germ cells unite, resulting in the formation of one full-fledged cell ( zygote), which contains 23 pairs of chromosomes.

AT vivo this process takes place in the following way. During ovulation, a mature and ready-to-fertilize egg leaves the ovary and moves into the fallopian tube ( connects the uterine cavity to the ovaries), where it remains for about a day. If during the stay of the egg in the fallopian tube it is fertilized by a sperm cell, this will lead to the formation of a zygote.

The resulting zygote begins to divide, that is, first 2 cells are formed from it, then 3, 4, 5, and so on. This process takes several days, during which the number of cells in the developing embryo increases. Some of the resulting cells accumulate inside the embryo, and some outside ( around) them. The inner part is called the "embryoblast" ( of which the embryo will develop), while the cells surrounding the embryoblast are called "trophoblast". It is the trophoblast that is responsible for the process of embryo implantation and its nutrition throughout the entire period of intrauterine development.

In the process of division, the embryo embryo) gradually moves from the fallopian tube into the uterine cavity, after which the process of its implantation begins. The essence of this process is as follows. Initially, the embryo attaches to the surface of the uterine mucosa. In this case, peculiar villi are formed from trophoblast cells ( threads), which grow into the mucous membrane and begin to produce specific substances that destroy it. As a result of this, a kind of depression is formed in the mucous membrane of the uterus, into which the embryo is immersed. Subsequently, the mucosal defect closes, as a result of which the embryo is completely immersed in it. At the same time, trophoblast filaments continue to penetrate into the tissues of the uterus, receiving nutrients and oxygen directly from maternal blood. This ensures the process of further development of the embryo.

The timing of embryo implantation in the uterine mucosa ( endometrium) after ovulation and conception ( How many days does embryo implantation take?)

The process of zygote development and embryo implantation takes about 9 days.

As mentioned earlier, a mature female germ cell is released from the ovaries during ovulation. Then it moves into the fallopian tube, where it remains for about 24 hours. If during this time she is not fertilized, she dies and is excreted from the woman's body, followed by menstrual bleeding. If fertilization occurs, the resulting embryo will penetrate into the uterine cavity and implant in its mucous membrane ( endometrium).

Before embryo implantation occurs:

Fertilization of the egg- there is a maximum within 24 hours from the moment of ovulation ( ovulation itself takes place approximately 14 days after the first day of the last menstruation).
The transition of the embryo from the fallopian tube to the uterine cavity- observed on 3 - 5 days after fertilization.
Start of implantation- begins on the 6th - 7th day after fertilization.

Embryo implantation directly from the moment of its attachment to the uterine mucosa and until complete immersion in it) takes about 40 hours. Therefore, from the moment of ovulation and until the embryo is completely immersed in the uterine mucosa, about 8-9 days pass.

When is embryo implantation considered early or late?

Early implantation is referred to in cases where the embryo is completely immersed in the uterus before 7 days from the moment of ovulation. At the same time, implantation is considered late if the embryo penetrates the uterine mucosa 10 or more days after ovulation.

The reasons for the violation of the terms of implantation can be:

Individual characteristics of the female body. All the figures and terms given earlier are considered optimal, observed in most women. At the same time, absolutely normal embryo implantation can occur both on the 7th and 10th day from the moment of ovulation.
Fallopian tube anomalies. With partial obstruction of the fallopian tube, the fertilized egg can stay in it a little longer, as a result of which implantation can occur 1 to 2 days later.
Anomalies in the development of the embryo. If the process of cell division in the emerging zygote is slower than usual, this can also cause late implantation. At the same time, faster cell division can lead to implantation of the embryo on the 7th or even 6th day after ovulation.

Late implantation is usually not associated with any risks for the development of the fetus in the future. At the same time, with early implantation, the embryo can penetrate into the still unprepared, thin uterine mucosa. This can be accompanied by certain complications, up to termination of pregnancy for early dates.

How do pinopodiums affect embryo implantation?

Pinopodium are special structures that appear on endometrial cells ( mucous membrane of the uterus) and promote attachment and implantation of the embryo.

Under normal conditions ( during almost all menstrual cycle ) pinopodiums on endometrial cells are absent. They appear during the so-called “implantation window”, when the uterine mucosa is most prepared for the introduction of an embryo into it.

At the beginning of the menstrual cycle, the mucous membrane of the uterus is relatively thin, does not contain glands and other structures. As ovulation approaches, under the influence of female sex hormones ( estrogen) the mucous membrane thickens, a large amount of glandular tissue and so on. However, despite all these changes, the endometrium is still not ready for the "introduction" of the embryo. After ovulation, there is increased production of the hormone progesterone, which prepares the uterine lining for the upcoming implantation. It is believed that it is under the influence of this hormone that the so-called pinopodiums are formed - protrusions cell membranes mucosal cells. This facilitates the process of attachment of the embryo to the uterus and its introduction into the mucous membrane, that is, it makes the implantation process itself possible. Pinopodium data exist for a short period of time ( 1 – 2 days), after which they disappear. The chance of successful implantation of the embryo after this is greatly reduced.

It has been scientifically proven that pinopodia appear on the surface of the uterine mucosa on about 20-23 days of the menstrual cycle, that is, 6-9 days after ovulation. It is at this time that the developing embryo passes from the fallopian tube into the uterus and can be implanted into it.

How long can an embryo live without implantation?

The life of the embryo outside the uterine mucosa is limited and cannot exceed 2 weeks.

From the moment of fertilization until implantation in the uterus, the embryo receives nutrients and energy directly from the environment. This is provided by trophoblast cells ( outer shell of the embryo). They have the ability to process the decay products of the tissues of the uterine mucosa, which are constantly present in its cavity, using them to nourish and develop the embryo. However, this mechanism for obtaining energy is effective only as long as the nucleus remains relatively small ( that is, it consists of a small number of cells). In the future, as it grows and develops, the number of cells in it increases significantly, as a result of which it needs much more nutrients, oxygen and energy. The trophoblast cannot provide these needs on its own. Therefore, if the embryo is not implanted in the uterus within a maximum of 14 days from the moment of fertilization, it dies and is removed from the uterine cavity along with menstrual bleeding.

Artificial insemination and embryo implantation

artificial insemination ( in vitro fertilization, IVF) - this is medical procedure, during which the fusion of female and male germ cells is carried out not in the body of a woman, but outside it ( in artificial conditions using special tools and techniques).

IVF can happen through:

Fertilization in vitro. Several mature eggs are placed in a test tube, to which a certain amount of spermatozoa is added. Within a few hours, each of the eggs can be fertilized by one of the sperm.
Intracytoplasmic sperm injection. In this case, the sperm is injected directly into the egg using special equipment.

As a result of this procedure, several nuclei are formed ( embryos). Two or four of them are placed in the woman's uterus. If after that these embryos are implanted in the uterine mucosa, the woman will begin to develop a normal pregnancy.

To this procedure was successful and effective, doctors should take into account the peculiarities of the course of the woman's menstrual cycle, as well as the peculiarities of the development of the endometrium ( mucous membrane of the uterus).

It is recommended to start the procedure on the day of ovulation ( approximately 14 days after the first day of the last menstrual period). This is due to the fact that after direct fertilization, the embryo will have to continue to develop in a special incubator for several days ( outside the woman's body). Only when it reaches a certain stage of development can it be moved into the uterine cavity.

It is important to note that the transfer procedure ( also called "planting") embryos should be carried out at the moment when the uterine mucosa is most prepared for implantation. As mentioned earlier, this is observed 6 to 9 days after ovulation. If you transfer the embryos into the uterine cavity earlier or later, the likelihood of their implantation in the endometrium will be significantly reduced.

What day after the transfer ( replanting) Does the implantation of the embryo occur during IVF?

During IVF, quite mature embryos are usually transferred into the uterine cavity, which are already ready for implantation. After the transfer of such an embryo into the uterine cavity, it can begin to implant in its mucous membrane within a few hours, less often during the first day. At the same time, it is worth remembering that the implantation process itself is relatively slow, taking an average of about 40 hours. Therefore, after replanting the embryos and before the onset of pregnancy as such, at least 2 days must pass.

How thick should the endometrium be for embryo implantation?

For implantation to be successful, the thickness of the uterine mucosa during embryo transfer must be at least 7 mm and not more than 13 mm. This is one of important points affecting the success of the procedure as a whole.

The fact is that in the process of implantation of the embryo, the cells surrounding it ( trophoblast cells) destroy the mucous membrane of the uterus, as a result of which a kind of depression is formed in it, called the implantation fossa. The entire embryo should be immersed in this hole, which will ensure its normal development in the future. If the endometrium is too thin ( less than 7 mm), the probability increases that during the implantation process the embryo will not fully attach to it, that is, part of it will remain on the surface of the uterine mucosa. This will lead to a violation of the development of pregnancy in the future or even cause it to be interrupted. At the same time, if the embryo is immersed too deeply, the trophoblast filaments can reach the muscular layer of the uterus and grow into it, which will later cause bleeding.

It has also been proven that the probability of successful implantation is significantly reduced in cases where the thickness of the uterine mucosa at the time of embryo transfer exceeds 14–16 mm, however, the development mechanism this phenomenon not definitively established.

What is the difference between implantation when transferring 3-day and 5-day embryos in IVF?

With IVF ( ) into the uterus, women can transfer embryos that have previously developed under artificial conditions for three days ( three-day) or five days ( five-day) since fertilization. The probability of normal implantation and the success of the procedure as a whole largely depend on the duration of the development of the embryo outside the woman's body.

It should be noted right away that the choice of the transfer time is determined individually in each specific case and depends on many factors. To better understand this, you need to know how the embryo develops after the procedure. in vitro fertilization (ECO).

As mentioned earlier, the most common IVF method is in vitro mixing of female and male germ cells. After a few hours, the eggs are collected and transferred to special culture media that are placed in incubators. Whether they were fertilized is still unknown.

If the egg has been fertilized, on the second day it turns into a zygote ( future embryo) and starts to divide. As a result of this division, by the third day of development, the embryo consists of several cells and has its own genetic material. Further ( for 4 - 5 days) the number of cells also increases, and the embryo itself becomes the most prepared for implantation in the uterine mucosa.

It has been scientifically proven that for successful implantation, it is best to use three-day-old embryos ( the success rate is about 40%) or five day old embryos ( success rate is about 50%). younger ( two-day) embryos do not yet have their own genetic material, and therefore the likelihood of their further development is reduced. At the same time, with a longer ( more than 5 days) the stay of embryos outside the body of a woman increases the likelihood of their death.

The choice of one method or another is influenced by:

The number of fertilized eggs. If, after crossing male and female germ cells, only a few eggs were fertilized, it is recommended to transplant three-day embryos. The fact is that being outside the female body can adversely affect the viability of the embryos, and therefore the likelihood of their death increases. Therefore, the sooner they are transferred into the uterine cavity, the higher the chances of success of the procedure.
viability of fertilized eggs. If many eggs were fertilized during the crossing, but most of them died during the first 2 days in the incubator, it is also recommended to resort to the implantation of three-day embryos. If, by the third day after fertilization, the number of developing embryos is large enough, it is recommended to wait another 2 days and perform a five-day embryo transfer. In this case, the chance for successful development of pregnancy will increase, since a five-day embryo is considered more viable, and the implantation process itself will be as similar in time as possible to that during natural fertilization ( that is, it will take place approximately 6-7 days after ovulation).
Failed IVF attempts in the past. If, during previous attempts, all fertilized eggs died by 4-5 days of cultivation in an incubator, the doctor may resort to transferring three-day or even two-day embryos. In some cases, this allows you to achieve pregnancy.

It is worth noting that implantation with the transfer of five-day embryos occurs faster than with the transfer of three-day ones. The fact is that after fertilization of the egg ( when the first sperm enters her) a rather dense “fertilization shell” is formed around it. It prevents other sperm from entering and also protects the embryo during the next few days of development ( until implantation begins). Under normal conditions, the destruction of this membrane occurs after the embryo exits the fallopian tube into the uterine cavity, that is, 4-5 days after fertilization.

When a three-day embryo is implanted, it continues to develop in the uterine cavity during the day, while not attaching to its wall ( attachment is hindered by the same fertilization shell). After about a day, the fertilization membrane is destroyed, after which the embryo begins to implant in the uterine mucosa ( The whole process takes about 2 more days.). Therefore, from the moment of transfer of a three-day embryo to its complete implantation, about 3-4 days can pass.

If a five-day period is transferred into the uterine cavity ( more mature) the embryo, its fertilization membrane can be destroyed almost immediately ( during few hours), as a result of which, after 2 days, the process of embryo implantation can be completed.

Embryo implantation after cryotransfer in natural cycle

The essence of the method lies in the fact that pre-selected and frozen embryos are thawed, after which they are introduced into the uterine cavity in strictly certain time menstrual cycle ( for 20 - 23 days), when its mucous membrane is maximally prepared for implantation.

The selection of embryos for freezing is carried out at the stage of their development in a special incubator. As a rule, this is done during the first IVF procedure ( ), and some of the embryos are transferred into the uterine cavity, and some are frozen. In this case, both three-day and five-day embryos can be frozen. If the first embryo transfer procedure did not give any results ( that is, if they were not implanted in the uterus, and pregnancy did not occur), during the next cycle, the procedure can be repeated, while frozen embryos can be used ( which are preliminarily thawed before being introduced into the uterine cavity). If, after the transfer of a viable embryo, it is implanted in the uterine mucosa, then the pregnancy will proceed as usual.

The advantages of implantation of thawed embryos include:

No need to re-stimulate ovulation. Before the usual IVF procedure ( in vitro fertilization) a woman is prescribed special hormonal preparations, which leads to the maturation of several follicles in the ovaries at once ( that is, by the time of ovulation, not one, but several eggs mature at once). When using the method of cryoembryo transfer, the need for this disappears. The doctor simply determines the moment of ovulation, after which he calculates the time during which the thawed embryos should be transferred to the uterus ( usually 6-9 days after ovulation).
Optimal preparation of the endometrium ( mucous membrane of the uterus) to implantation. Against the background of ovarian hyperstimulation ( during which the simultaneous development of several eggs at once is stimulated) there is a significant violation hormonal background women. This can lead to abnormal and incomplete development of the uterine mucosa, as a result of which implantation may not take place. Before transplantation of thawed embryos, hyperstimulation is not carried out, as a result of which the uterine mucosa is more prepared for implantation of an embryo into it.
No need to re-obtain male germ cells. Since already fertilized eggs are frozen, it is not necessary to re-receive the seminal fluid of the husband or donor.

It is also worth noting that multiple studies have not revealed any abnormalities in the development and course of pregnancy when using thawed embryos.

Is it possible to implant two embryos on different days?

Implantation of two and/or more embryos on different days is possible, but only during the period of time when the uterine mucosa is prepared for this.

As mentioned earlier, the lining of the uterus is ready for implantation of the embryo from about 20 to 23 days of the menstrual cycle. If an embryo is implanted in her on one of these days, she functional state will not change immediately, that is, it will still remain ready for implantation. Therefore, if 1-2 days after that, another viable embryo enters the uterine cavity, it will also be able to implant in its mucous membrane and begin to develop.

This phenomenon can be observed during in vitro fertilization, when several embryos are placed in the uterine cavity at once. At the same time, they can be implanted on different days. However, if this happens, doctors usually remove all the "extra" embryos, leaving only one of them to develop ( or two, if the patient wishes and there are no medical contraindications).

Feelings, symptoms and signs of pregnancy with successful embryo implantation ( can you feel the implantation of the embryo?)

There are no reliable symptoms to determine the time of implantation with certainty. At the same time, many women report subjective feelings that, in their opinion, are associated with the implantation of the embryo. Indeed, after the introduction of the embryo into the uterine mucosa in the body of a woman, certain hormonal changes which can affect her general condition and well-being. As a result, some non-specific symptoms may appear, which together may indicate a possible implantation of the embryo.

The possible implantation of the embryo may indicate:

drawing pains in the lower abdomen ( mild or moderate);
mild increase in body temperature up to 37 - 37.5 degrees);
slight spotting from the vagina;
general weakness;
increased irritability;
decreased mood ( depression);
change in taste sensations a metallic taste in the mouth).

At the same time, it is worth noting that these symptoms can occur in a number of other conditions, as a result of which they cannot be considered reliable signs of successful embryo implantation.

Basal body temperature during and after embryo implantation

Basal body temperature may rise after embryo implantation, as a sign of a developing pregnancy.

Basal body temperature is the body temperature that should be measured in the morning ( after a good night's sleep) in the rectum, vagina, or mouth ( measurement should be taken at the same place and, if possible, at the same time). Under normal conditions, in the first phase of the menstrual cycle ( during maturation of the follicle and egg) the woman's body temperature drops slightly ( up to 36.3 - 36.4 degrees), which is due to hormonal changes occurring in the female body. Immediately before ovulation, the concentration of female sex hormones in a woman's body changes, as a result of which an even more pronounced, sharp decrease in temperature will be noted ( up to 36.2 degrees). After ovulation, at the site of a mature follicle, the so-called corpus luteum, which begins to produce the hormone progesterone. Under the action of this hormone, the uterine mucosa is prepared for the implantation of the embryo, and there is also a certain increase in body temperature during the following days of the menstrual cycle.

If the egg is fertilized and the embryo implants in the lining of the uterus, pregnancy begins to develop. At the same time, the concentration of progesterone ( hormone responsible for maintaining and maintaining pregnancy) in the blood of a woman is maintained on high level. This explains the moderate increase basal body temperature body ( up to 37 - 37.5 degrees), recorded in a woman during the first 16-18 weeks from the moment of implantation of the embryo.

At the same time, it is worth noting that an increase in body temperature associated with the production of progesterone will be observed during the second phase of the menstrual cycle ( about 15 to 28 days) even if pregnancy does not occur. Therefore, evaluate this symptom as a sign of successful implantation and pregnancy should not be earlier than 2 weeks after ovulation and only in conjunction with other data.

Is there going to be blood? brown, bloody discharge) after implantation of the embryo in the uterus?

After implantation of the embryo, slight bleeding from the vagina may be observed, which is associated with the implantation process itself. At the same time, it is worth noting that the absence of these secretions is also quite normal.

During implantation of the embryo, its outer shell ( trophoblast) grows with filiform processes into the tissue of the mucous membrane of the uterus. At the same time, the trophoblast secretes specific substances that destroy the tissue of the mucous membrane, as well as small blood vessels, glands, and so on located in it. This is necessary in order to create a kind of depression in the mucous membrane ( implantation fossa) where the embryo should be immersed. Since there is a violation of the integrity blood vessels, a small amount of blood ( usually no more than 1 - 2 ml) can be excreted from a woman's genital tract 6-8 days after ovulation or 1-3 days after embryo transfer during IVF ( in vitro fertilization). These discharges are observed once and quickly stop without causing the woman any serious concerns.

At the same time, it is worth remembering that profuse or repeated spotting may indicate the development of any complications ( improper attachment of the embryo, rupture of the cyst, and so on). If these symptoms are found, a woman should immediately consult a doctor.

An increase in the level of hCG during embryo implantation ( by days)

hCG ( human chorionic gonadotropin) is a hormone that is produced by cells of the placenta from the first days of pregnancy, allowing you to determine it ( pregnancy) availability at the earliest possible date.

The placenta is an organ that develops from embryonic tissue and provides communication developing fetus with the mother's body. It is through the placenta that the fetus receives oxygen, as well as all the nutrients and trace elements it needs in the process of intrauterine development.

The formation of the placenta begins with the formation of the so-called chorionic villi - structures consisting of embryonic tissue. By about 11-13 days of development, chorionic villi penetrate the tissue of the uterine mucosa and destroy its blood vessels, closely interacting with them. At the same time, oxygen and energy begin to pass from the mother's body through the chorionic villi into the fetus's body. Already at this stage of development, the cells that make up the chorionic villi begin to secrete chorionic gonadotropin into the mother's bloodstream, which can be determined using special tests.

As the embryo develops, the chorion turns into a placenta, the size of which increases up to 3 months of pregnancy. In accordance with this, the concentration of hCG, determined in the woman's blood, also increases. This may serve as one of reliable signs normal course pregnancy.

HCG levels in a woman's blood depending on the gestational age

*period of pregnancy ( since ovulation)*	The level of hCG in the blood
7 – 14 days(1 – 2 weeks)	25 – 156 mIU/ml ( milli international units per milliliter)
15 – 21 days(2 – 3 weeks)	101 - 4 870 mIU / ml
22–28 days(3 – 4 weeks)	1 110 - 31 500 mIU / ml
29 - 35 days(4 – 5 weeks)	2560 – 82300 mIU/ml
36 - 42 days(5 – 6 weeks)	23,100 - 151,000 mIU/ml
43 - 49 days(6 – 7 weeks)	27,300 - 233,000 mIU/ml
50 - 77 days(7 - 11 weeks)	20,900 - 291,000 mIU/ml
78 - 112 days(11 - 16 weeks)	6 140 - 103 000 mIU / ml
113 - 147 days(16 - 21 weeks)	4 720 - 80 100 mIU / ml
148 - 273 days(21 - 39 weeks)	2 700 – 78 100 mIU/ml

Breast after embryo implantation

A few days after the implantation of the embryo, a woman may feel a moderate bursting pain in her chest. This is due to the hormonal changes that occur in the female body after pregnancy. It is believed that hormones secreted by the placenta ( in particular human chorionic gonadotropin, as well as a little-studied placental lactogen or somatomammotropin) stimulate the development of the mammary glands and increase their size. This is what gives rise to pain that a woman may experience from the first weeks after conception.

Changes in the cervix after embryo implantation

The condition of the cervix and the cervical mucus in it changes after the implantation of the embryo and the onset of pregnancy. This is due to hormonal changes that occur in the female body.

After embryo implantation, you may experience:

Change in color of the cervix. Under normal conditions ( outside of pregnancy) the mucous membrane of the cervix has a pinkish tint. At the same time, after implantation of the embryo and the onset of pregnancy, new blood vessels are formed in the organ, which is accompanied by an increase in blood flow. This leads to the fact that the mucous membrane becomes slightly cyanotic.
Softening of the cervix. If the cervix was relatively dense before pregnancy, after implantation of the embryo it softens, becomes more plastic, which can be determined by the doctor during a gynecological examination of the patient.
Changing the position of the cervix. After the onset of pregnancy, the cervix drops below normal, which is associated with the development of the muscular layer of the uterus and an increase in its size.
Change in the consistency of cervical mucus. Under normal conditions, there is a mucous plug in the cervix, which is formed from cervical mucus. It protects the uterus from the penetration of infectious and other foreign agents. During the period of ovulation, under the influence of female sex hormones, the cervical mucus becomes more liquid, which facilitates the passage of spermatozoa through the cervical canal. At the same time, after ovulation, the hormone progesterone is released, which again makes the cervical mucus thicker. If the egg is fertilized and the embryo is implanted in the uterus ( i.e. pregnancy), the concentration of progesterone will be maintained at a relatively high level for a long time, and therefore the cervical mucus will also remain thick.

On what day after the implantation of the embryo, the test will show pregnancy?

Highly sensitive pregnancy tests can confirm its presence as early as 7 to 9 days after the fertilization of the egg.

The essence of all rapid pregnancy tests is that they determine the presence or absence of chorionic gonadotropin person ( hCG) in a woman's urine. As mentioned earlier, this substance is produced by special cells of the embryo ( chorionic villi) and enters the maternal circulation almost immediately after the process of embryo implantation ( that is, from the moment when the tissues of the embryo began to grow into the mucous membrane of the uterus and into its blood vessels). Once in the woman's bloodstream, hCG is excreted from her body along with urine, as a result of which it can be determined during special tests.

To date, there are many varieties of pregnancy tests, but their essence is the same - they contain a special substance that is sensitive to hCG. To conduct the test, a certain amount of urine should be applied to a specially designated area. If it contains enough high concentration hCG ( more than 10 mIU/ml), Chemical substance will change its color, as a result of which a second strip will appear on the test or the inscription “there is a pregnancy” ( in case of using electronic tests). If there is no hCG in the urine, the test will show negative result.

At the same time, it is worth noting that a negative result can be observed if the concentration of hCG in the urine of a woman is below the minimum detectable ( i.e. less than 10 mIU/ml). In doubtful cases, women are advised to repeat the test after 24 hours. If there really is a pregnancy, within a day the concentration of hCG will certainly increase to the required level, as a result of which the test will be positive.

Can ultrasound help detect embryo implantation?

ultrasound ( ultrasound procedure) – diagnostic method, which allows you to identify an embryo whose size reaches 2.5 - 3 millimeters, which corresponds to the 3rd week of development ( since fertilization).

The essence of the method lies in the fact that with the help of a special device, ultrasonic waves are sent into the body of a woman. Various tissues of the body reflect these waves with different intensity, which is registered by a special sensor and displayed on the monitor.

Under normal conditions ( outside of pregnancy) the mucous membrane of the uterus reflects ultrasonic waves evenly. Immediately after implantation of the embryo, its dimensions do not exceed 1.5 mm. This is too small to be determined by ultrasound. At the same time, after a few days, the embryo doubles in size, and therefore can be determined using highly sensitive equipment.

It should be noted that conventional ultrasound ( in which the sensor is installed on the front surface of the woman's abdomen) will allow you to detect pregnancy only from 4 to 5 weeks of development. This is due to the fact that the muscles of the anterior abdominal wall will create additional obstacles on the way ultrasonic waves. At the same time, with transvaginal ultrasound ( when an ultrasound probe is inserted into a woman's vagina) pregnancy can be detected already after 20-21 days from the moment of fertilization ( i.e. 10-12 days after implantation of the embryo in the uterine mucosa).

The procedure itself is considered absolutely safe and does not cause any harm to either the mother or the developing embryo.

Does D-dimer rise during embryo implantation?

During pregnancy, the concentration of D-dimers in the blood of a woman may gradually increase, which is associated with a change in her hemostasis system ( responsible for stopping bleeding).

Under normal conditions, the hemostasis system human body is in a kind of balance - the activity of the factors of the blood coagulation system is balanced by the activity of the factors of the anticoagulant system. As a result of this, the blood is maintained in a liquid state, however, at the same time, there is no pronounced bleeding due to injuries, bruises and other tissue damage.

During pregnancy, there is an increased activation of the blood coagulation system, resulting in an increased risk of blood clots - blood clots, which include fibrin protein. At the same time, the formation of a blood clot in the body of a pregnant woman triggers ( activates) an anticoagulant system that destroys this thrombus. In the process of destruction of a blood clot, the fibrin protein breaks up into smaller parts, which are called D-dimers. Consequently, the more fibrin is formed and decomposed in a woman's body, the greater will be the concentration of D-dimers in her blood.

The normal concentration of D-dimers in the blood healthy person must not exceed 500 nanograms in 1 milliliter ( ng/ml). At the same time, immediately after the onset of pregnancy, the concentration of D-dimers can gradually increase, which in some cases can cause complications.

Permissible levels of D-dimers depending on the duration of pregnancy

Increasing the concentration of D-dimers above acceptable level associated with an increased risk of thrombosis. At the same time, thrombi blood clots ) can form in blood vessels various bodies (especially in the veins lower extremities ), clogging them and disrupting the blood supply to tissues, thereby leading to the development of formidable complications.

Why does the implantation of the embryo cause pain in the lower abdomen and lower back ( aching, pulling, sharp, sharp)?

Moderate pain in the lower abdomen or pain in the lumbar region that occurs during the first few days after implantation can be observed in most women, which is absolutely normal. The fact is that in the process of implantation, the embryo destroys the tissue of the mucous membrane and penetrates into it, which may be accompanied by light, tingling or pulling pains in the lower abdomen. At the same time, pulling pains can radiate to lumbar region. Usually the pain syndrome does not reach a high degree of severity and disappears on its own after a few days.

At the same time, it is worth noting that pain after embryo implantation may indicate the presence of formidable pathological processes requiring urgent medical intervention.

Pain during implantation may be due to:

Inflammatory process in the uterine cavity. In this case, the patient will complain of severe, cutting pains that may occur paroxysmal or persist permanently.
Spasms of the muscles of the uterus. Spasms ( long, strong muscle contractions) are accompanied by metabolic disorders in tissues, which is manifested by sharp, paroxysmal, aching pains in the lower abdomen, occurring at regular intervals. In this case, the probability of successful implantation of the embryo is significantly reduced.
Violation of the integrity of the uterus. If the embryo is implanted not in the uterine mucosa, but in another part of the organ ( for example, into the fallopian tube or into the abdominal cavity), in the process of growth, it can damage neighboring tissues, thereby causing bleeding. At the same time, the patient will feel a sharp cutting pain in the lower abdomen, after which she may experience moderate or severe bleeding from the vagina.

Nausea, diarrhea ( diarrhea) and bloating during embryo implantation

Certain digestive disorders ( nausea, occasional vomiting, occasionally diarrhea) can be observed during the implantation of the embryo in the uterine mucosa. It is connected with hormonal changes the female body, as well as with the influence of the hormonal background on the central nervous system. The duration and severity of these phenomena can vary widely ( individually for each woman and during each pregnancy).

At the same time, it is worth noting that the listed symptoms may indicate food poisoning - a pathology that poses a danger to the health of the expectant mother and to the upcoming pregnancy. That is why it is extremely important to identify signs of poisoning in time and seek help from a specialist.

On the food poisoning may indicate:

repeated vomiting;
plentiful ( profuse) diarrhea;
marked increase in body temperature over 38 degrees);
severe headaches ( associated with toxicity);
the onset of nausea, vomiting, and diarrhea within a few hours after ingestion ( especially meat, poorly processed foods).

Signs of failed embryo implantation

If the embryo formed during conception is not implanted in the uterine mucosa within 10 to 14 days, it dies. In this case, certain changes occur in the mucous membrane, which make it possible to confirm unsuccessful implantation.

An unsuccessful embryo implantation can be indicated by:

Absence of the above signs of embryo implantation within 2 weeks from the moment of ovulation.
Negative pregnancy tests ( performed on days 10 and 14 after ovulation).
Heavy bleeding after ovulation is a sign of complications in which the normal development of the embryo is impossible).
Isolation of the embryo during bleeding ( in some cases it can be seen with the naked eye).
The appearance of menstrual bleeding 14 days after ovulation ( occurs only if pregnancy has not occurred).
Absence characteristic changes cervix and cervical mucus.
Lack of human chorionic gonadotropin ( hCG) in a woman's blood 10 to 14 days after ovulation.
The absence of characteristic changes in basal temperature ( if pregnancy has not occurred, after about 12 to 14 days initially fever body will again begin to decrease, while during the onset of pregnancy, it would remain elevated).

Why is the embryo not implanted?

If after many attempts to get pregnant and fails, the cause of infertility may be unsuccessful embryo implantation. This may be due to both pathologies of the female body, and violations of the embryo itself or its implantation technique ( with IVF - in vitro fertilization).

The likelihood of unsuccessful embryo implantation can be affected by:

Women's hormonal disorders. For normal development endometrium ( mucous membrane of the uterus) and preparing it for implantation requires certain concentrations of female sex hormones ( estrogen), as well as progesterone ( pregnancy hormone). Moreover, an increase in the concentration of progesterone in the second phase of the menstrual cycle is necessary for normal process implantation of the embryo, and in the event of pregnancy - to maintain it. Violation of the production of any of these hormones will make implantation impossible.

Violations of the immune system of women. In some diseases of the immune system ( which is normally designed to protect the body from foreign bacteria, viruses and other similar agents) its cells may begin to perceive the tissues of the embryo as "alien", as a result of which they will destroy it. Implantation or the development of pregnancy in this case will be impossible.
Lifespan of embryos transferred during IVF. As mentioned earlier, during in vitro fertilization, five-day, three-day or even two-day embryos can be transferred into the uterine cavity. It has been scientifically proven that the longer the embryo has developed outside the woman's body, the higher the likelihood of its successful implantation. At the same time, the probability of implantation of two-day-old embryos is considered to be the lowest.
Time of embryo transfer in IVF. As mentioned earlier, there is a narrow time corridor when the uterine mucosa can accept an embryo implanted in it ( 20 to 23 days of the menstrual cycle). If the embryo is transferred earlier or later than the specified period, the probability of successful implantation will be significantly reduced.
Anomalies in the formation/development of the embryo. If the process of fusion of male and female germ cells did not occur correctly, the resulting embryo may be defective, as a result of which it will not be able to implant in the uterine mucosa and will die. Moreover, various genetic abnormalities in developing embryo can occur both during the implantation itself and during the first days after it. In this case, the embryo may also be unviable, as a result of which it will die, and the pregnancy will be terminated.
Developmental disorders of the endometrium ( mucous membrane of the uterus). If on preparatory stage the uterine mucosa has not reached the required thickness ( over 7 mm), the probability of successful implantation of the embryo into it is significantly reduced.
benign tumors uterus. benign tumors muscle tissue uterus can deform its surface, thereby preventing the attachment and implantation of the embryo. The same can be observed with pathological growth of the endometrium ( mucous membrane of the uterus).

Can a cold and cough interfere with embryo implantation?

A mild cold will not affect the process of implantation of the embryo into the uterine mucosa. At the same time, severe viral infections or bacterial pneumonia ( pneumonia) can significantly disrupt the condition of a woman, which will affect the ability of the endometrium to accept the implanted embryo. In this case, implantation may not occur at all.

It is also worth noting that a strong cough can disrupt the implantation process. The fact is that during a cough, pressure rises in the chest and in abdominal cavity, which leads to increased pressure in the uterus. This can provoke the “pushing out” of the embryo that has not yet attached from the uterine cavity, as a result of which implantation will not occur. At the same time, it should be noted that the practical importance of this mechanism of unsuccessful implantation remains in doubt.

Can I have sex during embryo implantation?

The opinions of experts on this issue differ. Some scientists believe that in normal ( natural) the conditions of having sex during the implantation of the embryo do not affect the process of its penetration into the uterine mucosa. They argue this by the fact that many couples regularly have sex both during and after ovulation, which does not interfere with the development of a woman's pregnancy.

At the same time, other scientists argue that sexual intercourse can adversely affect the process of attaching the embryo to the uterine mucosa. It is assumed that contractions of the muscular layer of the uterus observed during intercourse can change the state of the endometrium ( mucous membrane), thereby reducing the likelihood of successful implantation of the embryo into it. Moreover, during intercourse, entering the uterine cavity seminal fluid can disrupt the state of the endometrium and the embryo, which will also negatively affect subsequent implantation.

Despite many years of research, it was not possible to reach a consensus on this issue. At the same time, it should be noted that when performing IVF ( in vitro fertilization) doctors forbid sex after embryo transfer into the uterine cavity. This is due to the fact that transferred embryos can be weakened ( especially in case of transfer of 3-day or 2-day embryos), as a result of which any, even the most insignificant external influence can disrupt the process of their implantation and further development.

Is it possible to implant an embryo on the day of menstruation?

Embryo implantation on the day of menstruation ( during menstrual bleeding) is impossible, which is associated with certain changes in the uterine mucosa observed in this period.

Under normal conditions, the uterine mucosa consists of two layers - basal and functional. The structure of the basal layer remains relatively constant, while the structure of the functional layer changes depending on the day of the menstrual cycle. During the first days of the cycle functional layer begins to grow and develop, gradually thickening. Blood vessels, glands and other structures grow in it. As a result of such changes, by the time of ovulation, the functional layer becomes sufficiently developed to accept a fertilized egg in a few days.

If implantation of the embryo does not occur, the tissue of the functional layer of the endometrium separates from the basal layer. In this case, there is a rupture of the blood vessels that fed it, which is the direct cause of the onset of menstrual bleeding. Together with blood from the uterine cavity, torn fragments of the functional layer of the mucous membrane are released. Embryo implantation under such conditions is impossible in principle ( even if the embryo enters the uterine cavity, it simply has nowhere to implant).

Will there be periods after embryo implantation?

After successful implantation of the embryo, there will be no menstruation. The fact is that after the successful penetration of the embryo into the mucous membrane of the uterus, pregnancy begins to develop. At the same time, certain hormonal changes are observed in the mother's blood, which prevents the separation of the functional layer of the endometrium ( mucous membrane of the uterus), and also blocks contractile activity the muscular layer of the uterus, ensuring the further development of pregnancy.

If menstrual bleeding appears 14 days after ovulation, this will indicate unsuccessful implantation and the absence of pregnancy.

How to behave in order to increase the chances of successful embryo implantation?

To increase the likelihood of the embryo entering the uterine mucosa, a series of simple rules and recommendations.

The chances of successful embryo implantation increase:

In the absence of sexual intercourse after embryo transfer during IVF ( in vitro fertilization). As mentioned earlier, having sex can disrupt the process of attaching the embryo to the lining of the uterus.
With complete physical rest during the expected moment of implantation. If conception occurs naturally, a woman is forbidden to lift weights and perform any physical work within at least 10 days of ovulation ( until, theoretically, implantation of the embryo into the uterine mucosa is completed). With IVF, physical activity is also contraindicated for a woman for 8-9 days after embryo transfer.

When you receive enough protein food within 10 days of ovulation. A woman is advised to eat foods that contain a large amount of protein ( cottage cheese, eggs, meat, fish, beans and so on). This contributes to the implantation of the embryo and its development in the uterine mucosa. It is important to note that switching exclusively to protein food should not, however, its share in daily diet should be increased.
When calculating the day of ovulation and the “implantation window”. If a couple is planning a pregnancy, a woman is advised to calculate the ovulation period, when a mature egg leaves the ovary and moves into the fallopian tube. Since the egg remains in the tube for only 24 hours, sexual contact must take place during this period of time. At the same time, if conception occurs during IVF, embryo transfer should be performed taking into account the time of the so-called “implantation window” ( 6-9 days after ovulation), when the mucous membrane of the uterus is maximally prepared for the penetration of embryos into it.
When replanting five-day embryos during IVF ( in vitro fertilization). It is believed that five-day-old embryos are the most viable, since their genetic apparatus has already been formed. At the same time, during the transplantation of two-day and three-day embryos, their genetic apparatus is formed in the uterine cavity. If any abnormalities occur, the embryo will die.
In the absence of inflammatory processes in the uterus. Inflammation of the uterine mucosa can reduce the chance of successful implantation, so any infections or other infections should be treated before pregnancy is planned. inflammatory diseases genitals.

Before use, you should consult with a specialist.

Collapse

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

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 outgrowths-thorns. It is in this place that the fetal egg, and then the fetus, will remain and develop throughout the pregnancy, and it is there that the placenta will form, initial stages the presence of which are already visible at the stage of attachment.

Feelings during implantation

What sensations arise during the implantation of the embryo in the uterus? It is important to understand that when a fetal egg is attached, which occurs about a week after the fertilization of the egg or after the transfer of embryos into the uterine cavity (during in vitro fertilization), the endometrium is injured by the spikes of the fetal egg. Although such an injury is minor, it can nevertheless be accompanied by certain symptoms. But the symptomatology, whatever it may be, occurs only in 30% of cases, in 70% of pregnancies, the woman does not notice the passage of this stage:

Attachment has the following external features:

Bloody discharge, very slight in the norm, for only a few hours or even at once;
An admixture of blood in normal vaginal discharge.

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

Weak pain in the lower abdomen (sometimes it can increase to moderate intensity), lasts 2-3 days;
Feeling of heaviness in the lower abdomen;
Some tingling is felt in the mammary glands;
An unpleasant metallic taste may be present in the mouth for about one day;
mild nausea or subjective and very slight signs of food poisoning;
An increase in body temperature to about 37.5 degrees without worsening well-being.

From the side of general well-being, symptoms such as fatigue, general weakness and deterioration of health.

Feelings after implantation

Implantation itself takes approximately less than one day. But several unpleasant symptoms persist after it, for example, spotting may be present for another one to two hours. Also, for a couple of days, heaviness and pain in the lower abdomen may continue to be present. A more or less constant character is taken by tingling in the chest. Nausea appears in its form, which is characteristic of pregnancy.

The transfer of embryos into the uterus during in vitro fertilization is often 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 be pain and bleeding, which persist even 10-12 days after ovulation, that is, for several days after implantation of the embryo into the uterus. In addition, a strong increase in temperature serves as an alarm signal, as this may indicate that the symptoms are caused by an inflammatory process, and not by the attachment of a fetal egg.

The absence of any sensation both during attachment and after it has taken place is not considered to be any negative symptom. it normal condition organism.

IVF transplant

Conclusion

The presence of any sensations during implantation should not be considered a reliable indicator of the presence or absence of pregnancy. Attachment of the embryo may or may not be accompanied by any symptoms. Simply put, if pain a week after ovulation was not, this does not mean that the woman is not pregnant. Just as their presence can be caused different reasons including pathological ones.

You should be careful about signs that deviate from the norm. Because they can be both a sign of abnormal implantation at conception, and a sign of some kind of pathology in the absence of conception. If symptoms appear that are clearly not in line with the norm, in any case, you should immediately consult a doctor, regardless of whether the patient planned pregnancy or not.

Striking is the fact what changes occur in the body of a woman and how much sperm must pass in order to conceive a child. First, the egg needs to mature, then it is fertilized by the sperm. However, it should be good enough. When the cells fuse, they travel to the uterus. Pregnancy occurs when the embryo is fixed in the epithelium, the first symptoms of embryo implantation in the uterus occur.

Implantation process

Doctors say that it is very important to know about the signs of engraftment of a fertilized egg. After all, this is the process of developing a new life, which is considered milestone pregnancy. When an egg is fertilized, an embryo is formed. It is inserted into the uterus. There are villi on the embryo, when it penetrates the uterus, then after these villi damage it. As a result, blood is released. Then the embryo is strengthened on the uterine wall and develops.

How long does it take for an embryo to implant in the uterus? It mostly happens in the second week after conception. In the body where the implant will be carried out, edema occurs, fluid accumulates there. A defect appears in the mucosa, therefore small discharge blood.

In addition, the woman feels unwell in general condition, the temperature rises. If we talk about the symptoms of implantation of the embryo after IVF, then they are almost the same.

Just future mommy strongly expects their occurrence, as they guarantee the success of fertilization. Also, in the presence of such signs, it becomes clear that rejection does not occur, so the pregnancy will not be interrupted.

The female body perceives a fertilized egg as a foreign substance. This is due to the fact that this object has paternal genes. Sometimes the body wants to reject it. Many women do not feel any special changes during implantation. After all, changes in the hormonal sphere are not particularly manifested, everything goes mostly painlessly.

Signs of implementation

The first signs of embryo implantation indicate elevated level HCG, as well as unusual sensations for yourself. Not everyone knows that the main indicators of implantation in the uterine cavity are divided into types.

Subjective signs:

discomfort in the abdomen;
slight malaise, want to sleep, irritability is observed;
itching in the uterine cavity;
it looks like menstruation is about to start.

In addition, the most common indicator is the taste of metal in the mouth, slight nausea. When a woman begins to remember what she drank or ate, she does not think that the implantation of the embryo and its development are now taking place.

Objective indicators:

small bleeding;
a slight increase in temperature;
detection of the hormone chorionic gonadotropin. This is a guarantee of pregnancy.

It is worth noting that egg implantation may be late. The symptoms and quality of the embryo do not differ from other types of implantation. In addition, blood discharge does not always occur, the temperature rises. These are the first symptoms of fixing the embryo in the uterus.

The time during which the fertilized egg is attached to the uterus is called the implantation period. There are times when everything happens without change until there is no external signs. Sometimes there is an implantation retraction, when the basal temperature drops for a short period of time before rising during implantation.

Thus, if a woman becomes pregnant, then she must take care of her health with special attention up to 20 weeks. By this period, the placenta is fully formed, then the baby is better protected. Implantation also lasts until this period. Naturally, not always from the first days future mom feels the first signs of attachment of the embryo, but some feel the changes, as well as describe them with confidence and in specific detail.

The initial stage in the development of the future fetus is considered to be its implantation (introduction) into the wall of the uterus. Without this process, its further growth and embryogenesis is impossible.

Fertilization is based on the formation of a zygote by the fusion of an egg and a sperm. A mature egg can only be fertilized at the time of ovulation, after it leaves the ovary and moves into the fallopian tube. The egg is there for some time (about 24 hours), during which it can connect with the sperm.

Further, the zygote formed from the germ cells begins to continuously divide (the number of cells increases). During active division, the embryo leaves the fallopian tube and moves towards the uterus, where it is further fixed.

Every woman planning her pregnancy is interested in when the implantation of the fetal egg occurs, and from what time it is necessary to behave more carefully and take care of your body.

In order to understand on what day the embryo enters the uterus, it is necessary to understand what precedes this process. The whole initial mechanism for the development of pregnancy is as follows:

the exit of a mature egg from the right or left ovary into the corresponding fallopian tube with the further presence of the cell there throughout the day;
fertilization of the egg by sperm within 24 hours;
migration of the embryonic egg directly to the place of attachment in the uterus by about 3-5 days after the formation of the zygote;
the beginning of the introduction of the embryo by 6-7 days after the fusion of the female and male germ cells.

The implant itself goes through the following stages:

attachment of the embryo to the uterine mucosa;
the formation of threads from the trophoblast (outer cells of the dividing zygote) and their penetration deep into the mucosa;
deeper destruction of the uterine wall by the villi of the chorion and the formation of the so-called implantation fossa, in which the embryo is located. Around this recess, one can note areas of hemorrhages formed as a result of active destruction of the mucous membrane by proteolytic enzymes, followed by the active introduction of chorionic villi into it;
closure of the formed defect (fossa) from all sides;
continued penetration of trophoblast filaments into the uterine cavity.

The whole process of implantation of the embryo lasts about 40 hours. Therefore, we can say that the implantation of the embryo occurs on the 8-9th day after ovulation. This indicator is considered average. The fixation parameter of a fertilized egg can vary from 6 to 12 days after the onset of ovulation. Some women have implantation a few days before the start of the expected new menstruation.

The duration of the process of implantation of the embryo into the uterine wall is influenced by several factors:

viability and general condition of the embryo;
hormonal background of a woman;
condition and functionality fallopian tubes, which jerkily help the egg pass through them.

Thus, the term of embryo implantation is an individual indicator for each woman.

When is implantation considered early or late?

Depending on the individual characteristics of the woman's body, early and late implantation can be distinguished.

Comparative characteristics of the two types of implantation is as follows:

So, implantation on the 14th day after ovulation is rightfully considered late as well as implantation on the 10th day after ovulation. Some features of the embryo, as well as the maternal organism, can affect the rate of its implantation into the uterine cavity. Excessively rapid cell division can cause early attachment. So, there were cases of embryo implantation on the 3rd day after ovulation.

Early implantation is considered more dangerous for the embryo, this is due to the fact that the embryo is attached to the still insufficiently mature and unprepared mucous membrane, which in the future can lead to spontaneous abortion.

implantation bleeding

One of the signs of the attachment of the embryo in the wall of the uterus is implantation bleeding. It occurs at a time when the embryo is fully fixed in the mucous membrane. Most often, such bleeding lasts from several hours to a couple of days. This phenomenon occurs as a result of active destruction of the vessels of the uterus by the villi of the chorion at the site of attachment of the embryo. The process itself is not pathological and should not frighten the expectant mother. Normal implantation bleeding must meet the following requirements:

have a pink or light brown hue. In no case be bright red or dark brown;
occur once or several times, but disturb the woman for no more than two days;
appear in small quantities in the form of inclusions or a few drops.

Physiological implantation bleeding may be accompanied by moderate pain syndrome pulling character in the lower abdomen. Pain is a consequence of spasm of the muscle fibers of the uterus.

In the event that the discharge has the above symptoms, do not worry, it is recommended to listen to your body and provide it with the most comfortable conditions.

Features of the attachment of the fetal egg during natural conception and during IVF

Placement in the uterus of fertilized eggs outside the body of a woman is carried out no earlier than 6-9 days after ovulation. It is during this period of time that the mucous membrane is most prepared for the introduction of the embryo into it. An earlier or, conversely, late replanting may not be successful.

The optimal thickness of the endometrium for the introduction of a fetal egg into it is considered to be 7-13 mm. With an indicator less than 7 mm, the chances of engraftment fall. The same applies to the mucosa, the thickness of which exceeds 13 mm.

A distinctive feature of implantation during IVF is the fact that quite mature embryos are transferred into the uterine cavity, as prepared as possible for implantation into its wall. Such embryos can begin implantation within a few hours after their replanting, less often within a day. This is followed by the same duration of the process of implantation, as in natural fertilization, which takes about 40 hours.

Three- and five-day-old embryos are transferred to the uterus. Implantation of the second occurs much faster. This is due to the rate of destruction of the fertilization membrane. In three-day-old embryos, it collapses in about a day. Up to this point, it continues its development without attachment. The same shell in five-day-old embryos is destroyed in a few hours, which contributes to a faster introduction into the endometrium. In this case, implantation can be fully completed after 48 hours.

In the event that a fertilized egg takes root in a woman's body, the first symptoms occur somewhat later than with natural fertilization.

After attaching the fetal egg during IVF, the expectant mother must comply with certain conditions for the prevention of spontaneous termination of a long-awaited pregnancy:

limit physical activity;
normalize sleep and rest;
limit contact with infectious patients;
refuse to take a hot shower, bath, visit the bath and sauna;
temporarily limit sexual activity;
more often be in the fresh air, but do not overheat and do not overcool at the same time;
avoid stressful situations;
make your diet so that it is rich in vitamins and minerals.

If the embryo could not implant in the wall of the uterus, it will die within two weeks - this is the life span of the embryo.

The role of the endometrium in the process of implantation

The development of the endometrium and its physiological structural changes both phases of the menstrual cycle important aspects implantation. If this membrane of the uterus is damaged by inflammation or has any defects, the introduction of the embryo can be significantly difficult, and sometimes even impossible. If there are pathological foci in the mucous membrane, even successful implantation can result in spontaneous abortion, miscarriage or bleeding.

Before ovulation, the hormones estrogens soften the endometrium and increase the amount of glandular tissue in the uterus. During the so-called implantation window, pinopodia appear on the surface of the endometrium - structural units that contribute to the attachment of the embryo. The formation of these protrusions stimulates progesterone.

The implantation window, and, consequently, the existence of pinopodiums last no more than 2 days. Without them, the process of implantation of the fetal egg is impossible.

Methods for determining implantation

In addition to the subjective sensations that a woman may experience after implantation, there are a number of methods that most accurately indicate successful implantation. Among them:

increase in basal body temperature up to 37-37.5°C. The measurement should be taken in the same place (rectum, mouth, vagina) in the morning. However, an increase in basal temperature also occurs in the second phase of the menstrual cycle, and therefore this symptom should be evaluated in conjunction with the rest and not earlier than 14 days after ovulation;
an increase in the content of hCG in the blood of a woman depending on the duration of pregnancy: the longer the period, the higher the concentration of this hormone;
an increase in the concentration of D-dimer in the bloodstream;
cervical change:

the appearance of mild cyanosis of the mucous membrane due to the appearance of additional blood vessels;
increase in plasticity and softening;
some descent of the cervix due to an increase in the size of the muscle layer.

change in cervical mucus: the acquisition of a more viscous and thick consistency;
a positive pregnancy test result is also an obvious confirmation of successful implantation.

The main symptoms of embryo implantation

Knowing when the implantation of the fetal egg should approximately occur, a woman can focus on certain symptoms. So, we can highlight the main signs of attachment of the embryo to the uterus after ovulation.

Among them:

a small bloody patch in physiological secretions from the genital tract;
discomfort in the lower abdomen, which is characterized by moderate pain of a pulling or tingling nature;
a short-term decrease in basal temperature by 1-1.5 ° C shortly before general increase body temperature;
moderate soreness of the chest of a bursting character;
general weakness, dizziness, mood changes;
nausea, metallic taste in the mouth;
lack of menstruation on time.

Every woman experiences implantation differently. Someone notes not one, but several symptoms at once, while the well-being of other expectant mothers does not change at all.

Preparation for implantation

Every woman planning a pregnancy in the near future should pay Special attention pregravid preparation, which ensures firm implantation of the embryo and its further development. This preparation includes the following activities:

reception vitamin preparations: especially vitamin E and folic acid;
if we are talking about IVF - taking gestagnes, low molecular weight heparins, Aspirin, etc .;
normalization of sleep, rest and physical activity;
organization of a woman's mental comfort;
temporary cessation of sexual activity;
enrichment of the diet with only healthy foods and dishes.

Simple activities will help prepare the body for conception and the development of a new life.

When to take a pregnancy test

Highly sensitive tests that determine the presence of pregnancy can be done as early as 1-1.5 weeks after the alleged fertilization. In this case, there is no need to expect a delay in menstruation. The test shows a positive result when the concentration of hCG in the blood is more than 10mIU / ml.

Implantation at late ovulation will also be shown by the test. In this case, it also comes to the fore hCG level in the woman's bloodstream.

When to see a doctor

The main reason that should make a woman who is trying to get pregnant and mark all the important days for this process - ovulation, possible implantation, etc. - is the appearance heavy bleeding at a wrong time possible menstruation. The appearance of bright scarlet drops of blood in the discharge should not be ignored. These symptoms may indicate the onset uterine bleeding, which is a gynecological emergency. Often bleeding from the genital tract requires urgent surgical intervention.

If the bloody discharge that appeared during the alleged introduction of the embryo continues to disturb the woman 3-5 days after implantation and later, you should also immediately contact a specialist. Long-lasting brown, non-abundant discharge from the genital tract may indicate the progression of such pathological processes as:

cervical erosion;
polycystic ovaries;
endometrial hyperplasia;
neoplasms in the uterus (benign or malignant nature), etc.

These phenomena are treated in a planned manner. Depending on the severity of the disease and its etiopathogenesis, the doctor determines the direction of therapy: whether the patient needs medical conservative treatment or planned surgical intervention, supplemented by other methods of exposure (physio- and radiation therapy).

Thus, the timing of implantation is strictly individual for each woman. At the same time, great importance is given to general condition health, as well as directly to the health of the reproductive organs. For successful implantation and development of pregnancy, you must first get a consultation qualified specialist and in the future strictly follow all his instructions.