Signs and features of embryo implantation. Symptoms of embryo implantation: on what day after conception does the fertilized egg attach?

From the very moment the embryo is implanted, we can say with confidence that the pregnancy has taken place. It is from this day that the future human begins to grow and develop in the uterus. For the next nine months, this organ of the mother’s body will become a reliable and safe home for the baby. How does the implantation process occur, what changes does the mother’s reproductive system undergo, and what should a woman be prepared for?

Conception is an amazing process, a real miracle of nature! When you see a person in front of you, it’s hard to imagine that his life began at the moment of the merger of two tiny parent cells! But it is so.

Hypothetically an organism healthy woman reproductive age ready to conceive every month from the start of menstruation in adolescence. But in order for a mature egg to turn into an embryo, it must be fertilized. And it's not that simple!

She is ready for fertilization only a few hours on the day of ovulation. Ovulation occurs approximately on days 10-16 in monthly cycle. But even if unprotected sexual intercourse took place during this period, it is not a fact that fertilization will occur. Despite the fact that sperm “live” once in the female body for up to three days, they still have a very difficult path to reach the egg: first, through the destructive acidic environment of the vagina up to the cervix, then through the thick cervical mucus, then through the fallopian tubes against the flow of fluid.

But even after overcoming these obstacles, sperm must go through the main stage - penetrate through the two shells of the egg. Of the remaining number of the fastest and most “dexterous” sperm, perhaps only one will succeed in this - the rest will die, loosening the membranes.

It is very rare that two or three sperm fertilize an egg at once.

The following reasons may be an obstacle to conception:

• weak sperm activity;
• obstruction fallopian tubes;
• increased viscosity of cervical mucus;
• anomalies in the development of organs of the female reproductive system;
• immune factors;
• pathological processes reproductive system women, etc.

If the conditions for conception were favorable and it occurred, the fertilized egg (or zygote) begins to move towards the uterus, continuing to fragment along the way. At the same time, it does not increase in size, remaining at this stage 13 microns in size, but simply divides into smaller and smaller cells, forming a blastocyst on the fifth day of development - this is the name of a special stage of embryo development. By the end of its formation, the blastocyst consists of approximately two hundred cells.

Implantation process

Even before fertilization occurs, literally from the first day of the cycle, the processes of preparation for development began in the uterus possible pregnancy. The endometrium, which lines the inside of the uterus, begins to grow. If conception does not occur, endometrial cells will leave it with menstrual flow. But if pregnancy occurs, the endometrium will play an important role in attaching the embryo to the uterus: implantation is both physical and chemical contact between the endometrium and the blastocyst. Implantation is the process of attachment of an embryo to the inner wall of the uterus.

The outside of the blastocyst consists of special cells - trophoblast, and the internal cells are called embryoblast. The top of the blastocyst is covered by a membrane called hatching. By the time of implantation, the blastocyst resets hatching, and the trophoblast throws out processes, with the help of which it will be more convenient and reliable to plunge into the endometrial layer.

This is how the egg attaches to the uterus, and the endometrium, which nourishes it, continues to grow, surrounding the egg on all sides at the same time. The trophoblast begins to perform new feature- produce a special pregnancy hormone, hCG, and from now on, pregnancy can be confirmed by a blood test, and a little later it will appear, then pregnancy will be confirmed using a pharmacy test strip.

What can interfere

Quite often, egg implantation is difficult. Among the common reasons:

• absence or disruption of the mechanism of adaptation of the maternal body’s immunity to pregnancy;
• the presence of antibodies to cells that play an important role in the development of pregnancy;
• genetic malfunctions of the embryo;
• insufficiency of the uterine endometrium, etc.

If the transport of the zygote through the fallopian tubes is disrupted, it is possible for the embryo to be fixed outside the uterus (in the tube, in the ovary, sometimes in abdominal cavity), and then we're talking about O outside intrauterine pregnancy, a pathological condition dangerous not only for reproductive health, but also for a woman’s life.

On what day does the egg attach to the wall of the uterus?

HCG gives the body a signal that pregnancy is occurring and hormonal changes begin. Because of this, the process of maturation of new eggs stops, and approximately on the 14th day after ovulation, non-pregnant women expect menstruation, but if the embryo is already developing in the uterus, menstruation does not come - this is one of the very first and reliable signs pregnancy.

Stages of preimplantation development of the human embryo from the first to the seventh day. After fertilization, cell division occurs. Around the fifth day, the blastocyst appears. It is a fluid-filled structure consisting of an inner cell mass (white arrow) and a trophoblast (gray arrow). On the seventh day, the embryo is ready for implantation into the wall of the uterus.

Gynecological and embryological studies do not always make it possible to accurately determine on what day after conception the implantation of the embryo occurs. In most cases, this occurs 7-8 days after fertilization. Since the moment of fertilization coincides or approximately coincides (with a difference of up to a day) with ovulation, we can say that after ovulation, implantation of the embryo occurs on days 7-9.

But sometimes deadlines can shift. If implantation occurred before the seventh day after conception, the term “early implantation” is used. If implantation of the embryo occurs after ovulation later than 10 days, then gynecologists use the concept of “late implantation.” In general, the timing of implantation does not affect further course pregnancy.

How many days does implantation last on average? The process takes from several hours to 2-3 days - this is an individual feature female body.

Signs and symptoms

Are there any signs by which one can suspect that embryonic implantation has occurred in the uterus? Many women note that no unusual sensations accompany this process.

However, specific symptoms may be present:

• implantation bleeding: minor bloody issues, which are sometimes mistaken for menstruation. Bleeding is short-lived and occurs as a result of injury blood vessels when the blastocyst penetrates the endometrium. Many people confuse discharge during embryo implantation with the onset of menstruation. The difference is that menstruation is heavy. Bleeding during egg implantation is very scanty, and sometimes there is none at all;
• pain: sometimes in the lower abdomen, often radiating to the lower back;
• change in readings (implantation retraction on the graph, when the temperature drops from 37 - 37.5 degrees to 36.7-36.9). However, this retraction may not happen;
• malaise, dizziness.

On what day will the test show two lines?

On what day after implantation the test will show positive result? Ideally, a home express method for diagnosing pregnancy should be carried out at least from the first day of missed menstruation. But modern ultra-sensitive tests make it possible to do this before the delay, already five to six days after the intended implantation.

However, much more reliable result laboratory analysis blood for hCG, because it is in the blood that the concentration of this hormone is higher than in the urine, especially in the early stages.

Security measures

The first trimester of pregnancy - the time from the moment of conception to 10-12 gestational weeks (or 12-14 obstetric weeks) - is a difficult stage; it is called the critical stage of pregnancy. At this time, not only implantation occurs, but also the laying of all internal organs and baby systems. Heavy physical exercise, stress, taking antibiotics, infections and even poor nutrition may negatively affect the well-being of the resulting pregnancy.

If there gynecological diseases associated with a possible threat of miscarriage, the doctor may prescribe special drugs that will help preserve it. For example, in case of progesterone deficiency in the second phase of the cycle, duphaston or is used.

It's worth protecting yourself from sharp changes temperature, avoid visiting the steam room and taking a hot bath.

During feasts, you should resist the temptation to drink a glass or two of wine. Positive emotions, positive attitude, good food, sufficient quantity fresh air, loving and understanding others - this is the affordable minimum that everyone has the right to afford future mom so that the embryo implantation process is successful and further pregnancy proceeds without pathologies.

When planning a baby, a woman tries to control and calculate every stage of the process. Therefore, she is interested in finding out on what day the embryo is implanted after productive sexual intercourse.

Ovulation and conception - the main points you need to know

Before clarifying on what day after ovulation embryo implantation occurs and the symptoms characteristic of it, let us recall the entire duration of the childbearing process for a woman:

• Formation of a fluid-filled vesicle on the ovary.
• The birth of a cell in it.
• Development and growth of cells and follicles.
• The maximum size of the vesicle is 22-24 mm, by which time the cell has matured.
• Cell rupture of the walls of the vesicle.
• The cell moves towards the uterus.
• In the genital tract, a meeting with sperm occurs (if the situation is favorable).
• The cell is fertilized.
• The fertilized egg is implanted into the wall of the uterus.
• On the ovary using corpus luteum wound healing occurs. It also produces a hormone that promotes conception, egg attachment and the course of pregnancy in general.

So, on what day after ovulation does implantation occur? ovum, depends on some factors. This includes the immediate time of ovulation, the speed of cell movement, and its viability. It is no secret that the ovulation process is so fleeting that it can be difficult to reliably identify it.

Methods for determining the day of ovulation

By studying on what day after ovulation the embryo is implanted, the forum identifies a large number of girls who determine the moment itself incorrectly. Therefore, let us recall the basic rules for identifying the stage of follicle rupture:

• Mathematical calculation: subtract 14 days from the cycle. The resulting amount is counted from last menstrual period. This method Suitable for girls with stable rhythms. It is worth considering the possibility of failure due to stress, illness, climate change. It is advisable to confirm in additional ways.
• Discharge. When the follicle reaches its maximum size, the structure of the mucus changes under the influence of hormones. It becomes transparent, viscous, sticky, and is characterized by excessive abundance. The discharge continues while the cell is in the tract and throughout its life (up to 2 days). It is easy to notice mucus, because until this moment there was a “dry” period when the secretions did not penetrate outside.
• Pain in the ovary area. The cell breaks through the membrane, which is a wound, and therefore causes aching discomfort. They are minor and easy to ignore. The ovaries work alternately, so the pain will be different every month. different sides. It is easy to calculate the implantation of the embryo, on what day after ovulation, if the date of this pain is recorded. Ovulation will last a day or a little more after it.
• Tests. Easy way home definition. The strip must be dipped in collected urine and evaluate color change. They begin to be carried out a couple of days before the expected ovulation (according to calculations) and until the shade appears as bright as possible. This indicates the day before or directly the rupture of the follicle.

Ovulation with an irregular cycle

Calculating on what day after ovulation the embryo is implanted can be difficult for girls with irregular processes. For them, even identifying this day itself is problematic. Moreover, many couples try not to miss any possible moment and carry out acts for several days in a row approximately at the equator of the cycle. To identify it in more detail, you can consult an ultrasound. This is the most exact way and the doctor will name a specific date for the release of the cell, observing the growth trends of the vesicle.

When to expect implantation

If the acts were carried out in a timely manner and implantation of the embryo is expected, on what day after conception this is possible is of concern to many. And I would like to learn even more about the very first signs so that it can be identified reliably and earlier than you can try a test or get tested.

By contacting doctors and specialists, we get an answer on what day after ovulation the fetus is implanted into the uterus - on average 6-8 days. It is always considered normal to have a week after fertilization. It is believed that this is how long it takes for the egg to reach the uterus. But since, in everyone, cell movement and other processes occur with at different speeds, then there is a deviation of 1-2 days here too. The 10th day is already commonly called late implantation of the embryo, but on what day it happened can only be reliably found out from a doctor by visiting him at this moment.

Methods for determining implantation

After attachment, it is already possible to determine pregnancy using other diagnostic methods, despite the fact that doctors recommend waiting 14 days after conception before contacting them. These include:

• Blood analysis. At this time, a gradual increase in hCG begins, which is easily detected when donating blood several times.
• Tests. The concentration of hCG in urine is not yet high, so it is worth waiting a little longer.
• Inspection. Already when the fetus reaches 2 mm, it becomes visible when examined by a gynecologist.

If embryo implantation is expected during IVF, on what day the examination is scheduled, the doctor will tell you individually. It all depends on the characteristics of the patient’s processes. If you need to clearly know when embryo implantation is diagnosed, on what day after transfer, the parameter most often taken is the 10th day.

Main signs of implantation

Knowing what day after ovulation the egg implantation occurs, a woman can study the accompanying symptoms in order to independently diagnose the result. The most obvious sign is found in the form of a drop of blood in the discharge. This is normal, since the embryo breaks the capillaries in the lining of the uterus when it penetrates the endometrium, due to which a drop of blood can be released into the cavity. She's coming out naturally and is found on underwear. It's normal if it meets the following characteristics:

• It is found in the form of inclusions;
• Has a light or dark, but brown tint (not bloody);
• It is observed once or several times, but disappears after 1-2 days.

When is the best time to see a doctor?

If on this calculated date, on what day the embryo is implanted, real bleeding begins or scarlet drops are observed in large quantities, need to be accepted Urgent measures starting with a visit to the doctor. This may be a symptom of a serious disorder that even threatens the girl’s life.

If the bleeding is scanty and corresponds to the characteristics of embryo implantation, then on what day after conception it continues is worth noting in detail. If they don’t stop after a couple of days, the reasons may be very serious:

• Pathology of the cervix (erosion);
• Endometrial hyperplasia;
• Formations in the uterine cavity, incl. poor quality (cancer).

So, on what day after ovulation does fetal implantation occur, we have clarified. Therefore, it is worth taking a closer look at the discharge at this time. But they are not observed in everyone and sometimes are absent altogether. Therefore, you should not rely on them. It's better to wait another week and check if your period comes. This will be a more objective sign, after which you can carry out laboratory or other methods to check your condition.

Knowing what embryo implantation is, what day to expect it and how to confirm it, the girl has the opportunity to learn about the birth of a new life long before tests or tests reveal it. However, this may not be the case for everyone. Don’t forget to listen to your feelings, but don’t “overdo it” so as not to cause false pregnancy, when both the delay and characteristic features as morning sickness caused by psychological mood girls. You just have to stay calm and everything will come in due time.

Fertilization of the egg is one of the main, but not the last stages in a woman’s pregnancy. Much more significant is the stage of embryo implantation, i.e. its attachment in the uterine cavity.

Next, you are invited to familiarize yourself with basic information regarding the process of embryo fixation, the average time frame during which this process occurs after ovulation and at other stages of the cycle, possible deviations And additional features implantation of a fertilized egg during the procedure of artificial (in vitro) fertilization.

Basic information about the embryo implantation process

As is known, fertilization occurs at the moment of reaching the fastest and active sperm men female egg. Immediately after this, a membrane appears on the surface of the latter, preventing other sperm from penetrating inside. This “shell” remains on the surface of the fertilized cell until it reaches the uterine cavity.

In the process of “travelling” to its “destination”, the embryo continuously divides, during which an increasing number of cells are formed. The embryo moves up the fallopian tubes to the uterus - in this it is helped by the villi located on the fallopian tubes and the contractions of the latter: the embryo rolls around like a ball.

Upon arrival at the uterine epithelium, the fertilized egg loses its protective membrane, resulting in exposure of the trophoblast, through which the embryo attaches to the inner wall of the uterus. The trophoblast will retain its important function and in the future - it will take part in the formation of the placenta.

This is what the process of embryo implantation looks like ideally. However, in some cases there are various kinds negative factors, preventing the successful fixation of the embryo in the uterine cavity. For example, if the upper membrane is too thick, the embryo may not implant. This is one of the forms natural selection: only a genetically complete and healthy embryo has a chance of survival.

Problems with embryo implantation can also arise for other reasons, among which the following factors are most often noted:

• excessively thick outer membrane of the fertilized egg;
• dysfunction of the blastocyst, which is predominantly genetic in nature;
• inappropriate epithelial thickness internal cavity uterus;
• progesterone deficiency in the maternal body (under the influence of this hormone, among other things, conditions are created for the implantation of a fertilized egg and the subsequent development of the embryo);
• lack of nutrients directly in the tissues of the uterus.

The successful consolidation of the embryo is indicated by an increase in the concentration of hCG in the maternal body and a number of other signs, which will be discussed separately below. Now you are invited to familiarize yourself with information regarding the average time for embryo consolidation.

hCG at multiple pregnancy after IVF

Average embryo implantation time

On average, it takes about 1 week for a fertilized egg to “travel” to the uterus. In general, the duration of this process depends on the state of the embryo and its viability, the function of the fallopian tubes, hormonal structure in the maternal body and a number of other factors.

Based on average data medical research, the attachment of the fertilized egg to the uterine epithelium occurs in the period from 6 to 12 days after ovulation. This often happens a few days before the next menstruation.

Directly on the process of embryo implantation, i.e. implantation of the blastocyst into the inner wall of the uterus may take from a couple of hours to 2-3 days. Average term equals approximately 40 hours. During this time, the trophoblast of the fetal egg penetrates into the tissue of the inner surface of the uterus and takes root in the mother’s body. In this case, the process of implantation may either pause or proceed with greater activity, which is why signs of embryo implantation may also be episodic.

Implantation probability chart by days after fertilization

It is the implantation process that is most significant for developing embryo. If the embryo is successfully fixed, it is highly likely that it will be able to cope with other difficulties. If the embryo is sick and weak, the woman’s body may reject it even at this stage of pregnancy.

Depending on the individual characteristics female body, implantation of the fertilized egg can be late or early. Information regarding these points is given in the following table.

Table. Early and late dates implantation

For successful embryo implantation to occur, the following conditions must be met:

• thickness of the uterine mucosa – up to 1.3 cm;
• concentration nutrients- fine;
• progesterone content is sufficient to delay menstruation and ensure further full development of the fetus.

As a rule, most women have some major changes there is no feeling of well-being during implantation, but the possibility of their occurrence cannot be ruled out either. The main thing is to objectively assess changes in well-being and not try to mentally multiply them in anticipation of fertilization.

Among the most common signs of embryo fixation in the uterus, the following signals can be noted:

Above, in the list of signals of embryo consolidation, there was given such a sign as implantation bleeding, in most cases it manifests itself as a few drops of blood on the underwear. In some patients the situation may be more aggravated. So, if the patient experiences unpleasant pulling sensations in the lower abdomen, accompanied by bloody discharge, she definitely needs to see a doctor. A similar reaction of the body can be provoked by various types of gynecological and diseases and infections of the genitourinary tract.

Uninformed women often confuse this pathological condition with implantation bleeding, which is one of the normal variants. It is very important to be able to distinguish between them and promptly respond to such unfavorable changes in the state of the body.

So, when the embryo is implanted, the secretions have normal look, they just contain quite a bit of bloody inclusions. If your discharge differs from that described, consult a specialist immediately.

Features of embryo implantation during in vitro fertilization

Currently the only possibility become parents for everyone more couples is in vitro fertilization. The issue of embryo implantation after this procedure deserves special attention.

In general, there are no serious differences between the process under consideration and embryo attachment during natural pregnancy no: everything happens according to a similar scenario; after the procedure, a woman may experience some characteristic sensations etc.

But distinctive features during the implantation process artificial insemination everything is just like that. So, if conception was not carried out in the mother’s body, the implanted embryo may need some time to get used to its new conditions. It is because of this that it is not always (on average only 30-35% of cases) that women manage to get pregnant immediately after the in vitro fertilization procedure.

If a fertilized egg does implant, the first signs of this usually appear later than during natural conception. In order to reduce the likelihood of miscarriage, the expectant mother should take some precautions, namely:

• get enough sleep and rest in general;
• avoid excessive physical activity;
• eliminate stressful situations;
• temporarily (until permitted by a doctor) exclude sexual intercourse;
• don't take too much hot bath and shower;
• do not overcool or overheat;
• maintain a healthy and balanced diet;
• walk outside more often;
• minimize any harmful effects on the body;
• avoid visiting crowded places;
• do not contact sick people.

For the sake of their own safety and in order to minimize risks to the embryo, a woman after IVF is recommended to even refrain from managing vehicles and riding on public transport.

In general, doctors recommend following special measures precautions until the 20th week of pregnancy - by this period the placenta usually has time to fully form and the fetus becomes more protected than before. For example, with obstetric point vision, the implantation procedure takes place exactly up to the specified moment, after which the baby goes into active stage growth. But this does not mean that after the 20th week you can start treating yourself and the fetus lightly: precautions and doctor’s recommendations must be followed throughout the entire period.

Health to you and your baby!

Implantation of the fertilized egg into the uterine cavity usually occurs 3-4 days after sexual intercourse, and the process of implantation of the fertilized egg into the endometrium takes about two more days. From this period of time, the production and growth of the hCG hormone begins - the same one to which pregnancy tests with two strips react. But most exact result, literally already 9-10 days after intercourse, gives a blood test for hCG - errors in in this case it can not be.

Does implantation of the fertilized egg have other, earlier symptoms? They may be, but very indirect, that is, it is not at all a fact that they were caused specifically by conception, even if it occurred. Such signs include discharge during implantation of the fertilized egg, this may be scanty bloody discharge. But we must take into account that the nature of such discharge may be completely different - pathological. Namely, bleeding in the middle of the cycle can be caused by uterine tumors, endometriosis, and sometimes taking oral contraceptives. Please note that implantation bleeding It is never abundant, occurs in an extremely small number of expectant mothers, and almost always goes completely unnoticed. It is also possible to predict when attachment of the fertilized egg occurs - discharge is observed approximately 4-7 days after unprotected sexual intercourse.

Does the woman experience any other unusual sensations that can be perceived as signs of implantation of the fertilized egg into the uterine wall? Doctors answer that no, since everything happens literally on cellular level. Someone argues that at this crucial moment there arise nagging pain in the lower abdomen, but again, no one checked where these pains came from, because there can be a lot of reasons for their appearance - starting from flatulence and endometriosis, which is so common now... That is, there are no sensations during the implantation of the fertilized egg as such.

You can see the future baby in your uterus with your own eyes at the beginning of the first trimester of pregnancy. As we have already said, implantation of the fertilized egg after fertilization occurs in 4-7 days, and it grows unborn child to such sizes that can already be diagnosed on ultrasound in a couple of weeks. That is, with 1 week of delay in menstruation (5th week of pregnancy and 3rd week after implantation), the fertilized egg in the uterus reaches a size of several millimeters.

However, the very presence of this “education” in women’s reproductive organ does not always indicate a real, intrauterine pregnancy. The fact is that the fertilized egg may be empty... Embryo implantation(this is an everyday, not entirely correct expression) is visible at 5-7 weeks of pregnancy. Then the heartbeat is determined, by which they judge whether the unborn child is alive and developing.

It is also necessary to take into account this point - implantation of the fertilized egg occurs in the case late ovulation not for 16-20 days menstrual cycle, and later. This means that the embryo on an ultrasound machine, especially one that is not very good, may become visible a little later.

Thus, we can conclude that knowing the implantation of the fertilized egg on what day of the menstrual cycle occurred is quite important. However, there are modern and fairly simple medical techniques that allow one to obtain data on the development of pregnancy, which make it completely unnecessary to know the day of egg implantation.