Embryo implantation. Signs of embryo implantation

Implantation of the fertilized egg is the very beginning of the pregnancy period. It is practically not noticeable by the expectant mother, but, nevertheless, it is incredibly important for the development of the child. Its importance is confirmed by the fact that if the fertilized egg is not implanted, the child simply will not turn out.

In this article we will look at the symptoms of implantation of the fertilized egg, its timing and the sensations that a woman may experience. Many scientists argue that for the first time a woman feels something after implantation, however, discharge during implantation of the fertilized egg can say a lot.

Embryo implantation: on what day does attachment occur?

Typically, from fertilization of the egg to implantation takes from 7 to 10 days, if you count from ovulation. Before implantation into the wall of the uterus, the egg is protected by the zona pellucida. To attach to the wall, the membrane is shed, attached by the inner membrane, forming a trophoblast. The trophoblast villi are deeply immersed in the uterine wall for stronger attachment. Implantation into the uterine wall occurs in the absence of developmental defects. The IVF embryo is recognized and the pregnancy continues.

If the embryo has a genetic deformation, then at this stage it is rejected. Embryo implantation lasts an average of 40 hours, after which the development period begins. The implantation period as part of an IVF program lasts longer than usual. In some cases, when the zona pellucida is too thick, implantation may not take place. This phenomenon is most often observed in women after 40 years of age. For normal implantation, a certain level of progesterone in the blood is necessary, which stimulates the growth of the endometrium in the future. Implantation after IVF is often late.

When embryo implantation occurs and on what day after ovulation depends on the individual characteristics of each woman’s body.

Results of in vitro fertilization

Has the embryo been implanted

, checked by analyzing human chorionic gonadotropin - hCG. Testing is carried out approximately 2 weeks after the transfer. It is not advisable to do an analysis earlier, since hCG has not yet risen to a level where it can be accurately determined, so as not to make a mistake with the onset or non-occurrence of pregnancy.

Even after 2 weeks, some women may still have low hCG in their urine, so the test will show a negative result. At this time, you should not stop taking prescribed hormonal medications and other medications. A more accurate result will be obtained by laboratory testing of blood serum for hCG using the enzyme immunoassay method. Venous blood is taken on an empty stomach in the morning. The evening before, they have dinner no later than 19:00. You can conduct a rapid test for hCG, the results of which will be available in 1.5–2 hours. A typical hCG test will take 1-2 days. Gestation after IVF is confirmed using ultrasonography performed 3 weeks after embryo transfer, when the fertilized egg and its location are clearly visible. If late implantation does not take place and menstruation begins, then hCG is also tested after 1–2 days.

Normal HCG Levels During Pregnancy

Embryo implantation: timing

According to the time of attachment, implantation occurs:

1. late

(occurs 10 days after ovulation). If, after the specified time, signs of pregnancy do not appear, an ultrasound should be done to find out why there is no implantation;

2. early

(occurs in 6-7 days). Early implantation of an embryo into the uterus is quite rare.

Late is typical for embryos after IVF, since more time is needed to adapt to the internal environment of the body. Late implantation after IVF lasts about 2-3 days.

When late embryo implantation occurs after IVF, the level of human chorionic gonadotropin (hCG) does not increase immediately; this process is somewhat extended over time.

After implantation, the endometrium is transformed to form decidual cells, which participate in the formation of the placenta. The level of hCG in the blood increases.

Conditions required for embryo implantation:

• the thickness of the uterine mucosa should be no more than 13 mm;
• there must be a sufficient amount of nutrients in the walls of the uterus;
• Progesterone levels should be above normal. Progesterone delays menstruation and promotes embryo development.

Timing of implantation of the fertilized egg

When sex gametes are combined in vitro during IVF, a cell containing a chromosome set (diploid) is formed. The cell begins to divide, forming a blastomere (6–8 cells), then a morula appears (16–64 cells), then a blastocyst, which is implanted into the uterus.

Implantation of embryos occurs in one of three periods, which differ from each other in days after fertilization:

• Early - on the 6th day.
• Medium - on days 7–8, five-day implantation is carried out during IVF, which ends in success in 90% of cases.
• Late - on the 10th day.

The average time for implantation of embryos into the endometrium is 7–8 days after fertilization.

Stages of embryo implantation

How does this procedure feel?

Many patients participating in the IVF program ask doctors: “Is it possible to feel the implantation of an embryo?”, “What sensations should appear during embryo implantation?” Since this process lasts about 3 days, during this time some symptoms may appear:

• Brown discharge during implantation is normal. Discharge during embryo implantation is extremely scarce. If there are other discharges during implantation, especially prolonged and bloody ones, you should contact your doctor as an emergency.
• The pain during implantation is nagging in nature. The vast majority of women experience pain during embryo implantation. They can have a strong character or be unobtrusive. As a rule, the pain is localized at the site of attachment of the fertilized egg.
• Mild nausea.
• Metallic taste in the mouth.
• The temperature may be elevated to low-grade levels.
• Emotional lability and irritability.

Signs of embryo implantation in the uterus are quite varied and can manifest themselves individually in each woman.

Signs of implantation correspond to early signs of pregnancy.

Signs of embryo implantation after IVF are not observed in the vast majority of cases.

Answering the question “can you feel the implantation of an embryo?” you can answer in the affirmative, with the exception of late implantation as part of an in vitro fertilization program.

Why might an embryo fail to implant in the uterus?

Some women encounter a problem when fertilization itself occurs successfully, but the embryo cannot consolidate in the uterus and is brought out. Reasons why the embryo does not attach:

• Hormonal imbalance. For attachment to be successful, a sufficient amount of progesterone must be produced. It prepares the uterus to receive the baby and reduces the immune response to a foreign organism so that the mother’s body does not reject the embryo. When there is not enough progesterone, conditions for attachment are not created, and the embryo comes out. The cause may be insufficiency of the corpus luteum or its absence. This condition is treated with hormonal therapy, such as Utrozhestan or Duphaston.
• Endometrial changes. It happens that the embryo simply does not find a suitable place to implant in the uterus, because the surface of the endometrium is scarred. This condition of the endometrium can be a consequence of abortion with curettage, surgery on the uterus, inflammatory or infectious diseases. Late implantation at the os of the uterus can be a consequence of such pathologies.
• Tumor processes. New growths in the uterus - polyps, fibroids, fibroids - prevent the blastocyst from gaining a foothold in the cavity.
• Genetic abnormalities. Due to mutations in germ cells during fertilization, a non-viable zygote is formed. For example, two sperm get inside at the same time, or one of the gametes does not carry genetic information. Such an embryo does not develop, cannot attach, and miscarriage occurs before its implantation.

After the IVF procedure, doctors carefully monitor whether the embryos have taken root. At this stage of medical development, not all embryos take root, so patients undergo artificial insemination again.

Often, pre-implantation miscarriages are asymptomatic and the woman may not realize she was pregnant. Typically, such patients turn to gynecologists with the problem of infertility, not knowing that the problem is not conception, but the ability to implant. The doctor can help solve the problem by choosing the appropriate treatment method.

Artificial insemination and embryo implantation

The day of implantation is chosen taking into account the readiness of the expectant mother and the degree of maturity of the embryos. Embryos are cultured for 2-5 days before transfer. The most justified from the point of view of survival rate are implantation of 3-day embryos (survival rate about 40%) and implantation of 5-day embryos (about 50%). Embryologists follow the rule: embryo transfer and implantation is performed on day 3, if by that time there are already at least 5 embryos, or 5-day embryos are transferred if there are at least 5 embryos on day 3. Implantation of three-day embryos is most effective.

After fertilization and cultivation, embryo transfer and implantation are carried out within 1-3 days. The transfer procedure does not require anesthesia. Embryos are introduced into the uterine cavity through a special catheter to increase the chance of implantation.

Late implantation after IVF is normal. This is due to the fact that the embryo needs additional time to adapt to the internal environment of the body. Late embryo implantation during IVF should not cause concern for the expectant mother.

Our clinic performs embryo transfer and implantation. Experienced licensed doctors at our center will not only implant the embryo into the uterus, but also advise on further actions.

How does conception occur?

In order for conception to occur, the participation of two gametes is necessary - a sperm and an egg. In the first half of the menstrual cycle, the oocyte matures - under the influence of the gonadotropin FSH, it is formed in the ovarian follicle. Around the middle of the cycle, usually on the 14th day, the dominant follicle ruptures and a mature egg is released. This phenomenon is called ovulation.

After leaving the ovarian follicle, the egg travels into the fallopian tube. If sexual intercourse occurred on this day or 2-3 days before, then some of the sperm could reach the fallopian tube. It is there that the male gametes wait for the female gamete to fuse with her and fertilize her.

If there are no sperm in the oviduct, the egg continues its movement, descends into the uterus, dies and comes out along with menstrual blood. If male gametes are present, then they all together begin to attack the surface shell of the egg - the corona radiata. One sperm cannot destroy it; the effort of several is required. However, only the one who first manages to reach the inner layer - the zona pellucida - fertilizes the oocyte.

How many days does implantation take after IVF?

As in the normal course of pregnancy, implantation of the embryo after transfer during in vitro fertilization occurs within the first 40 hours after the transfer. But since embryo transfer and long-term hormonal therapy throughout the entire period of in vitro fertilization turn out to be a difficult test for women, after embryo transfer they should follow some rules:

• Limit physical activity.
• Limit visits to hot showers or baths.
• Do not lift heavy objects.
• Avoid driving.
• Take frequent walks in the fresh air.
• Don't get too cold.
• Maintain a sleep schedule.
• Wear clothes that do not restrict movement.
• Avoid sexual contact.
• Eat properly.
• Avoid visiting public places and communicating with sick people.

How to distinguish implantation bleeding from menstruation?

Light discharge associated with embryo implantation does not contain clots. They are usually pink or brown in color and last for a maximum of 3 days. With implantation discharge, the lower abdomen does not hurt, as during menstruation. In addition, much less blood is released.

Embryo implantation may cause slight bleeding. This usually does not indicate any problems, but is a normal symptom of early pregnancy, occurring in approximately 15-25% of women.

What services does our clinic provide?

Today, the method of in vitro fertilization is quite popular, since it can help solve one of the current problems - infertility. Our ART clinic employs highly qualified specialists who can provide not only the process of artificial insemination itself, but also the prevention and treatment of complicated pregnancies.

We provide individual monitoring of those pregnant women who have various diseases, for example:

• diabetes;
• bronchial asthma;
• pyelonephritis and others.

Men can also undergo comprehensive examinations Indeed, in many cases, the cause of infertility can be one of the diseases of the male body, for example, prostatitis, orchitis or prostate adenoma.

All information is for informational purposes only. If you have any health problems, you need to consult a specialist.

Signs of successful implantation

These include:

• highlighting light shades in small quantities;
• weak tingling in the chest and the same pain in the lower abdomen;
• iron taste in the mouth;
• mild toxicosis;
• increase in temperature by no more than one degree;
• feeling of self-pity;
• irritability and general weakness.

Implantation fails in two cases - in the presence of an anomaly in the genetic material and problems with the condition of the uterus. Therefore, before IVF is prescribed, a number of studies are carried out to reduce the risk of failure.