Biochemical pregnancy after IVF is a common occurrence. In this case, the embryo attaches to the uterine wall, but is rejected very soon. What is the reason for early interruption of gestation? And how to avoid this situation with the next attempt at in vitro fertilization? We will consider these issues in the article.
Definition of a concept
In obstetrics and reproductology there is the concept of "biochemical pregnancy" (BCB). This condition is not considered a pathology. This is the name of a pregnancy that terminated at an extremely short time, shortly after attaching a fetal egg to the wall of the uterus. Spontaneous abortion occurs in the first 4 weeks after conception.
According to medical statistics, 50% of women have BCB. However, the vast majority of patients do not even suspect that they were pregnant. Indeed, at such short terms, there are no clinical signs of gestation. Pregnancy is still not possible to identify with a gynecological examination or with an ultrasound scan. To find out that the process of egg fertilization and embryo implantation has taken place is possible only with the help of chorionic gonadotropin analysis or a highly sensitive pharmacy pregnancy test.
Fetal rejection at such an early stage looks like regular menstruation, which comes on time or with a very small delay (no more than a few days). Therefore, with the natural conception of BCB, it most often goes unnoticed.
Reproductive Techniques and BCB
Obstetrician-gynecologists began to talk widely about BCB after the introduction of in vitro fertilization and other assisted reproductive techniques into medical practice. These technologies have helped many patients conceive a child, even with complex forms of infertility.
However, quite often there are cases of biochemical pregnancy after IVF. What does this mean? Such statistics do not mean that reproductive techniques adversely affect the bearing of the fetus. With a natural conception, such a pregnancy occurs no less often, but in most cases it is not detected.
After IVF, the patient must take a blood test for hCG. This test is done no later than 2 weeks after the procedure. This allows you to determine the presence of pregnancy at very short times. Therefore, it is possible to track its interruption in the first weeks. BCB after in vitro fertilization is much more often detected due to early diagnosis.
Next, we will consider in detail the causes and treatment of biochemical pregnancy after IVF. The prognosis of the success of the repeated procedure is not as unfavorable as many patients mistakenly suggest.
Etiology
It is very difficult to establish the exact causes of fetal rejection shortly after implantation. Indeed, cases of BCB are also observed in completely healthy women with natural fertilization. This phenomenon is currently insufficiently studied due to difficulties in diagnosis.
Doctors suggest that the following circumstances may be the causes of biochemical pregnancy after IVF:
- hormonal disruptions;
- genetic disorders in the fetus;
- the use of drugs to stimulate ovulation;
- autoimmune reactions;
- blood diseases in a woman;
- exposure to external adverse factors.
Next, we will consider the above causes of BCB in more detail.
Hormonal disorders
The hormone progesterone is responsible for gestation, especially at the initial stage. If a woman develops a deficiency of this substance, then this can cause rejection of the embryo shortly after implantation. Doctors prescribe progesterone-based drugs to many patients after IVF, but this therapy does not always help to successfully carry the fetus.
An excess of androgens in a woman’s body can also become a cause of early abortion. Male hormones inhibit the production of progesterone.
Chromosomal abnormalities in the embryo
Reproductologists believe that genetic disorders in the fetus are the main cause of spontaneous interruption of gestation in the initial stages. This can happen against the background of the patient’s full health. The body recognizes and rejects an embryo with defective chromosomes.
Doctors are currently using preimplantation genetic diagnostics. This study allows us to detect the presence of chromosomal abnormalities in the embryo even before it is transferred to the uterus. However, this analysis is very expensive, and patients often refuse it.
Ovulation stimulation
Quite often, when applying the long protocol, there are cases of biochemical pregnancy after IVF. What it is? By protocol is meant a drug therapy regimen for inducing ovulation. Indeed, for a successful IVF, it is necessary to obtain several mature eggs.
With a long protocol, the patient is prescribed high doses of drugs with follicle-stimulating hormone. Therapy lasts about 3-5 weeks. This can affect the natural hormonal balance in the body and provoke BCB. Therefore, at present, doctors use the long protocol only for strict indications. In most cases, short stimulation with hormonal drugs is used, which lasts 12-15 days.
Other reasons
The immune system in the female body can malfunction. She can perceive the embryo as a foreign object and begin to produce antibodies against its cells. As a result, the fetal egg is rejected shortly after implantation. Such a reaction often occurs with chronic autoimmune pathologies in women, but can be triggered by accidental malfunctions.
Biochemical pregnancy after IVF is often observed in patients with blood diseases. For example, increased thrombosis (thrombophilia) can cause interruption of gestation. With this pathology, the vessels that feed the embryo are clogged with blood clots. This causes rejection of the ovum in the first weeks.
The influence of external factors
Biochemical pregnancy after IVF can be triggered by adverse external influences. The following factors can lead to interruption of gestation at an early stage;
- stress
- malnutrition;
- unhealthy lifestyle of the patient;
- general weakened state of the woman's body;
- work in harmful conditions.
Therefore, doctors strongly recommend that you prepare for pregnancy in advance. Before the IVF procedure, it is necessary to cure chronic diseases, eat well and give up bad habits in advance.
Symptomatology
What are the symptoms of biochemical pregnancy after IVF? This condition is almost impossible to notice by external manifestations, it is determined only with the help of laboratory diagnostics. After all, the fetus is rejected at such an early stage, when there is still no delay in menstruation and other classic manifestations of pregnancy (breast engorgement, morning sickness, etc.).
Miscarriage during BCB occurs during menstruation. A fetal egg comes out with blood. Allocations in this case can be more abundant than usual and contain dark red clots. Sometimes there is a slight soreness in the lower abdomen. However, in many patients, embryo rejection is unremarkable, and they take an early miscarriage for regular menstruation.
Diagnostics
A hCG blood test is the only diagnostic method for biochemical pregnancy after IVF. What it is? Chorionic gonadotropin is a hormone that begins to be produced in the body a week after conception. If its indicators are more than 5 PIECES, then this indicates pregnancy.
If the embryo has taken root and develops, then the level of chorionic gonadotropin is constantly increasing. In the first weeks of gestation, the concentration of hCG increases daily by 2 times. This is considered the norm.
After in vitro fertilization, an analysis of hCG is taken several times. This is necessary to monitor the implantation of the embryo and its further development. If the hormone level was initially high, and then fell, then this is a sign of a biochemical pregnancy after IVF. Usually, soon after a decrease in hCG concentration, the patient begins to have menstrual bleeding, and the rejected embryo comes out.
During the IVF procedure, the patient is usually given two fertilized eggs. At the same time, jumps in the hCG level may be noted. Hormone levels may fall and then rise again. This suggests that one of the embryos died, and the second took root. If the patient successfully develops both fertilized eggs, the concentration of chorionic gonadotropin is constantly growing.
You can also learn about pregnancy in the early stages with the help of pharmacy tests that respond to an increase in the concentration of chorionic gonadotropin. However, this does not replace the analysis with hCG. After all, tests do not show the exact level of the hormone. Therefore, they cannot be used for the diagnosis of BCB.
Is therapy needed
Patients are often asked about the prevention and treatment of biochemical pregnancy after IVF. Its causes are often associated with accidental failures, which may not be repeated in subsequent conceptions. BHB itself does not require special treatment. After its spontaneous interruption, there is no need for curettage of the endometrium and taking any medications. The embryo at such times is very small and completely leaves the uterus.
If gestation was interrupted at a very early date, then a comprehensive examination is necessary. This will help to identify the etiology of biochemical pregnancy after IVF. Treatment is necessary if during the diagnosis, the patient reveals pathologies that impede the safe bearing of the embryo.
Forecast
Biochemical pregnancy is far from always a sign of habitual miscarriage. This also does not indicate that the woman will have problems with conception in the future and infertility will begin. Many patients after spontaneous interruption of BCB already in the next menstrual cycle began a normal pregnancy, which was safely carried to the end.
If BCB has occurred after IVF, then doctors recommend repeated artificial insemination after 3 months. This interval is necessary to restore the reproductive system. If interruption of gestation occurred under the influence of random factors, then the chances of successful bearing subsequent pregnancies are quite high.
If a biochemical pregnancy has occurred after the transfer of cryopreserved (frozen) embryos, then a repeated IVF protocol is carried out already in the next menstrual cycle. In this case, a three-month break is not required.
With the onset of BCB, IVF attempts temporarily stop. The patient must be thoroughly examined, establish the cause of miscarriage and undergo treatment. Only then can we start a new in vitro fertilization procedure.
In medical practice, there are often cases when during the three-month interval between BCB and the new IVF protocol, a natural conception occurred. This was noted in approximately 25% of women. Most likely, this is due to the fact that in the process of preparing for artificial insemination, strong ovarian stimulation is performed. In some cases, this triggers the process of self-ovulation. The cause of prolonged infertility is eliminated, and the woman becomes pregnant naturally.
Preparing for the second procedure
For the subsequent IVF attempt to be successful, it is necessary to undergo a comprehensive diagnosis, which includes the following examinations:
- consultation of an immunologist and a hematologist;
- analysis for various types of antibodies;
- determination of the chromosome set (for both spouses);
- coagulogram.
If any pathologies were revealed during the diagnosis, then they must be eliminated before embryo transfer. In some cases, the course of therapy is required not only for the woman, but also for her spouse.
During the following protocol, careful monitoring of the hormonal background of the patient is carried out. Before embryo transfer, a detailed blood count is made for progesterone and estrogen levels. After IVF, the hCG test is taken much more often than in the previous protocol. Doctors also strongly recommend preimplantation genetic diagnosis. These measures prevent early interruption of gestation.
The opinion of patients and doctors
A fairly large number of women had cases of biochemical pregnancy after IVF. In the reviews, some patients reported that the subsequent attempt at artificial insemination was successful and they managed to safely bear the fetus.
However, the situation was often repeated, and BCB constantly came on with several attempts at artificial insemination. In this case, the patients were assigned an examination and a course of treatment. Many women note that a successful IVF attempt took place after treatment with special drugs that improve egg quality.
Reviews also report cases of natural conception after BCB. Many women managed to successfully endure pregnancy. However, in some patients there was a cessation of fetal development and miscarriage in the first trimester. This suggests that after BCB, it is necessary to undergo a comprehensive examination and identify the causes of miscarriage.
Reproductologists consider the very fact of successful embryo implantation to be a positive prognostic sign, even if subsequently the gestation was interrupted at the initial stage. If the attachment of the fetus has taken place, then this indicates a good condition of the endometrium in the patient. This means that the chances of a successful pregnancy are high enough and there is no reason to abandon subsequent IVF attempts.