Biochemical pregnancy - spontaneous interruption of gestation at the stage of implantation of the ovum into the uterine wall. The essence of the phenomenon lies in the absence of any visible changes in the woman's body - toxicosis, bleeding, pulling pains in the abdomen, etc. Confirmation of the fact of short-term pregnancy is possible only in the case of tests for the content of hormones.
What is biochemical pregnancy?
The process of development of the embryo in the reproductive organs of a woman begins at the moment of the fusion of the nuclei of the sperm and the oocyte (egg) and its subsequent introduction into the wall of the uterus. Through the mucous membrane of the endometrium, the ovum receives from the mother's body all the nutrients necessary for its further development.
In some cases, gestation is interrupted almost immediately after embryo implantation. In medical terminology, this condition is called preclinical spontaneous miscarriage (PSV). Rejection of a fertilized oocyte occurs in the first 10-14 days after conception. Due to the practical absence of changes in the work of the reproductive and endocrine systems, gestation is not diagnosed in any way.
HCG in biochemical pregnancy
Clinical manifestations of biochemical pregnancy are weak or absent altogether. In most cases, your period starts on time or with a slight delay. The fact of conception and spontaneous abortion is not determined by palpation or ultrasound.
Preclinical spontaneous miscarriage can be detected only with the help of laboratory analysis for the content of human chorionic gonadotropin (hCG). This hormone begins to be produced by embiological structures (chorion) 6-7 days after implantation of a fertilized oocyte into the uterus.
Signs of biochemical pregnancy
For most women who are not planning a pregnancy, PSV is almost asymptomatic. Minor changes in the woman's body are still present, but do not cause serious discomfort. The clinical manifestations of short-term gestation include:
- delay in menstruation for several days;
- dysmenorrhea;
- profuse discharge during menstruation.
In about 93% of cases, the above symptoms are mild, so women do not pay any attention to them. Preclinical spontaneous miscarriage does not indicate the development of pathologies in the reproductive system. According to obstetricians and gynecologists, most women faced such a problem personally, but this did not prevent them from subsequently becoming pregnant and carrying a child.
Causes of biochemical pregnancy
The mechanism of development and the causes of PSV have not yet been established. According to one hypothesis, embryo rejection occurs when there are malfunctions in the functioning of the endocrine and immune systems.
In most women, with the onset of gestation, the reactivity of the body decreases, which is associated with the production of specific protein factors by the embryo. It is they who suppress cellular immunity, which subsequently prevents the rejection of the embryo.
According to the results of many years of observations, preclinical spontaneous miscarriage can be caused by the following reasons:
- insufficient production of progesterone;
- autoimmune disorders;
- blood pathology (thrombocytosis, thrombocytopenia);
- immune disorders;
- dysfunction of the hypothalamic centers;
- genetic abnormalities of the embryo.
According to most reproductologists, spontaneous abortion in early gestation is caused by immunological changes. Most often, PSV occurs in women who have had serious diseases - generalized staphylococcal infection, parotitis, fungal myometrium, etc.
Biochemical pregnancy after IVF
In vitro fertilization (IVF) does not guarantee a favorable course of pregnancy. According to statistics, only in 35-40% of cases, embryo replanting leads to its implantation into the uterine wall. In all other cases, preclinical spontaneous miscarriage occurs.
To prevent embryo rejection, embryo replanting is carried out only after hormone therapy. The success of the procedure depends on the state of the endometrium and hormonal levels. The transplantation of the ovum into the uterus is performed at the time of the maximum increase in the reparative properties of the endometrium.
When using in vitro fertilization for the first time, chorionic gonadotropin is determined in the systemic circulation on the 14th day after the procedure. The serum concentration of the hormone depends on the duration of the infusion and the characteristics of the course of pregnancy:
- hCG value is below normal - there is no gestation;
- the concentration of hormones at the border of the norm - ectopic pregnancy;
- increased concentration of hCG - fetal pathology or diabetes mellitus in the mother.
During biochemical pregnancy after IVF, the level of chorionic gonadotropin increases greatly, but when the embryo is rejected, it rapidly decreases. Signs of the onset of gestation are absent, as well as signs of its interruption.
Pregnancy after biochemical pregnancy
Preclinical spontaneous miscarriage is not a manifestation of pathologies that entail infertility. Biochemical pregnancy does not affect the functioning of the reproductive system and does not impair the ability to conceive or carry a fetus.
It is possible to suspect miscarriage only if it is repeatedly interrupted in the early stages. Recurrent preclinical spontaneous miscarriages may indicate disturbances in the functioning of the ovaries, thyroid gland and other organs of the reproductive and endocrine systems.
Conclusion
A spontaneous abortion early in gestation can be caused by autoimmune disorders, blood disorders, and genetic abnormalities in the embryo. Biochemical pregnancy does not manifest itself in any way, so most women do not even know about its onset and interruption. A single spontaneous miscarriage does not indicate the development of pathologies and does not create obstacles to the repeated conception and bearing of the fetus.
