Tendency to thrombosis during pregnancy - minimal panel

Test material: Whole blood (with EDTA). Determination method - Real-time-PCR.

You can take a blood test for a tendency to thrombosis during pregnancy - a minimal panel at the nearest INVITRO medical office. A list of offices where biomaterial is accepted for laboratory research is presented in the “Addresses” section.

Interpretation of study results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. The doctor makes an accurate diagnosis using both the results of this examination and the necessary information from other sources: medical history, results of other examinations, etc.

Detailed description of the study

The balance of the action of the coagulation and anticoagulation systems of blood in the body (hemostasis) is maintained through many reactions and the complex interaction of proteins with each other. Against the background of severe illnesses, injuries and burns, surgical interventions and some other pathological conditions, disseminated internal coagulation syndrome (DIC syndrome) may develop.

In disseminated intravascular coagulation syndrome, hemostasis is impaired, and against the background of an increased tendency to bleeding, blood clots—thrombi—form in the vessels.

Normally, fibrin protein is an intermediate product formed when fibrinogen is destroyed by another protein, thrombin. These substances are one of the key blood clotting factors.

In intravascular coagulation disorders, thrombin levels are low and the amount of fibrin is insufficient to form a clot. Instead, it binds to fibrinogen or its breakdown products, resulting in the formation of soluble fibrin-monomer complexes (SFMCs). Thus, RFMKs are microthrombi found in the blood.

If the concentration of RFMC increases, this indicates an increased tendency of the body to form blood clots.

The formation of blood clots usually requires a combination of unfavorable factors, such as hereditary predisposition, decreased physical activity, and insufficient fluid intake.

One of the conditions in which there is a tendency to blood clots is pregnancy. The formation of microthrombi in a woman’s body can impair blood flow in the placenta and lead to pregnancy loss.

Determination of the RFMK indicator can be carried out to identify disseminated intravascular coagulation syndrome, the causes of thrombosis, their risk during pregnancy, as well as during heparin treatment. The test is used for indirect diagnosis of placental blood flow disorders; together with coagulogram indicators, it helps to identify impaired hemostasis.

Decoding indicators

A description of the results is given by a geneticist.
A genetic blood test for the presence of polymorphisms in the prothrombin (F2) and Leiden factor (F5) genes reveals the patient's predisposition to thrombosis.

Genetic polymorphism, or genetic diversity, is different variations of genes. The presence of gene polymorphism explains disturbances in the structure and properties of those proteins that are produced in the body. With genetic polymorphism, changes in the function of synthesized proteins can be beneficial for the body, neutral or negative.

The F2 gene encodes the amino acid sequence of the protein prothrombin (a protein called blood clotting factor II, which is produced in the liver and is a precursor to thrombin). The presence of polymorphisms in the F2 gene leads to an increase in prothrombin several times, which increases the risk of venous thrombosis, including thrombosis of the brain and heart, especially at a young age. The mutation has an autosomal dominant type of inheritance, so even a heterozygous carrier of the altered gene suffers from thrombophilia. Patients who carry this altered gene have an increased risk of developing fetoplacental insufficiency, placental abruption, fetal growth retardation, fetal loss in the first trimester of pregnancy, and the development of thromboembolism after surgical interventions. Taking oral contraceptives in this group of people also increases the risk of thrombosis.

The F5 gene encodes the amino acid sequence of the protein proaccelerin - coagulation factor V, which is synthesized in the liver, participates in the blood coagulation cascade, and activates the transition of prothrombin to thrombin. A change in the gene (replacement of arginine with glutamine at position 534 - “Leiden mutation”) makes the active form of coagulation factor V resistant to cleavage, which is manifested by recurrent venous thrombosis and thromboembolism. The presence of the mutation increases the risk of venous thrombosis by more than 3 times. Taking oral contraceptives increases this risk by more than 30 times. The risk of myocardial infarction increases by more than 2 times, the risk of developing pregnancy pathologies (miscarriage, preeclampsia, chronic placental insufficiency and fetal growth restriction syndrome) increases by more than 3 times.

Patients who are carriers of both the prothrombin gene mutation and the Leiden mutation are even more at risk of developing thrombosis and thromboembolism.

Conference “Modern methods of treatment of oncological and oncourological diseases”

A hemostasiogram is an extended study of the hemostasis system. In state medical institutions of the Russian Federation, as a rule, a shortened version of this analysis is carried out (coagulogram), which includes indicators such as:

• Fibrinogen is a protein dissolved in blood plasma that usually does not interfere with normal blood circulation. However, if the coagulation system is activated, it is converted into fibrin, the threads of which form the basis of a clot that covers the damaged area and thereby stops bleeding. The higher this indicator, the greater the thrombogenic potential of the blood.

Normally, this indicator varies from 2 to 4 g/l. The concentration of fibrinogen during gestation is higher and in later stages can be about 6-7 g/l.

• APTT (activated partial thromboplastin time) is the period of time during which, subject to the addition of certain activating substances, a blood clot is formed. The normal range is 28-40 seconds. An increase in values ​​indicates a slowdown in clot formation, a decrease indicates an acceleration. It should be borne in mind that deviations in one direction or another are not an indicator of a blood clotting disorder, since they can be observed when taking certain thinning agents, as well as in autoimmune pathologies (that is, such results may be a reason for an in-depth examination).
• INR (international normalized ratio) allows for monitoring of coagulation in patients prescribed the anticoagulant warfarin. For each patient, a range of normal values ​​is determined (usually 2-3), which in the absence of taking the drug are lower. It must be borne in mind that this is the only situation where the assessment of this indicator matters.
• PTI (prothrombin index), PTT (prothrombin time), prothrombin according to Quick - all these indicators allow you to evaluate the activity of prothrombin (a protein that, as the name suggests, is a precursor of thrombin - the enzyme under the influence of which fibrinogen is converted into fibrin).

Normal Quick prothrombin values ​​range from 70 to 120%. A decrease in values ​​indicates a tendency to thrombosis, an increase indicates a tendency to bleeding. At the same time, of course, it should be borne in mind that it is impossible to make a diagnosis based on a single change in a single indicator.

A hemostasiogram, in addition to standard ones, may include the following indicators:

• SFMC (soluble fibrin-monomer complexes) reflect thrombus formation activity. Normally, the values ​​should not exceed 4.0. It should be borne in mind that during pregnancy the level of RFMC increases markedly, reaching 12-15 in the later stages. An increase in values ​​indicates excessive activity of the coagulation system, but treatment is not always required. If the patient has thrombotic risk factors, an increase in indicators may be a reason to prescribe thinning drugs. If a healthy woman has no risk factors, even very high values, as a rule, do not require correction.
• D-dimer is a fibrin breakdown product, a kind of clot debris that remains after it dissolves. Conventionally, values ​​up to 250 ng/ml are considered normal.

Increased values ​​are possible with thrombosis. During gestation, a high D-dimer may be normal. In particular, in later stages, even an increase in the value up to 1000 ng/ml, as a rule, is not considered critical. However, when monitoring a pregnant woman, it is necessary to evaluate changes in values ​​over time. During the entire period, an increase in the initial indicators by three to five times is permissible. In this case, the assessment of current values ​​should be based on previous results. Sometimes an extremely high level can be observed in a completely healthy woman, and this does not interfere with the normal course of pregnancy, and also does not require therapeutic measures.

• Hageman-dependent and euglobin lysis makes it possible to assess the rate of dissolution of existing clots and understand how quickly vascular patency is restored.

If the slowdown in lysis is significant (Hageman-dependent exceeds 12 minutes, euglobin-dependent - 240-250 minutes), then even a slight increase in thrombus formation can provoke vascular complications. During the gestation period, this is fraught with termination of pregnancy in the early stages. In addition, slower lysis may be one of the reasons for IVF failure.

• Plasminogen is an enzyme that carries out lysis (fibrinolysis). Often, it is not the rate of lysis that is determined, but its activity as a percentage of the norm. If it is reduced (to 75% or less), then even a slight increase in thrombus formation can provoke vascular complications. If it is increased (up to 160% or more), the risk of bleeding increases when taking thinning medications.
• Antithrombin is a natural anticoagulant that prevents excessive thrombus formation. If the antithrombin level is less than 70%, this indicates a high risk of thrombosis. Increasing values ​​is not dangerous.
• Platelet aggregation is the process of cells sticking together to form clots. As aggregation decreases, wound bleeding time may increase. An increase in aggregation, on the contrary, can provoke causeless thrombus formation.

The study can be performed either spontaneously or with the addition of certain inducers (for example, collagen). For each of these analyzes there are separate standards. In different laboratories they differ depending on the available reagent base.

I would like to note that when deciding on the need for therapy, the doctor must take into account the results of the hemostasiogram, but primarily relies on the collected anamnesis and the presence of risk factors. In obstetric practice, the course of pregnancy must be assessed. Thus, treatment can be prescribed even if the study results are excellent, but if there are abnormalities, on the contrary, there may be no need for it.

Planning a pregnancy

• Psychological preparation, positive psychological attitude
• Maintaining a healthy lifestyle (giving up bad habits, proper nutrition, eliminating harmful household and industrial factors, moderate physical activity)
• Weight correction
• Taking folic acid (to prevent fetal neural tube defects)
• Identification and treatment of chronic extragenital diseases (diabetes mellitus, hypertension, kidney disease, etc.)
• Consultations with specialists (gynecologist, dentist, ophthalmologist, otolaryngologist, therapist, geneticist if necessary, specialists in the profile of the disease in the presence of chronic extragenital pathology, other specialists as indicated)
• Instrumental examination methods (ultrasound of the pelvic organs, ultrasound of the mammary glands, colposcopy if indicated)
• Laboratory research

Laboratory tests recommended when planning pregnancy for a woman

• blood for HIV, syphilis, hepatitis B and C
• general blood analysis
• blood type and Rh factor
• general urine analysis
• study of thyroid hormones (TSH, T3, T4)
• blood chemistry
• tests for TORCH infections (this is a number of the most dangerous infections during pregnancy: toxoplasmosis, rubella, cytomegalovirus, herpes)
• flora smear
• PCR test for urogenital infections (UGI) - chlamydia, ureaplasma, mycoplasma, etc.
• cytological examination of scrapings from the cervix
• PCR testing for human papillomaviruses (HPV)
• study of blood hormones: FSH, LH, prolactin, estradiol, progesterone, testosterone, etc. (according to indications)