Pathogenesis of miscarriage.

Regardless of the cause of the threatened abortion, miscarriage always develops progesterone deficiency - a lack of the hormone progesterone that preserves the pregnancy, or a decrease in the sensitivity of the uterus to its action.

The blood flow in the uterus is disturbed, especially in the area of ​​attachment of the fetal egg, with the development of thrombosis of the vessels of the placenta.

In the case of an infectious cause of miscarriage, the damaging effect of inflammatory mediators is added to all of the above.

Under such conditions, the fetal egg cannot attach to the uterus, and its development is disturbed. It either dies or is expelled from the uterus.

Symptoms of miscarriage.

You can suspect something is wrong with the appearance of pulling pains in the lower abdomen against the background of a delay in menstruation. As a rule, a woman knows that she is pregnant, which is easily confirmed by a pregnancy test with urine, ultrasound data. In the future, these pains intensify, take on a cramping character. Bloody discharge from the genital tract appears. Their intensity gradually increases. The appearance of bleeding during pregnancy is an indication for emergency hospitalization!

With a threatened abortion (risk of discharge of the fetal egg from the uterine mucosa), only pain of varying intensity in the lower abdomen and moderate bloody discharge from the genital tract are disturbing. With a threatened abortion, the pulse and pressure do not change.

With an abortion in progress, i.e. with a miscarriage, prolonged pain in the lower abdomen increases in dynamics to intense, is cramping in nature. Bloody discharge from the genital tract becomes abundant. There may be an increase in heart rate, with heavy bleeding - a decrease in blood pressure.

With an incomplete / complete abortion, the pulling pain in the lower abdomen can change in intensity: either subside, then intensify, acquiring a cramp-like character. Bloody discharge from the genital tract is always plentiful. The uterus does not correspond to the gestational age (pregnancy) - it is reduced, softish in consistency. According to the results of ultrasound: the uterine cavity is expanded by more than 15 mm. There is no fertilized egg in it. The remains of the fertilization product in the uterine cavity are visualized.

With a frozen pregnancy, the objective symptoms of pregnancy may disappear, scanty spotting appears from the genital tract, the size of the uterus does not correspond to the gestational age.

Depending on the gestational age, amniotic fluid may be poured out. Their number depends on the gestational age. Further, in the absence of qualified assistance, the embryo or fetus is expelled from the uterine cavity.

Causes of miscarriage. Complications during pregnancy.

Complications during pregnancy:

1. Preeclampsia is a complication of the second half of pregnancy. Manifested in the form of increased pressure and the appearance of protein in the urine. It occurs as a manifestation of decompensation of the body during pregnancy. It is based on vascular spasm, ischemia (impaired blood supply) of tissues, thrombosis, circulatory disorders.

2. FPI - fetoplacental insufficiency - a violation of the function of the placenta that occurs under the influence of certain factors. In fact, insufficiency is a violation of blood circulation in the mother-placenta-fetus system.

3. Polyhydramnios.

4. Multiple pregnancy.

5. Placenta previa.

Causes of miscarriage. Violation of the structure of the uterus.

Violation of the structure of the uterus.

1. Congenital anomalies of the uterus - saddle, bicornuate uterus, intrauterine septum.

2. Uterine fibroids - the most unfavorable is the presence of a submucosal node.

3. Operations on the cervix.

4. Intrauterine synechia - adhesions after curettage, complicated by an inflammatory process in the uterine cavity.

Causes of miscarriage. Taking drugs with a toxic effect.

Taking drugs with a toxic effect, such as itraconazole (used to treat fungal diseases), methotrexate (antineoplastic drug), NSAIDs (painkillers: Analgin, Nurofen, Nimesulide, Nise, etc.) - they disrupt implantation processes due to inhibition of prostaglandin synthesis. Retinoids (teratogens), paroxetine and venflaxin (antidepressants with strong anti-anxiety effects) also have toxic effects.

Causes of miscarriage. Infections in the mother during pregnancy.

Infections in the mother during pregnancy (bacterial and viral of any localization). The most common maternal viral infections are influenza, rubella, herpes, adenovirus, mumps, and cytomegalovirus (CMV). Viruses in most cases penetrate transplacentally (through the placenta) and have a direct damaging effect on the fetal egg. CMV and herpes are characterized by an ascending route of infection.

Some diseases play a certain role in miscarriage:

• latent (hidden) infection, such as toxoplasmosis, listeriosis, etc.;

• chronic extragenital (non-gynecological) diseases: chronic tonsillitis, pyelonephritis, etc.;

• urogenital infection.

In pregnant women, colpitis is diagnosed in 55-65% of cases. At the same time, diseases of mycoplasma (25%), chlamydial (15-20%) or candidal etiology (11-15%) predominate. A feature of the causative agents of genital infections is their frequent associations, i.e., a combination of several infections.

A bacterial infection from the vagina can also spread to the urinary system, leading to the development of asymptomatic bacteriuria (the presence of bacteria in the urine). In women with miscarriage, asymptomatic bacteriuria is often detected, complicated by preterm birth (15-20%), intrauterine infection of the fetus, placental insufficiency, fetal growth retardation, and an increase in perinatal morbidity and mortality.

Causes of miscarriage. Immunological disorders.

Immunological disorders:

1. Antiphospholipid syndrome - an autoimmune process in which thrombosis of the vessels of the placental site occurs due to endothelial damage by antibodies to phospholipids of cell membranes. This leads to the emergence of macro- and microthrombi with the involvement of vessels of various caliber and localization. Antiphospholipid antibodies include: lupus anticoagulant, anticardiolipins M and G, etc.

2. Conflict on the ABO system (that is, different blood types for mother and father) or Rh factor, homozygosity of mother and father for the HLA genes (tissue compatibility systems). Pregnancy from an immunological position is an allograft (a transplant obtained from an individual of the same biological species), which has 50% paternal antigens alien to the maternal microorganism. At the same time, the normal course of pregnancy is provided by many protective factors associated with the characteristics of the immunological reactions of the mother's body.

Causes of miscarriage.

 Causes of miscarriage.

• Late reproductive age (35-45 years). With age, the frequency of miscarriage increases.

• Socio-demographic reasons: malnutrition, unsettled family life, low social status, which triggers the stress mechanism of miscarriage. Under stress, a "steal symptom" occurs - the cardiovascular and respiratory systems are activated. There is a redistribution of blood flow towards more vital organs, and the reproductive and digestive systems are "turned off".

• Toxins and occupational hazards: ionizing radiation, pesticides, inhalation of harmful gases.

• Bad habits.

• Chronic diseases of the mother: diabetes, thyroid disease, obesity.

Causes of miscarriage. Gene and chromosomal abnormalities of the embryo/fetus.

Gene and chromosomal abnormalities of the embryo/fetus:

• Frequent chromosomal abnormalities:

• monosomy X (45X) - Shereshevsky-Turner syndrome (the absence of one X chromosome in girls);

• trisomy (additional chromosome) (47XXY) – Klinefelter's syndrome (additional female sex chromosome X in male XY karyotype);

• trisomy 13 chromosomes - Patau's syndrome;

• trisomy 16 chromosomes - spontaneous abortion;

• trisomy 18 chromosomes - Edwards syndrome;

• trisomy 21 chromosomes - Down's syndrome.

• Chromosomal rearrangements:

• failure of meiosis in any period of division (meiosis is the process of division of the mother cell with a complete set of chromosomes, in which germ cells (gametes) with a half set of chromosomes are formed);

• failure during fertilization - dyspermia (fertilization by two or more spermatozoa) with the formation of a polyploid embryo;

• failure during the first mitotic divisions of a fertilized egg (mitosis is a process of cell division in which daughter cells have a complete set of chromosomes);

• chromosomal translocations in one of the partners: 1) Reciprocal translocations - two fragments from two different chromosomes break off and change places. 2) Robertsonian translocations - one chromosome connects to another.

What is a miscarriage?

Miscarriage is a spontaneous termination of pregnancy at any time from conception to full term (37 weeks).

Loss of pregnancy before 22 weeks is a spontaneous miscarriage. If the pregnancy is terminated after more than 22 weeks, it is already considered to be a preterm birth. Losing a pregnancy three or more times is called recurrent miscarriage. If the dead fetus or embryo is asymptomatic for some time in the uterine cavity, such a pregnancy is called frozen. The category of missed pregnancies includes anembryony, in which an empty fetal egg is determined in the uterine cavity.

The frequency of miscarriage is from 15 to 20% of all diagnosed pregnancies. The frequency of interruption in the first trimester reaches 50%, in the second trimester it is about 20%, and in the third trimester - up to 30%.