Chronic glomerulonephritis in pregnancy

Chronic glomerulonephritis in pregnancy (CGN) is a chronic bilateral diffuse lesion of the predominantly glomerular apparatus of the kidneys of an immune-inflammatory nature with a pronounced tendency to progression and development of chronic renal failure.

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Causes of chronic glomerulonephritis in pregnant women

In the general population of Ukraine, according to statistical studies, the frequency of chronic glomerulonephritis is 97.0 per 100 thousand of the population. 11 The frequency rate of chronic glomerulonephritis in pregnant women is 0.1-0.2%.

In 20-30% of patients with chronic glomerulonephritis, it is a consequence of acute glomerulonephritis, the causative agent of which can be streptococci (especially hemolytic streptococcus group A, strains 1, 3, 4, 12, 18), staphylococci, pneumococci, adenovirus, rhinovirus infections, mycoplasma, hepatitis B virus. In the overwhelming majority of cases of chronic glomerulonephritis of unknown etiology, we can talk about the persistence of the above-mentioned infectious factors, hepatitis B virus infection, syphilis, malaria, AIDS or the influence of pharmacological drugs, vaccines, serums, organic solvents, alcohol, etc.

The pathogenesis of chronic glomerulonephritis during pregnancy consists of the formation of an immune complex process, the components of which are the corresponding antigens, antibodies and complement factor C3. The quantitative and qualitative characteristics of immune complexes, which are formed in the circulatory bed and are fixed in the glomeruli of the kidney subendothelially, subepithelially, ingramembraneously, in the mesangium, and can be formed directly in the glomerular structures, depend on the degree of phagocytic reactivity of the organism, the quality of the antigen, the quantitative ratio between antigens and antibodies. They are also fixed in the glomeruli subendothelially, subepithelially, ingramembraneously, in the mesangium, and can be formed directly in the glomerular structures. The deposition of immune complexes initiates a cascade of biochemical cellular reactions, which are reduced to the formation of cytokines, the migration of polymorphonuclear leukocytes, monocytes, eosinophils, and the activation of intracellular proteolytic enzymes. All these processes lead to damage to the glomerular structures.

Recently, in the progression of chronic glomerulonephritis during pregnancy, great importance has been attached to the disruption of local hemodynamics, lipid metabolism, platelet activation, and the hemocoagulation system.

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Symptoms of chronic glomerulonephritis during pregnancy

During pregnancy, acute glomerulonephritis is often not diagnosed and is regarded as severe preeclampsia. The occurrence of preeclampsia before 28 weeks of pregnancy, the appearance of hematuria, the detection of elevated titers of antistreptolysin and antihyaluronidase allow us to suspect acute glomerulonephritis. Clinical symptoms of chronic glomerulonephritis during pregnancy depend on the variant, stage and phase of the disease. The most common clinical forms of chronic glomerulonephritis are those characterized by slight proteinuria, erythrocyturia without arterial hypertension. This is chronic glomerulonephritis with urinary syndrome and prehypertensive stage (latent form). The addition of arterial hypertension indicates sclerosing processes in the kidneys (hypertensive stage of glomerulonephritis). A special form of the disease, which indicates the activity of the process, is glomerulonephritis with nephrotic syndrome - the presence of edema, proteinuria over 3 g / day, hypodysproteinemia, hyperlipidemia, hypercoagulability of the blood. The next stage of the disease is chronic renal failure, which is manifested by an increase in the level of urea and creatinine in the blood, anemia, a decrease in the concentration capacity of the kidneys, arterial hypertension, dystrophic changes in other organs. It is believed that pregnancy does not occur with an increase in the creatinine content in the blood plasma over 0.3 mmol / l.

The course of pregnancy in women with chronic glomerulonephritis is complicated by the development of severe preeclampsia, anemia, intrauterine growth retardation, and premature birth. There is a risk of premature detachment of a normally located placenta and hypotonic bleeding.

There are three levels of risk that determine the frequency of adverse pregnancy and childbirth outcomes for the mother and fetus and guide the physician regarding the prognosis or treatment tactics:

• chronic glomerulonephritis with urinary syndrome and prehypertensive stage should be attributed to the I (minimum) risk level. The pregnancy period in these patients is accompanied by an increase in proteinuria in the third trimester, the development of arterial hypertension, pastosity of the lower extremities, which are most often reversible and disappear after delivery. In addition, 20% of women experience persistent clinical and laboratory remission after the end of pregnancy, possibly as a result of hormonal influence (increased production of glucocorticoids in pregnant women);
• II (expressed) degree of risk includes chronic glomerulonephritis with nephrotic syndrome and prehypertensive stage. In patients with the nephrotic form of chronic glomerulonephritis, during pregnancy, there is usually a further increase in protein loss in the urine, the development of arterial hypertension, and deterioration of renal function. In the nephrotic form of the disease and at the persistent desire of the woman, pregnancy can be maintained with the possibility of long-term treatment in a nephrological and specialized obstetric hospital;
• The III (maximum) risk level includes a combination of the hypertensive stage of the disease with chronic renal failure, acute glomerulonephritis. In this case, pregnancy is contraindicated.

Classification

The clinical classification of chronic glomerulonephritis adopted in Ukraine includes variants (urinary syndrome, nephrotic syndrome), stages (prehypertensive, hypertensive, chronic renal failure), additional characteristics (hematuric component) and phases (exacerbation, remission).

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Pregnancy management in chronic glomerulonephritis

The decision regarding the possibility of carrying a pregnancy to term should be made together with a nephrologist in the first trimester, since termination of pregnancy at a later date may lead to an exacerbation of chronic glomerulonephritis due to a violation of the rheological properties of the blood and a decrease in the production of glucocorticoids.

The patient is routinely hospitalized in a specialized obstetric hospital at least twice during pregnancy:

• up to 12 weeks to decide on the possibility of carrying a pregnancy to term, develop an individual pregnancy management plan, and predict possible complications;
• at 37-38 weeks for a comprehensive examination and treatment, dynamic monitoring of the fetus, prenatal preparation, selection of the time and optimal method of delivery.

Indications for immediate hospitalization are:

• progression of proteinuria, hematuria;
• the occurrence or progression of arterial hypertension;
• the occurrence or progression of renal failure;
• the appearance of signs of intrauterine growth retardation of the fetus.

Treatment of chronic glomerulonephritis during pregnancy

Pathogenetic treatment of chronic glomerulonephritis during pregnancy is limited due to the embryotoxic and teratogenic effects of cytostatics.

Treatment includes an appropriate regimen, diet, treatment of infection foci and symptomatic therapy.

The patients' regime excludes physical exertion, work in hazardous enterprises, associated with prolonged standing, walking, overheating, hypothermia. The work regime is sedentary, daytime rest in bed is desirable

The diet is limited to sodium chloride in the diet, control of the drinking regime, exclusion of extractive substances, spices, seasonings. It is not recommended to abuse animal fats. Products rich in potassium are prescribed, especially against the background of treatment with saluretics.

If kidney function is not impaired, enhanced protein nutrition is recommended (120-160 g of protein per day). In case of nephrotic syndrome, sodium chloride intake is limited to 5 g/day and liquid to 1000 l, in case of hypertensive stage - only salt.

Phytotherapy involves prescribing decoctions of birch leaves, cornflowers, oats, parsley seeds, kidney tea, etc.

If necessary (renal failure), diuretic drugs (hypothiazide, furosemide, uregit) can be used with additional administration of potassium preparations against the background of a potassium-rich diet.

The following antihypertensive drugs are used: methyldopa 0.25-0.5 g 3-4 times a day; clonidine 0.075-0.15 mg 4 times a day; nifedipine 10-20 mg 3-4 times a day; metoprolol 12.5 - 100 mg 2 times a day.

Antiplatelet agents are also prescribed. The dose of these drugs should be selected taking into account the level of daily proteinuria, blood coagulation system parameters, individual tolerance: dipyridamole, starting with 75 mg/day with a gradual increase in the dose (proteinuria over 3.0 g) to the maximum tolerated (225-250 mg/day).

In case of severe anemia (hemoglobin < 70 g/l) and insufficient effectiveness of hemostimulating therapy, it is necessary to transfuse washed erythrocytes or, if they are not available, erythrocyte mass. Fresh frozen plasma is used to correct hemostasis.