Glomerulonephritis in pregnancy is an acute or chronic infectious and allergic lesion of the glomerular apparatus of the kidneys (glomeruli) that occurred before or during gestation. More than half of the cases are asymptomatic. It may manifest as a change in the color of urine to pink, reddish or brown, swelling of the face, limbs and body, increased blood pressure with dizziness, headaches, weakness. It is diagnosed on the basis of laboratory urine data, biochemical blood parameters, ultrasound of the kidneys. Treatment involves the appointment of diuretics, antihypertensive drugs, antiplatelet agents according to the indications.
The prevalence of glomerulonephritis (glomerular nephritis) during pregnancy is low: the disease is detected in 0.1-0.2% of patients. The infectious-allergic process in the kidneys, like other streptococcal infections, is more often found in young pregnant women (up to 25-28 years old). A feature of the development of glomerulonephritis in the gestational period is an extremely rare acute course, prognostically unfavorable for pregnancy. The urgency of timely detection of latent variants of inflammation is associated with the possibility of their transformation into clinically pronounced forms, in which the risk of complications increases.
The occurrence of glomerular nephritis in pregnant women is provoked by the same factors as outside the gestational period. The inflammatory-atrophic process in the glomeruli of the kidneys is often a consequence of infection, but in some patients it is caused by other conditions accompanied by the formation of immune complexes. Sometimes the etiology of glomerulonephritis remains unknown. The causes of the disease during pregnancy can be:
- Infectious agents. The main causative agent associated with glomerular inflammation is hemolytic streptococcus of group A. Less often, pathology develops against the background of diseases caused by staphylococci, pneumococci, adenoviruses, rhinoviruses, cytomegaloviruses, mycoplasmas, hepatitis B virus, HIV, pale treponemas, malarial plasmodia, etc.
- Toxic effects. In some pregnant women, an autoimmune reaction with the destruction of the glomerular apparatus begins in response to the effects of factors that provoke damage to body tissues. The starting point of inflammatory and allergic destruction of the kidneys can be irradiation, poisoning with industrial poisons, taking pharmaceuticals, drugs and alcohol, vaccination.
- Systemic diseases. The glomeruli of the kidneys can be damaged by immune-inflammatory complexes formed in autoimmune pathology. Secondary glomerulonephritis occurs in pregnant women with systemic lupus erythematosus, vasculitis, nodular periarteritis, Schenlein-Henoch disease, Goodpasture syndrome, etc. In some cases, oncopathology plays a provoking role.
According to the observations of specialists in the field of obstetrics, glomerular inflammation more often affects women who have recently suffered acute infectious diseases (sore throat, erysipelas, scarlet fever, pyoderma, acute respiratory infections) or suffer from chronic tonsillitis. An important predisposing factor is hypothermia of the body, leading to reflex vasospasm and impaired blood flow in the kidneys. Specific prerequisites for the onset of the disease are considered to be a violation of urine excretion due to changes in urodynamics and displacement of the kidneys by the growing uterus, increased load on the filtering apparatus, physiological decrease in immunity during gestation.
The development of glomerulonephritis during pregnancy is based on the destruction of glomeruli by immune complexes circulating in the blood. To bind antigens (pathogenic microorganisms, allergens, other foreign factors, in some cases, own cells), the body produces antibodies. The resulting immune complexes circulate in the blood and can be deposited in various organs and tissues, fixed by the endothelium, epithelium, basal membranes and mesangium of the kidneys. Irritation with antigen-antibody complexes triggers an inflammatory reaction with cytokine secretion, activation of intracellular proteases, migration of monocytes, leukocytes, eosinophils, which is accompanied by damage to glomerular structures. The filtering tissue is gradually replaced by the connective tissue. With the progression of glomerular inflammation, renal failure occurs.
The systematization of clinical forms of glomerulonephritis allows us to develop optimal tactics of pregnancy support to prevent possible complications. The main classification criterion is the severity of the pathology and the severity of symptoms. There are the following variants of the disease:
- Acute glomerulonephritis. Usually occurs 1-2 weeks after an infection or the action of a toxic factor. It can develop rapidly with an increase in temperature and pressure, hematuria (cyclic form), but more often it proceeds latently, subsequently it is chronicled. During pregnancy, it is extremely rare, which is associated with physiological hypersecretion of cortisol.
- Chronic glomerulonephritis. The most common variant of glomerular nephritis during gestation. It usually manifests as a latent form with minimal clinical symptoms. If the disease occurred before the onset of gestation, it may occur in nephrotic, hypertensive, mixed or hematuric type with appropriate symptoms.
The development of acute cyclic glomerulonephritis, detected in pregnant women, is indicated by complaints of weakness, pain in the lower back, headache, deterioration or disappearance of appetite, fever to 38 ° C or more, chills. Urination decreases significantly or stops completely. There is swelling of the face and eyelids. Urine becomes foamy, pink, red or brown. There may be an increase in blood pressure compared to the normal level for the patient. Symptoms of acute glomerulonephritis, as a rule, appear within 1-3 weeks after an infectious disease.
In 60-63% of pregnant women, glomerular inflammation is chronic, asymptomatic and is determined only by laboratory tests. With the hematuric form, there is usually a darkening of the urine or the appearance of blood impurities in it. In 7% of women, a hypertensive variant is diagnosed — an increase in blood pressure with complaints of general weakness, periodic headaches, dizziness, ringing in the ears. In 5% of cases, glomerulonephritis proceeds according to the nephrotic variant with pronounced swelling of the face (especially in the morning) and limbs. In severe cases, general edema (anasarca), ascites, hydrothorax, a significant increase in abdominal volume, shortness of breath, fatigue, weakness are determined. In approximately 25% of patients, manifestations of hypertensive and nephrotic forms are combined with each other with a decrease in the severity of symptoms in comparison with isolated variants of the disease.
In 35% of patients with glomerulonephritis, gestosis occurs, in 27% — nephropathy, in 8% — severe preeclampsia, in 2% — premature detachment of the normally located placenta. The risk of complications increases with hypertensive syndrome. Intrauterine fetal development delay is observed in 10% of pregnancies with normal blood pressure and in 35% — with increased. Anemia, premature birth, stillbirth. The probability of hypotonic bleeding in childbirth increases. A long-term consequence of the disorder is the more frequent development of renal pathology in children carried out by pregnant women with glomerular nephritis.
In addition to obstetric and perinatal complications during pregnancy, other disorders characteristic of the disease may develop — acute and chronic renal failure, renal colic due to blockage of the ureter by blood clots, hemorrhagic stroke, hypertensive renal encephalopathy, heart failure. Severe forms of chronic glomerulonephritis are considered as an extragenital factor of infertility – according to observations, with an increase in the concentration of creatinine in blood plasma of more than 0.3 mmol / l, pregnancy usually does not occur.
Due to the frequent absence or low severity of symptoms, laboratory and instrumental methods play a major role in the diagnosis of glomerulonephritis during pregnancy. A comprehensive examination to exclude inflammation of the renal glomeruli is prescribed with a single detection of blood and protein in the urine during laboratory screening, a persistent increase in blood pressure, the appearance of morning facial edema. The most informative studies are considered to be:
- General urinalysis. Damage to the renal glomeruli is indicated by the presence of erythrocytes, proteinuria of varying severity. In 92-97% of the tests, leukocytes and cylinders are determined. Depending on the form of the disease, the relative density of urine may increase or decrease. If necessary, the study is supplemented with urine tests according to Nechiporenko, Zimnitsky, and the Addis-Kakovsky breakdown.
- Blood testing. With glomerulonephritis with renal insufficiency, signs of impaired nitrogen excretion function are revealed. The level of serum creatinine, urea, residual nitrogen, uric acid increases. The level of albumin decreases, the cholesterol content increases to 26 mmol / l or more. The concentration of α2- and γ-globulins, seromucoid, and sialic acids increases.
- Ultrasound of the kidneys. The results of the study are more indicative of an acute process. There is a bilateral change in parenchyma. The contours of the kidneys are fuzzy. Echogenicity is increased, individual hypoechoic pyramids are detected. With renal ultrasound, the index of peripheral resistance in the arquate arteries is reduced, but in the interlobular and segmental arteries, the index of resistance is normal. In the chronic process of ultrasound, the changes are minimal or absent.
As additional methods, the Rehberg test is recommended, which allows evaluating the filtering function of the glomerular apparatus, and determining the level of C3 complement, the content of which increases during autoimmune processes. If glomerular inflammation is associated with streptococcal infection, the titer of antistreptolysin-O increases. In the general blood test, the level of erythrocytes and hemoglobin may decrease, minor leukocytosis and an increase in ESR may be noted. Radiological research methods (excretory urography, nephroscintigraphy) are not carried out during pregnancy due to possible damaging effects on the fetus. The disease is differentiated with gestosis, pyelonephritis (especially in acute course), interstitial nephritis, amyloidosis of the kidneys, kidney stones, gouty and myeloma kidney, cardiopathology. According to the indications, consultations of a nephrologist, rheumatologist, cardiologist, oncologist are recommended.
The key feature of the therapy of glomerular nephritis detected in a pregnant woman is the restriction on the use of basic immunosuppressive drugs, including corticosteroids due to the likely negative effect on the child and the course of pregnancy. The tactics of gestation management provides for compliance with the requirements of the therapeutic and protective regime, diet correction, and, if necessary, pharmacotherapy. A pregnant woman with glomerulonephritis is hospitalized twice in a specialized hospital: at 8-10 weeks — to assess the prospects of carrying a child and develop a gestation plan, at 37-38 weeks — for planned prenatal preparation. Immediate hospitalization is indicated for progressive proteinuria and hematuria, hypertension, renal failure, symptoms of fetal development delay.
In acute glomerulonephritis, strict bed rest is recommended, in clinically pronounced chronic — limited activity within the ward. Taking into account the severity of symptoms, it is necessary to reduce the amount of liquid consumed and table salt. For patients with acute forms of the disease, the amount of protein products is limited, with chronic ones – it is increased. With mild latent forms of glomerular inflammation, drug treatment is usually not used. Phytotherapy with compositions based on strawberries, bearberry, tricolor violet, yarrow, turnip, black currant is possible. In the presence of clinical symptoms, the following groups of drugs are used:
- Diuretics. With edema and decreased urination, fast-acting loop diuretics blocking the reabsorption of sodium and chlorine ions, as well as xanthines that improve renal hemodynamics, are preferred. In parallel, potassium-containing drugs are prescribed to prevent hypokalemia.
- Antihypertensive agents. The development of arterial hypertension is an indication for the use of medications that reduce blood pressure. During pregnancy, cardioselective β1-adrenoblockers, calcium antagonists, α2-adrenomimetics are most often used. Vasodilators are effective, also affecting renal blood flow.
- Antiplatelet agents. To improve the blood supply to the organs of the mother and fetus, peripheral vasodilators, purine derivatives, heparin are prescribed, which act at the microcirculatory level and prevent platelet adhesion. The use of indirect anticoagulants is limited due to the risk of hemorrhagic syndrome.
- Antibiotics are used only when infectious agents are detected. Symptomatic therapy for glomerulonephritis is aimed at increasing the level of hemoglobin (iron preparations, folic acid, transfusion of erythrocyte mass) and replenishing protein deficiency (infusion of plasma, albumin and protein solutions). Physiotherapy procedures are shown, especially pulsed ultrasound on the kidney area, which stimulates vasodilation, has a desensitizing and anti-inflammatory effect.
Usually, women with glomerulonephritis are recommended natural childbirth, caesarean section is performed according to general indications when there is a threat to the mother or child. Early delivery is carried out with unresolved gestational complications (severe gestosis, placental abruption, increase in chronic fetoplacental insufficiency, fetal hypotrophy), therapeutically resistant hypertension, rapidly progressive decrease in kidney function.
Prognosis and prevention
With proper accompaniment, most women with glomerulonephritis are able to endure pregnancy and give birth to a child on their own. Obstetricians and gynecologists distinguish three degrees of risk in the presence of the disease in a pregnant woman. Patients with latent pathology and focal changes in the kidneys belong to group 1, complicated pregnancy is observed in no more than 20% of patients. The 2nd risk group includes women with nephrotic syndrome, in whom gestation is complicated in 20-50% of cases. The maximum risk of complications with high perinatal mortality (risk group 3) is noted in patients suffering from acute glomerulonephritis, exacerbation of latent chronic, hypertensive and mixed forms of pathology, azotemia in any variant of nephritis.
Prevention is aimed at timely rehabilitation of foci of chronic infection, prevention of damaging chemical and radiation effects, justified prescription of drugs with toxic effects, exclusion of hypothermia.