Nephropathy of pregnant women is a clinical form of late toxicosis, which in typical cases includes a triad of symptoms: edema, hypertension and proteinuria. Sometimes disease is manifested by two named symptoms; rarely, with a monosymptomatic course – by one (hypertension or proteinuria). Diagnosis is based on the detection of obvious and hidden edema, increased blood pressure, protein in the urine in the third trimester of pregnancy. Treatment is carried out in an obstetric hospital and includes the appointment of a protective regime, diet, hypotensive, diuretic, sedatives.
Late pregnancy toxicosis (gestosis) includes pathological conditions that occur in the second half of gestation and pass after termination of pregnancy or childbirth. Gynecology refers to late toxicosis dropsy, nephropathy of pregnant women, preeclampsia and eclampsia, which are simultaneously stages of one pathological process. Usually, late toxicosis begins with dropsy (edema), then it can turn into nephropathy of pregnant women, preeclampsia and eclampsia. The transition from one form of toxicosis to another can be gradual, with aggravation of symptoms, or very fast, lightning-fast.
There are primary nephropathy that has developed in pregnant women with an uncomplicated somatic history, and combined late toxicosis that occurs against the background of pre-existing pyelonephritis, glomerulonephritis, hypertension, heart defects. Among the factors of perinatal infant and maternal mortality, pathology is one of the main causes. The incidence according to various studies ranges from 2.2-15.0%.
It is believed that the occurrence of nephropathy is associated with the failure of the adaptation mechanisms of the pregnant woman’s body to her new condition. Pathology is characterized by generalized spasm of arterioles, changes in hemodynamics, increased vascular permeability, decreased BCC, impaired microcirculation of vital organs, which leads to hypoxia, metabolic disorders, primarily, disruption of water-salt and protein metabolism.
There are several hypotheses explaining the causes of the development of nephropathy in pregnant women. One of the theories puts forward the moment of accumulation of harmful metabolic products in the ischemic placenta and uterus as a decisive factor. Among the toxic metabolites, there are antigens that cause the formation of antigen-antibody complexes with their subsequent settling in the kidneys and damage to the renal glomeruli. In addition, the placenta begins to produce vasopressors, which lead to a widespread spasm of arterioles. It is possible that thromboplastins coming from the ischemic placenta into the general bloodstream provoke the development of DIC syndrome, accompanied by repeated thromboembolism of the vessels of the kidneys and lungs.
Another theory of the development of nephropathy in pregnant women is based on the hypothesis of hormonal imbalance. The metabolic products accumulating in the ischemic placenta and uterus stimulate the production of prostaglandins and vasoconstrictors, adrenal hormones (aldosterone, catecholamines), the synthesis of the hormone renin by the kidneys and its extrarenal production by the uterus and placenta itself.
An essential role in the development is assigned to immunological conflicts between the organisms of the mother and fetus with the formation of CEC, including IgG, IgM, C3-complement fraction. Against this background, biologically active substances are produced in the pregnant woman’s body – acetylcholine, histamine, serotonin, etc.
In the occurrence of this disease, an important point is a violation of the function of the central nervous system, as evidenced by changes in the EEG of the brain, noted even before the development of symptoms of toxicosis. Disease develops more often during the first pregnancy, multiple pregnancy. Hypertension, obesity, heart defects, diabetes mellitus, previously suffered pyelonephritis and glomerulonephritis predispose to the development of nephropathy in pregnant women.
Circulatory disorders developing in the kidneys lead to fluid and sodium retention in the tissues (edema), the appearance of protein in the urine (proteinuria), and excessive release of renin into the blood leads to sustained vascular spasm and increased blood pressure. With nephropathy of pregnant women, the myocardium, liver, and brain vessels also suffer. Due to a violation of placental circulation, fetal hypotrophy and hypoxia may develop.
Nephropathy of pregnant women develops, as a rule, after the 20th week of pregnancy. Its occurrence is preceded by dropsy of pregnant women, characterized by the appearance of hidden and obvious persistent edema with normal blood pressure and the absence of protein in the urine. With unfavorable development, dropsy passes into the next stage of toxicosis – nephropathy of pregnant women.
A constant sign of nephropathy in pregnant women is progressive arterial hypertension with an increase in first diastolic and then systolic blood pressure. After 3-6 weeks after the detection of hypertension, proteinuria increases. The severity of edema varies from a small pasty of the hands and face to extensive swelling of the whole body. According to the severity of symptoms, there are 3 degrees of severity of nephropathy in pregnant women.
With grade I blood pressure not higher than 150/90 mm Hg; proteinuria is up to 1 g / l; edema on the lower extremities is noted. Grade II nephropathy of pregnant women is characterized by an increase in blood pressure to 170/110 mm Hg (with a pulse difference of at least 40); proteinuria up to 3 g / l, the appearance of hyaline cylinders in the urine; edema on the lower extremities and in the anterior abdominal wall; diuresis of at least 40 ml per hour. With grade III nephropathy of pregnant women, blood pressure increases more than 170/110 mm Hg (with pulse amplitude less than 40); proteinuria exceeds 3 g / l, granular cylinders are found in the urine; edema becomes generalized; diuresis decreases less than 40 ml per hour.
Also, with nephropathy of pregnant women, thirst, dizziness, poor sleep, weakness, shortness of breath, dyspepsia, flatulence, visual impairment, lower back pain are noted. When the liver is affected, there are pains in the right hypochondrium, an increase in the size of the liver, sometimes jaundice appears. In the case of myocardial damage, the development of ischemic myocardiopathy is noted.
With the early onset and prolonged course of nephropathy of pregnant women, it is more likely that it will pass into the following stages – preeclampsia and eclampsia. Nephropathy of pregnant women can lead to spontaneous termination of pregnancy, fetal development delay, premature placental abruption, fetal hypoxia or asphyxia, premature and complicated labor (labor abnormalities, bleeding).
Nephropathy of pregnant women is detected by a gynecologist observing a woman by characteristic symptoms. At the same time, the classical triad of nephropathy occurs only in 50-60% of pregnant women, the rest may have one or two signs.
The recognition of nephropathy of pregnant women is facilitated by the competent management of pregnancy with regular measurement of blood pressure, dynamic control of body weight gain, determination of the volume of diuresis, and the study of general urine analysis. To clarify the condition of the placenta and fetus, dopplerography of the uteroplacental blood flow, cardiotocography, phonocardiography of the fetus, obstetric ultrasound is performed. When examining the fundus of women with nephropathy of pregnant women, signs of narrowing of the arteries and dilation of the veins are found.
Disease is differentiated with pyelonephritis, glomerulonephritis, symptomatic hypertension, adrenal tumors (pheochromocytoma, Conn syndrome). Specialists can be involved in the diagnosis of nephropathy of pregnant women: an optometrist, a nephrologist, an endocrinologist, a neurologist, a cardiologist. Additionally, it may be necessary to conduct ultrasound of the kidneys and adrenal glands, ECG, biochemical blood and urine tests, coagulograms, urine backseeding, determination of hormones (renin, aldosterone, catecholamines).
With nephropathy, inpatient treatment is required; with I and II degrees – in the general department of pathology of pregnant women, with III degree – in the ICU. In the hospital, careful monitoring of blood pressure, electrolyte content, and kidney function is carried out.
A prerequisite for treatment is compliance with therapeutic and protective measures: bed rest, proper rest and sleep, taking sedatives. The diet for nephropathy of pregnant women consists in limiting the daily intake of salt to 1.5-2.5 g, liquid – up to 1 liter, fat. The daily diet should contain a sufficient amount of protein, fruits, vegetables, foods rich in potassium and carbohydrates. Fasting days are held weekly (kefir, dried fruit cottage cheese, etc.).
Drug therapy is aimed at relieving angiospasm, normalizing micro- and macrohemodynamics, and compensating for protein loss. In nephropathy of pregnant women, the first-line drugs are antispasmodics (papaverine, platyphylline, drotaverine), hypotensive agents (magnesia sulfate), diuretics, potassium preparations, antiplatelet agents (dipyridamole), protein preparations (plasma, albumin), etc. Infusion therapy for nephropathy of pregnant women is carried out under the control of BCC, diuresis, hematocrit, electrolytes. With nephropathy of pregnant women, sessions of hirudotherapy, oxygenobarotherapy can be prescribed. With the ineffectiveness of conservative treatment of nephropathy (within 1-2 weeks at the first art. and 1-2 days at the third art.), a pregnant woman requires urgent delivery.
With the observance of the regime and the adequacy of therapy, disease is usually curable. In the case of relief of nephropathy phenomena, pregnancy can be preserved. During childbirth, monitoring of the condition of the fetus and the woman in labor, thorough anesthesia, prevention of fetal hypoxia is required. Subsequently, it is necessary to examine the newborn for intrauterine hypoxia, intensive observation by a neonatologist. After childbirth, edema, hypertension, proteinuria disappear in a woman, kidney function is restored.
The early appearance and persistent course of nephropathy in pregnant women is prognostically unfavorable for the fetus and mother. Persistent forms of nephropathy often turn into preeclampsia and eclampsia, which can result in intrauterine fetal death and the death of a pregnant woman.
During pregnancy, it is necessary to systematically monitor blood pressure, weight gain, excretory function of the kidneys of a pregnant woman, timely detection and relief of the initial manifestations of toxicosis. Pregnant women with extragenital pathology, which serves as a background for the development of nephropathy, need particularly careful supervision of an obstetrician-gynecologist.