Protein in urine analysis, or proteinuria: classification, causes and principles of therapy. What does increased protein in urine tell you about during pregnancy Protein in urine during gestation

Urine is a by-product of the vital activity of the human body, based on the state of which and the presence of various substances in it, a conclusion is made about the state of human health. Passing through the urinary tract, urine washes away pathogenic microflora, chemical macro and microelements, the concentration of which increases with the development of inflammation and infections.

- one of the pointsgeneral urine test, which shows the concentration in biological fluid squirrel . The results of the study make it possible to determine the presence of pathological processes and inflammation in the body at their early stages. The analysis is carried out both in the presence of certain symptoms that are highly likely to indicate a disease, and for preventive purposes.

Daily proteinuria, what is it?

Protein is an organic compound, a necessary element for cells, their “building” material. Urine with normal health statushuman must be pure, that is, not contain any organic compounds, including protein, or their concentration must be minimal.

If the amount of protein in the urine exceeds the norm, this is a sign of the development of inflammatory or infectious diseases in the body, or an exacerbation of chronic pathologies.

Daily proteinuria - urine test for determination concentrations protein - albumin and immunoglobulin. Urine analysis for determination daily proteinuriais given in the following cases:

• malignant formationsdifferent locations;
• infectious diseases of the bladderand other organs of the urinary system;
• autoimmune pathologies.

It is mandatory to take a test to determine daily proteinuria during pregnancy. At least once every 3 months, a urine test must be taken by people with chronic diseases at the stage of remission.

Urinalysis and albumin

Protein is a high-molecular organic substance, represented in the human body by two elements - albumin and immunoglobulin. Albumen – a protein with a low molecular weight is soluble in water.

Globulin is a protein that has a low degree of solubility in an aqueous environment and has a high molecular weight.

Albumins are quite large in size and cannot enter the urine due to renal glomeruli , performing the function of a filter. If albumin is found in the urine, it means that the renal glomeruli have ceased to perform their functions. This is observed in inflammatory and infectious diseases of organsurinary system. The higher the protein concentration substances in biological fluid, the more intense the severity of the disease.

Detection of globulins in urine is extremely rare. Albumins in low concentrations are more common, and often their appearance in urine is physiological, not pathological. Until the end of the 20th century, the presence of albumin in the blood was classified as a separate pathology, which was called albuminuria.

Preparing for urine testing

An analysis to determine the concentration of protein in the urine is essential for making a diagnosis. In order for the analysis to give an accurate result, it is necessary to properly prepare for it. A few days before collection urine, the patient should refuse:

• alcoholic and alcohol-containing drinks;
• foods high in vitamin C;
• taking diuretics;
• physical activity.

Before, how to get tested, for 1-2 days it is important to maintain emotional stability, protect yourself from stressful situations and mental shocks.

The peculiarity of collecting urine for analysis for proteinuria is that it is necessary to collect daily urine. If a person collects urine for the first time at 7 am, the last collection should be at 7 am the next day. During days urine is collected in one large, sterile container. During the day, urine should be stored at a temperature of 2 0 C to 8 0 C above zero.

For analysis, you need to take 50-70 ml from a common container and drain the urine intospecial containerpurchased at a pharmacy. Before taking the required amount of urine, the jar with the total amount of urine should be shaken well. The patient needs to write down how much fluid was obtained per day.

The collected urine must be taken to the laboratory within 2 hours after the last urine collection.

The test is not performed if the patient has viral and infectious diseases, such as colds and flu. First you need to visit ENT doctor , get an order from him to medicine , which will not provoke an increase in protein in the urine. After complete recovery, at least 2-3 days should pass before collecting urine for research daily proteinuria.

Urine protein standards for adults (men, women, pregnant women)

Normal indicatorsprotein(protein) in adults and women during pregnancy:

Indicators of proteinuria in pregnant women are individual. The norm is considered to be an increase in protein concentration to 0.14 g/l.

Causes of protein in urine

The presence of proteins in human biological fluid can be non-pathological in nature, that is, be a physiological norm and pathological, caused by the presence of certain diseases.

Non-pathological factor

A physiological increase in protein in urine can be caused by the following factors:

• improper, unbalanced diet;
• excessive physical activity;
• hypothermia of the body.

If a person daily eats food in which protein predominates, the concentration of protein in urine will differ more from indicators norms. It is enough to balance the diet so that it contains protein, fats and carbohydrates in order to eliminate physiological proteinuria.

Another reason for increased protein in collected urine is regular physical activity. Physiological proteinuria is observed in professional athletes.

Infectious diseases

Norm of proteinuria indicators always increases in the presence of infectious diseases. These are not always diseases of the urinary system. There is a concept -orthostaticproteinuria, which is observed in young children and adolescence.

Orthostatic proteinuria is the presence of a high concentration of protein in the urine due to the development of acute or chronic infections, regardless of the location of the pathogenic focus. The body can respond by increasing protein to the development of influenza, otitis media and other diseases of the respiratory system.

Internal injuries

Proteinuria increases with anypathological changesin the condition of the internal organs. Protein appears in the urine after traumatic brain injury, which is accompanied by brain damage. Temporary proteinuria is observed after surgery.

Burn disease

Burns are accompanied not only by a violation integrity skin and soft tissues, but also the development of necrotic processes, as a result of which the body experiences severe intoxication. Due to intense poisoning they suffer kidneys , which cannot perform their function, the renal glomeruli lose their filtration properties, passing through a large amount of protein.

When a burn injury occurs renal form proteinuria, when cells do not receive the required amount of oxygen, blood circulation is disrupted, and protein enters the urine directly from the bloodstream.

Radiation damage

Radiation nephropathy is kidney damage caused by high doses of radiation. Pathology may occur due to frequent x-rays, or the administration of certain medications that contain radionuclides. Radiation damage occurs in people employed in hazardous industries.

Harmful substances are retained in the kidneys, leading to structural and functional changes in the soft tissue of the organ. The kidney glomeruli are affected and stop retaining protein.

Urolithiasis disease

One of the most common causes of proteinuria is the development of urolithiasis. Protein appears in the urine long before a person develops the first signs of illness. Protein concentration increases as the pathology develops. Symptoms accompanied by disease:

• lower back pain that constantly gets worse;
• urinary disturbance;
• pain and discomfort in the lower abdomen;
• change in urine color;
• increased body temperature;
• deterioration of general condition.

Diagnostics with these signs, it always includes testing for proteinuria.

Oncology

The development of an oncological tumor is always accompanied by an increase in protein concentration. As the tumor grows, it begins to compress the blood vessels, impairing blood circulation. Stagnation of blood leads to the development of the glomerular form of proteinuria.

Proteinuria occurs regardless of the organ in which the neoplasm is localized. When a tumor damages bone tissue, leading to its disintegration, the products of this process penetrate into the bloodstream, from which they enter the urinary system and are excreted from the body with urine high in protein.

Protein in urine during gestation

During pregnancy, the kidneys experience increased stress, which is why the presence of low protein concentrations is normal. The reason for the development of proteinuria during pregnancy is that a woman’s blood pressure increases, including in the kidneys. Increased pressure causes damage to small capillaries, glomeruli and protein molecules. The protein passes through the holes in the glomeruli, ending up in the urine.

The destruction of small capillaries with further release of protein into the urine is caused by the increasing size of the uterus, which compresses the blood vessels, leading to stagnation of blood in the pelvis.

In the absence of inflammatory and infectious diseases, the presence of protein in the urine of a pregnant woman is normal. After childbirth, protein will disappear from urine.

If the analysis for daily proteinuria showed an increased protein content, do not panic, thinking about the worst. The concentration of protein in daily urine is influenced by many factors, such as physical activity and emotional instability. There is always the possibility that the person did not follow the recommendations for collecting urine, which led to a false result.

If the patient does not have symptoms indicating the development of any pathologies in the body, it is recommended to take the test for daily proteinuria again to exclude a diagnostic error.

Treatment of proteinuria is closely related to the cause of its occurrence. Until the factor that led to the appearance of protein in the urine is eliminated, therapy will not have a positive therapeutic effect. To reduce protein in the urine, drugs from the stanine group, calcium channel blockers and ACE inhibitors are prescribed.

Additionally, folk recipes can be used, for example, decoctions based on herbs and natural ingredients - chamomile, St. John's wort, oak bark. Such decoctions will help relieve inflammation in internal organs, thereby reducing the concentration of protein in urine.

In addition to treating the cause of proteinuria and taking medications, the patient will have to follow a low protein diet and natural diet, without adding any flavor enhancers to foods, vegetables and fruits, lean meat.

Conclusion

Daily proteinuria is an analysis showing the state of a person’s health, helping to determine the presence of pathological processes. Based on the results of a laboratory test, it is possible to identify both simple infections of the urinary system and severe, life-threatening pathologies, such as the presence of cancer.

Analysis to determine daily proteinuria is recommended not only for people with chronic diseases, but also as a preventive measure. Many diseases, including the formation of cancer, occur in a latent form and are not accompanied by any signs for a long time. They are detected by undergoing a laboratory test for daily proteinuria.

Considering the diagnostic value and information content of laboratory urine testing, it is important to carefully follow the recommendations regarding preparation for collecting biological material in order to eliminate diagnostic errors.

Pregnancy occurs with some disturbances in the normal functioning of the woman’s body. The restructuring of internal organs and systems leads to changes in their work, which are revealed in laboratory tests. One of the common symptoms is proteinuria during pregnancy.

Proteinuria is a pathological condition in which the permissible amount of protein in the excreted urine is exceeded. The process of filtering urine from the blood occurs in the glomeruli. The surface of their walls does not allow protein molecules to pass through, so its amount in excreted urine is minimal. The normal level of protein in urine is 0.033 g/l in one portion of the test material.

The level of protein in urine during pregnancy changes, the maximum permissible limit is reduced.

Limits of normal protein content in urine:

• 1st trimester - maximum content is no more than 0.002 g/l;
• 2nd trimester - limit not more than 0.1 g/l;
• 3rd trimester - maximum value 0.033 g/l.
• Normal daily proteinuria is 0.08-0.2 g/day.

The symptom is a sign of pathology of the urinary system and other diseases. When carrying a fetus, it indicates a complication of pregnancy called gestosis. Most often appears in the 3rd trimester after 30 weeks.

Causes

There are physiological reasons for increased protein content in the urine, associated with eating large amounts of protein foods, stress and physical activity. During pregnancy, this occurs due to the woman’s body adapting to bearing a fetus. An increase in the size of the uterus leads to compression of the kidneys and bladder. The organs of the urinary system work with double the load. Proteinuria caused by pregnancy occurs due to an increase in the level of hormones that affect the condition of the vascular membrane. Pathological causes are kidney disease, chronic or newly acquired vascular disorders.

The amount of protein in the urine indicates the state of the pregnant woman’s kidneys. The future health of the woman and child depends on this.

Reasons for the development of pathology:

1. Pyelonephritis is an inflammatory disease of the kidneys that affects the parenchyma of the organ. The causative agents are pathogenic microorganisms that attack a woman’s weakened immune system during pregnancy. Proteinuria is observed in the presence of chronic pyelonephritis in the mother. The disease leads to disruption of the kidneys, in particular, the tubular urine filtration system.
2. Glomerulonephritis is a kidney disease affecting the glomerular system of the organ. The transition to a chronic form of the course is dangerous for pregnant women.
3. Hypertension is a persistent increase in blood pressure. The presence of vascular pathology in a woman’s history leads to the development of pregnancy complications with proteinuria in the analysis.
4. Systemic autoimmune diseases. Diseases of this group are aggravated during pregnancy, there is a risk of impaired renal function, which is manifested by proteinuria.
5. Diabetes mellitus is a disease of the endocrine system, leading to pathology of blood vessels. The filtration capacity of the kidneys depends on the condition of the walls of blood vessels.
6. Preeclampsia is a pathological condition characterized by high blood pressure, vomiting and seizures. It is a complication of pregnancy. A urine test reveals a large amount of protein.
7. Preeclampsia is a general definition of symptoms of toxicosis during pregnancy. The cause is chronic diseases of women, Rh conflict between mother and fetus, and hormonal imbalances.

Proteinuria in pregnant women is a dangerous condition and, when detected, requires a detailed examination of the woman.

Clinical manifestations

Diagnosis of proteinuria during pregnancy indicates the presence of the disease in the mother. Any violation affects the growth and development of the fetus and therefore requires medical intervention. Proteinuria in pregnant women is a symptom of many diseases, so the clinical manifestations of this disorder are as follows:

• increased body temperature;
• nausea and vomiting;
• high blood pressure;
• swelling;
• exacerbation of symptoms of chronic diseases;
• lower back pain.

The presence of proteinuria indicates the risk of developing severe gestosis. This condition is caused by insufficient functioning of a woman’s organs and systems due to the restructuring of the body for bearing a fetus. Toxicosis develops, which is a dangerous complication for the health of the mother and child. In the most difficult cases, eclampsia appears. The woman's condition is very serious, characterized by convulsive syndrome, high blood pressure, impaired urine outflow, and severe swelling. Possible loss of consciousness.

There are 4 stages of development of gestosis:

• Mild - minor swelling of the lower extremities, pressure rises to 150/90 mm Hg. Art. A woman often does not attach importance to the first signs of gestosis. The protein level is 0.033-0.1 g/l.
• Moderate - swelling intensifies and spreads to the abdominal area, sometimes the face, pressure rises to 170/100 mm Hg. Art. Protein level - up to 1 g/l.
• Severe - deterioration in general condition, swelling spreads to the entire body, pressure reaches 200/110 mm Hg. Art. More than 1 g of protein is found in the urine.
• Eclampsia - loss of consciousness, convulsions, vomiting, blood pressure 200/110. Lack of timely medical care is dangerous for the development of severe complications.

Severe gestosis is dangerous due to impaired blood supply to the brain, pathology of the nervous system, cardiovascular failure, loss of vision, and the development of coma.

Diagnosis and treatment

Protein tests are mandatory tests for pregnant women. The purpose of the study is determined by the doctor leading the pregnancy. A special container is used to collect urine; a specialist correctly explains how to donate the material. The analysis requires a daily portion of urine, that is, the material is collected throughout the day and night.

The first portion after waking up goes down the toilet. Collect subsequent secretions in a container and store in a cool place. After collecting the last portion, mix the contents and separately collect 35-40 ml of urine, deliver to the laboratory within 2 hours.

The day before collecting the material, factors that affect protein levels should be eliminated:

• protein foods;
• stressful situations;
• medications;
• hypothermia;
• excessive physical activity.

Elimination of proteinuria is carried out by treating the cause of its occurrence. In the presence of chronic diseases, therapy is aimed at easing their course. If the cause of protein in the urine is gestosis, the patient is hospitalized in an inpatient department and is under the supervision of a doctor. Only the mild stage allows outpatient treatment.

Therapy for eclampsia is reduced to relieving symptoms, alleviating the condition of the pregnant woman and preventing complications of the child’s condition. At the hospital stage, the patient receives vascular drugs, anticoagulants, anticonvulsants and diuretics.

If the protein level is slightly exceeded, it is recommended to drink more fluid and normalize the diet.

Prevention of proteinuria during pregnancy

The statistics of proteinuria during pregnancy indicate a frequent manifestation of the pathology. To monitor the progress of pregnancy, women undergo blood and urine tests every month. After 30 weeks and if there is a risk of preeclampsia, the tests will have to be repeated once a week. The monitoring is carried out by a doctor, but it is possible to detect changes in the composition of urine on your own. To prevent gestosis in the early stages, it is necessary to monitor the quality of urine excreted. The detection of a large amount of foam on the surface of the urine indicates that the protein level is exceeded. In this case, the gynecologist is notified.

To prevent the dangerous condition of eclampsia, pregnant women undergo repeated laboratory tests every trimester. The presence of chronic kidney disease indicates the risk of developing preeclampsia. In such cases, women are prescribed the correct diet with limited salt and sufficient fluids. At each scheduled visit to the doctor, you will have to measure your blood pressure and monitor your weight gain.

A 24-hour urine test for protein is prescribed for the diagnosis and monitoring of kidney diseases, diabetes and infectious diseases, as well as in a number of other cases. The study makes it possible to distinguish physiological proteinuria from pathological one. To obtain reliable results, it is necessary to follow the rules for collecting material.

Urine is a biological fluid that is formed by the kidneys and contains metabolic products intended for excretion from the body. It is formed as a result of blood passing through the glomerular filter of the kidneys, which does not allow large molecules, including proteins, to pass through. Therefore, in a healthy person, there is no protein in the urine or only a small amount of it (traces) is detected. A protein content of more than 0.1 g/l in a single urine sample or more than 0.15 g/l in a daily urine sample is regarded as proteinuria.

If protein is detected in urine, its composition is qualitatively determined by electrophoresis, which increases the diagnostic value of the analysis.

Why is a 24-hour urine test for protein prescribed?

A short-term increase in protein in the urine may be due to physiological reasons (intake of large amounts of protein foods, heavy physical activity, hypothermia or overheating, stress, sudden change in body position before collecting material).

Pathological causes of proteinuria are diseases of the kidneys, cardiovascular and endocrine systems, including:

• nephritis;
• congestive heart failure;
• hereditary tubulopathies;
• collagenoses.

If these diseases are present or suspected, patients are prescribed a 24-hour urine test for protein.

Other indications for the study are:

• severe infectious diseases;
• feverish conditions;
• poisoning with nephrotoxic poisons (sublimate, salts of heavy metals);
• overdose of nephrotoxic antibiotics (aminoglycosides, streptomycin).

In addition, the indication for testing 24-hour urine for protein is the detection of increased protein concentration in a general urine test.

Since a short-term increase in protein in the urine can be caused by physiological reasons, a differential diagnosis between physiological (short-term) and pathological (permanent) proteinuria is called upon to analyze 24-hour urine for protein. The main goal is to assess the patient's protein loss over a 24-hour period.

Detection of Bence Jones protein is characteristic of multiple myeloma. With increased permeability of the capillary walls of the renal glomeruli, albumin appears in the urine.

How to properly collect daily urine

In order for the research results to be accurate and reliable, you should carefully follow the rules for preparing and collecting daily urine:

• the patient adheres to the usual water and food regimen;
• urine collection is carried out in a previously prepared clean container with a lid with a volume of at least three liters (a special container for collecting daily urine can be purchased at a pharmacy);
• in the morning the patient must toilet the external genitalia and urinate into the toilet, noting the time, which will be the starting point of the time interval;
• During the day, all urine should be collected in a container, which is stored closed in a cool and dark place;
• the first morning urine is not collected for analysis; instead, the first morning urine of the next day is collected;
• when sent to the laboratory, the patient notes the amount of urine collected per day (daily diuresis);
• the collected urine is thoroughly mixed, poured into a small container of 100-150 ml and delivered to the laboratory.

Factors influencing the results of the study

There are a number of factors that can have a significant impact on the results of 24-hour urine protein testing. Falsely elevated results are caused by urine contamination with feces, as well as taking the following medications:

• sulfonamides;
• penicillin;
• cephalosporins;
• X-ray contrast agents containing iodine.

Therefore, thorough toileting of the external genitalia before starting urine collection is so important. In addition, it should be repeated after defecation.

Forced diuresis caused by taking diuretics, including those of plant origin, as well as drinking large amounts of liquid, leads to falsely low results.

With increased permeability of the capillary walls of the renal glomeruli, albumin appears in the urine.

Taking this into account, it is necessary that patients adhere to the usual water regime during the collection of 24-hour urine, and also do not take medications that can affect the results of the study.

Decoding the result: norm and deviations

On average, a healthy person excretes 50–80 mg of protein in the urine (the upper limit of normal is 150 mg). With significant physical activity, protein excretion increases and can reach 250 mg/day. This phenomenon is considered physiological proteinuria, that is, it is not a sign of any disease.

Depending on the amount of protein loss per day, proteinuria is divided into three degrees:

• moderate– less than 1 g;
• average– from 1 to 3 g;
• pronounced– from 3 g and above.

A protein loss of less than 500 mg per day usually indicates the presence of chronic pyelonephritis and a number of other kidney diseases, in which the glomerular apparatus suffers slightly.

Moderate proteinuria can be a symptom of the following diseases:

• kidney amyloidosis;
• acute and chronic glomerulonephritis;
• toxic nephritis;
• diabetic nephropathy;
• severe heart failure.

Severe proteinuria is characteristic of nephrotic syndrome.

The combination of proteinuria with hematuria indicates diffuse or focal damage to the urinary tract, and with leukocyturia - about their infectious damage.

Protein loss in urine may be associated with other reasons, for example, infectious diseases or damage to the central nervous system. During pregnancy, starting from the second half, proteinuria is often caused by the development of OPG-preeclampsia, or late toxicosis of pregnancy.

On average, a healthy person excretes 50–80 mg of protein in the urine. With significant physical activity, protein excretion increases and can reach 250 mg/day.

If protein is detected in urine, its composition is qualitatively determined by electrophoresis, which increases the diagnostic value of the analysis. Thus, the detection of Bence Jones protein is characteristic of myeloma. With increased permeability of the capillary walls of the renal glomeruli, albumin appears in the urine. The appearance of myoglobin indicates muscle damage, and hemoglobin indicates intravascular hemolysis of the blood, which can be caused by various reasons (hemolytic crisis, transfusion of incompatible blood, poisoning with hemolytic poisons).

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There are four main causes of proteinuria:

• glomerular filtration disorders, such as preeclampsia or glomerulonephritis;
• disorders of tubular reabsorption, such as acute tubular necrosis;
• overload, for example with multiple myeloma or rhabdomyolysis;
• Acute physical stressors, such as acute illness or exercise.

Proteinuria measurement

indicator strip

It is necessary to collect a medium portion of urine. The analysis is performed within 1 hour after collection. The amount of protein in the urine is increased with urinary tract infections, which must be excluded in all cases. Determination of protein in urine using an indicator strip - no, traces, 1 +, 2 +, 3 + and 4 +. In general, 1+, 2+, 3+ and 4+ correspond to 30, 100, 300 and 2000 mg/dL.

The advantages of using indicator strips are the ease of analysis and immediate results. Unfortunately, the determination of protein with an indicator strip does not correlate well with the quantitative determination of protein in 24-hour urine and the protein/creatinine ratio in a urine sample. This results from changes in protein levels throughout the day, which in turn depend on changes in drinking habits, urine output, exercise, diet, recumbent position, and inter-study variations in semi-quantitative measurements. When using test strips, no proteinuria or traces of protein were detected in 66% of pregnant women with hypertension and significant daily proteinuria (>300 mg/day). Moreover, with a dipstick value >3+, it is impossible to adequately predict daily proteinuria levels above 5g/day. Therefore, the clinician should use this semiquantitative method solely as a screening test.

Daily urinary protein excretion is the “gold standard” for quantifying protein in urine. Typically, urine collection begins in the morning after the bladder has completely emptied. To determine daily proteinuria, urine output must be measured over a full 24 hours, including the first urine sample the next morning. The advantage of the method is that it is a standard for diagnosing and determining the progression of the disease. The disadvantage of this method is its cumbersomeness and duration.

The clinician often receives results several days later, making it difficult to make immediate treatment decisions. Often, when performing this examination on an outpatient basis, the patient's personal life is at risk, so consent is required. The only way to evaluate the usefulness of a 24-hour proteinuria test is to estimate total urine volume and calculate creatinine excretion.

Urine protein/creatinine ratio

With a relatively constant glomerular filtration rate, creatinine excretion is also constant. It is necessary to correct the results of the protein/creatinine ratio taking into account the normal variation in water excretion during the day. The protein/creatinine ratio in a urine sample has significantly less variability during the day than the test using an indicator strip and is more effective than determining daily proteinuria. Systematic analysis shows that the protein/creatinine ratio correlates well with actual 24-hour proteinuria. The most significant benefit of this study is the exclusion of significant proteinuria, which results in decreased need for 24-hour urine collection, fewer hospitalizations, and possibly fewer medical interventions.

Kidney examination

Microscopy of urine sediment

Detection of specific casts by microscopy of urine sediment often indicates the etiology of the disease.

These include:

• hyaline casts - concentrated urine after physical activity;
• red blood cell casts - glomerulonephritis;
• leukocyte casts - pyelonephritis, interstitial nephritis;
• cylinders of the renal tubules - acute tubular necrosis, interstitial nephritis.

Fractional sodium excretion (FENa%) and urine osmolality (UOsm)

Electrolyte levels and osmolality help in the differential diagnosis of prerenal azotemia and other kidney damage:

• prerenal azotemia - FENa<1 и UOsm >500;
• acute tubular necrosis - FENa >1, UOsm 250-300;
• glomerulonephritis - FENa<1, UOsm - различные значения;
• urinary tract obstruction - FENa - various values, UOsm<400.

Ultrasonography

Kidney ultrasound is the test of choice for newly diagnosed kidney disease. Although ultrasound does not always show any pathology with typical manifestations of eclampsia, it is advisable for atypical manifestations of proteinuria during pregnancy. This is a non-invasive method that does not use ionizing radiation, which allows you to detect dilation of the renal collecting system, determine the size and echogenicity of the kidneys, kidney tumors and manifestations of cystic kidney disease. Transvaginal ultrasound is a very good adjunct to the diagnosis of distal ureteral stones. Most cases of renal colic are diagnosed based on ultrasound and clinical symptoms; other imaging methods are rarely used.

Intravenous pyelography

Currently, intravenous pyelography is used less frequently in the absence of the need for special information when examining the renal collecting system and confirming kidney stones before surgical treatment. If intravenous pyelography in addition to other imaging modalities is necessary during pregnancy, minimize fetal exposure by limiting the number of images (preliminary plain abdominal radiographs only, early and late postcontrast abdominal radiographs).

CT scan

Non-contrast helical computed tomography (CT) is the gold standard for evaluation of renal colic and has a sensitivity of 95% and specificity of 98% for detecting kidney stones. However, during pregnancy the fetus is exposed to significant radiation, and alternative imaging modalities are therefore preferred. In addition to renal ultrasound, targeted CT is used.

Magnetic resonance urography

Recent advances in magnetic resonance imaging (MRI) allow the use of magnetic resonance urography as an adjunct to ultrasound in the evaluation of renal colic/urinary tract obstruction in pregnancy. The method does not involve ionizing radiation, and the risks to the fetus are low.

Percutaneous kidney biopsy

Percutaneous renal biopsy is rarely indicated during pregnancy, but its use is justified in cases of unexplained renal failure and/or proteinuria and hematuria, if graft rejection is suspected. Kidney biopsy is a relatively safe procedure, and the risk of significant bleeding requiring a blood transfusion is approximately 0.1-0.3%.

Diagnosis

Preeclampsia

Preeclampsia is hypertension and proteinuria occurring after 20 weeks of pregnancy. When proteinuria first appears after 20 weeks of pregnancy, this diagnosis should be considered first. According to the International Consensus Group definition, significant proteinuria is a daily proteinuria level of 300 mg/day. With daily proteinuria >5 g/day, severe preeclampsia is diagnosed. However, proteinuria is not detected in all cases of preeclampsia, and it is not necessary for clinical diagnosis. In fact, proteinuria is absent in 14% of cases of eclampsia and 13% of cases of HELLP syndrome (hemolysis, increased liver enzymes and low platelet levels). In the absence of proteinuria, clinical diagnosis is made using hypertension and other clinical characteristics - newly diagnosed liver dysfunction, increased platelet count and platelet count<100 000 с признаками гемолиза, неврологическими расстройствами, болью в эпигастрии и задержкой роста плода.

Because of the inconsistency between random urine protein dipstick testing and other methods, 24-hour proteinuria or protein/creatinine ratio should be determined in all cases of suspected hypertensive disease. However, there is no consensus on the use of protein/creatinine ratio to detect significant proteinuria. According to one of the consensus statements, significant proteinuria is defined as a urine protein/creatinine ratio >30 mg/mmol. While 24-hour proteinuria remains the gold standard for diagnosing significant proteinuria, in pregnancy the urinary protein/creatinine ratio shows a reasonable correlation with 24-hour proteinuria and can be used to provide timely results in the treatment of new and outpatient patients. The advantage of determining the protein/creatinine ratio in urine is the possibility of excluding significant proteinuria and overdiagnosis of preeclampsia. Some authors have not found a specific cut-off point for excluding significant proteinuria, others have suggested a reasonable exclusion ratio of 0.2.

Although there is widespread agreement that the urinary protein/creatinine ratio is a valid alternative, there are still situations in which 24-hour proteinuria testing or serial measurement of the urinary protein/creatinine ratio may be recommended. It is believed that with high levels of proteinuria, the correlation of the protein/creatinine ratio in urine is lost, and daily proteinuria will improve the diagnosis of severe preeclampsia. In addition, serial determination of urinary protein/creatinine ratio or 24-hour proteinuria may confirm the progression of gestational hypertension to mild preeclampsia.

Glomerulonephritis

When admitting patients with edema, hypertension and acute renal failure, it is difficult to differentiate from preeclampsia. Edema is often found in the periorbital area, vulva and extremities. Since treatment of preeclampsia must be carried out according to an urgent special plan, the first task of the clinician is to exclude glomerulonephritis from the differential diagnosis. Urinalysis tests for hematuria, red blood cell casts, white blood cells, and mild to moderate proteinuria. Because of the characteristic etiology of glomerulonephritis, a comprehensive serologic evaluation and possibly a renal biopsy are necessary. The treatment plan depends solely on the specifics of the disease.

Acute tubular necrosis

Acute tubular necrosis usually occurs after hypovolemic or septic shock and is accompanied by sudden severe hypotension. However, tubular damage can be caused by nephrotoxic substances. They come exogenously, as with the administration of aminoglycosides or radiological contrast agents, or endogenously due to rhabdomyolysis. A history of turbid brown urine or the presence of renal tubular casts and FENa >1 in the urine can distinguish acute tubular necrosis from other renal disease.

Treatment is strict fluid balance to avoid overload and supportive care. Although large doses of furosemide are commonly used to improve diuresis, randomized trials have found that such treatment has no effect on the rate of recovery.

Prerenal azotemia

Prerenal azotemia is the most common type of renal failure in the absence of pregnancy. Prerenal azotemia in pregnancy is the result of decreased intravascular volume or changes in vascular resistance; decreased intravascular volume occurs with bleeding, dehydration, GI losses, or trauma. Renal vascular resistance increases when taking various drugs - NSAIDs or when perfusion decreases due to renal artery stenosis. Urinalysis, FENa, and blood urea nitrogen/creatinine ratio (usually >20:1) help differentiate between prerenal azotemia and kidney disease. Treatment is correction of intravascular volume deficiency or removal of the etiological agent.

Obstructive uropathy

The importance of identifying urinary tract obstruction as a cause of proteinuria is that the problem can be easily remedied. Patients usually present with complaints of pain in the lower abdomen or girdle pain. Urine electrolyte testing reveals low FENa, high osmolality, and a high blood urea nitrogen/creatinine ratio. Ultrasound reveals bilateral hydronephrosis or enlarged bladder. The severity of hydronephrosis allows for differential diagnosis with physiological hydronephrosis, observed in most pregnant women. Once the obstruction is removed, post-obstructive diuresis occurs and fluid balance must be monitored to prevent hypovolemia.

Conclusion

New proteinuria during pregnancy should prompt the clinician to look for manifestations of preeclampsia, but the absence of proteinuria does not exclude it. However, not all cases of proteinuria in pregnancy are associated with hypertensive disease, and the clinician should be familiar with other causes and the necessary evaluation.

Urinalysis is the most prescribed test for pregnant women; not a single gynecologist appointment is complete without submitting urine for diagnosis. The main indicator that the attending physician looks at is the protein content in the urine. The detection of even a small amount of protein structures is called proteinuria (albuminuria) in pregnant women and indicates the course of negative processes in the kidneys of the expectant mother.

Proteinuria during pregnancy

The kidneys are a filter that removes substances that the body does not need and retains useful substances necessary for normal functioning. In a healthy person, a protein molecule cannot appear in the urine because its mass is too large to penetrate the glomeruli of the kidneys. If protein structures are detected in extremely small quantities, the doctor may consider this fact to be a variant of the norm, however, if the limits are exceeded, then the condition of the pregnant woman requires treatment.

Changes in the composition of urine during pregnancy

As the baby grows in the womb, the load on the expectant mother’s kidneys increases with each subsequent week of pregnancy: it is necessary to remove more and more waste products, as well as help maintain an optimal balance of substances in the blood of the woman and the child.

At the same time, the conditions for normal kidney function deteriorate significantly: the protective forces of the pregnant woman are reduced, the enlarging uterus puts pressure on the bladder and other organs of the urinary system.

Proteinuria in pregnant women can be suspected if there is a white sediment in the urine

In addition, a pregnant woman always has a high level of hormones that affect the functioning of the kidneys: the vascular walls become more permeable, as does the filtration system of these organs. As a result, substances are found in the urine that normally should not leave our body - proteins.

Types of proteinuria

The appearance of protein structures in urine is not always a pathology. In certain cases, this condition of the expectant mother is called functional proteinuria and is considered as a variant of the norm.

The detection of protein in the urine of a pregnant woman, not exceeding 0.3 g per day, refers to benign (functional) albuminuria, which does not require treatment and is corrected by diet or daily routine.

If the amount of protein exceeds the norm and is constantly growing, this indicates a pathological form of proteinuria. It does not depend on the period of gestation of the child and is provoked by one of the diseases of the kidneys, heart and blood vessels. In this case, the concentration of protein in urine can be from three to ten grams per day.

It is also possible to distinguish two more types of proteinuria, caused by toxicosis in the early (prerenal) and late stages (preeclampsia). If in the first case the protein content in the urine does not exceed 1 g/day, then this condition is temporary and in most cases does not pose a threat to life. With gestosis, even a small amount of protein in the urine (up to 0.5 g/l) indicates nephropathy - kidney damage, which requires control and stabilization of the pregnant woman's condition. In complex cases of nephropathy, accompanied by pathologies, the woman’s health should not be ignored, as this can cause death for both mother and child.

In extrarenal proteinuria, during the period of genital infection, there may be a high number of blood cells, bacteria, epithelial cells and pus, which gives a false positive result for protein in the urine

Toxicosis in the first trimester can also be extremely difficult, in which case the expectant mother needs hospital treatment. In extreme cases, to save a woman’s life, termination of pregnancy is recommended.

Video: urine analysis during pregnancy

Causes and factors for the development of proteinuria

If albuminuria is benign in nature, then the reasons for its appearance may be different, and the fault does not always lie in kidney disease.

Functional proteinuria is divided into subgroups:

• isolated - characterized by the absence of negative symptoms, while the protein content in the urine does not exceed 300 mg per day;
• transient - the appearance of protein in the urine is not permanent and is also not accompanied by other symptoms;
• nutritional - caused by non-compliance with the recommended diet, consumption of protein foods, as well as pickled and spicy foods, alcohol-containing drinks;
• congestive - occurs due to the very fact of pregnancy and pressure of the uterus on the organs of the urinary system, as well as circulatory disorders and impaired urine outflow.

Benign proteinuria is a temporary phenomenon that is not accompanied by unpleasant symptoms and is not dangerous for the pregnant woman and her baby.

To confirm/exclude proteinuria, doctors recommend additional urine tests: Nechiporenko, Kakovsky-Addis, etc.

The causes of benign albuminuria are:

• violation of the correct shape of the spine;
• kidney prolapse;
• power loads;
• non-compliance with drinking regime;
• stress, hypothermia are factors influencing the development of transient proteinuria.

The latter is often diagnosed in case of violation of recommendations for urine collection, insufficient personal hygiene of the pregnant woman, as well as in the case of infection of the urinary tract, for example, urethritis.

Factors in the development of pathological albuminuria

If the appearance of protein in the urine is pathological, the reasons may be:

• kidney inflammation;
• kidney amyloidosis (a disease caused by metabolic disorders);
• kidney cysts;
• urolithiasis disease;
• oncology or benign kidney tumor;
• autoimmune diseases;
• pathologies of the cardiovascular system, heart disease.

An exacerbation of any of these diseases can cause the appearance of protein in the urine, regardless of the trimester of pregnancy.

Protein in urine caused by toxicosis

With toxicosis of the first trimester of pregnancy, proteinuria can be caused by dehydration, which develops due to prolonged vomiting, excessive salivation and metabolic disorders. By the 14th week, the protein content in the urine normalizes due to a decrease in the manifestations of toxicosis.

Prerenal (non-renal) proteinuria during early toxicosis rarely exceeds 1 g/day

If the detection of protein in the urine occurs in the third trimester, then this serves as a signal about the onset of gestosis. This condition can develop in a pregnant woman due to a disruption in the functioning of the central nervous system, a conflict between the organisms of the mother and the fetus, or the accumulation of harmful metabolic products in the uterus or placenta. Pregnant women with a history of the following diseases are prone to the formation of gestosis:

• hypertension;
• kidney pathologies;
• anemia;
• predisposition to allergies;
• smoking;
• foci of progressive microbial infection (tonsillitis, caries).

Functional overload of the kidneys in the second half of pregnancy leads to the development of gestosis

Symptoms of albuminuria in pregnant women

If proteinuria is functional, then usually the expectant mother does not notice any symptoms of the disease. Sometimes slight swelling of the extremities may occur, and the woman suddenly discovers that the ring no longer fits on her finger. Also, when collecting urine for analysis, which late pregnant women take every week, you can see a loss of transparency, the presence of a light suspension or the appearance of foam, which indicates the possible entry of protein into the urine.

Foam in the urine that persists after settling may be a sign of proteinuria

Much more serious are the symptoms of proteinuria caused by the course of an infectious and inflammatory process in the kidneys. In this case, the following signs are noted that require immediate consultation with a doctor:

• high body temperature (from 37.5 to 39.5 O C);
• the appearance of a feeling of chills;
• headache;
• frequent urge to urinate, accompanied by pain and burning;
• pain in the lower abdomen or lumbar region.

As a rule, such symptoms are signs of pyelonephritis or cystitis, but the doctor will make an accurate diagnosis after testing.

Manifestations of early toxicosis, which can also be accompanied by loss of protein, are known to every woman who has a child:

• nausea and vomiting;
• salivation;
• loss of appetite;
• weight loss.

If proteinuria is caused by gestosis in later stages, then the symptoms will be different:

Impaired kidney function and detection of protein in the urine always accompany gestosis, which is why in the third trimester of pregnancy periodic urine testing is so important before each visit to the doctor.

Diagnosis of proteinuria in pregnant women

A general urine test is the main one in recognizing albuminuria in pregnant women. Before taking the test, you must follow the recommendations to help avoid errors in protein determination:

• on the eve of diagnosis, exclude physical activity;
• 3 days before the test, do not be nervous and avoid stressful situations;
• the day before the test, you need to exclude foods with a high protein content (eggs, cottage cheese, fish and meat);
• dress warmly and not get too cold;
• If possible, the pregnant woman should stop taking medications 3 days before the test.

At the same time, we should not forget about the general rules for collecting urine:

• buy a sterile container for biomaterial in advance;
• carry out hygiene procedures before collecting urine;
• collect an average portion of morning urine for examination;
• Store urine taken for analysis for no more than 2 hours.

The doctor compares the results obtained with normal values. A woman is considered healthy if the amount of protein in the urine is not detected or does not exceed 0.033 g per liter, while a figure of up to 0.14 g/l is considered a variant of functional proteinuria.

Table: normal values ​​of protein in urine in pregnant women

If protein is periodically detected in urine tests, then it is worth conducting a 24-hour urine test.

The main excretion of protein usually occurs during the daytime, so it is important to analyze not only morning urine, but also daily urine

The doctor prescribes it to make sure that the occurrence of proteinuria was not accidental. At the same time, the rules for collecting the fluid allocated over 24 hours are different:

• Morning urine should not be collected for diagnosis;
• Before each urination, it is necessary to perform genital hygiene;
• starting from the next urination, during the day, including the morning portion of urine of the second day, it is necessary to collect all produced urine, which is stored in the refrigerator;
• 24 hours of urine is submitted for diagnostics in one large sterile container (at least 2 liters), on which information about the pregnant woman and the date of delivery of the biomaterial are signed.

Depending on the results of the study, the doctor prescribes treatment and makes a verdict on the need for hospitalization of the expectant mother.

Differential diagnosis

When making a final diagnosis, the severity of proteinuria in a pregnant woman is important; to determine it, it is recommended to take several repeated general urine tests and calculate the amount of protein lost per day. The doctor must determine the type of albuminuria, whether it is a pathological, gestational type or is a normal variant for the expectant mother. If the detection of protein in the urine is associated with a causative factor (physical activity, stress, poor diet), then proteinuria is functional and requires correction of the pregnant woman’s regimen and diet.

If the daily protein level in the urine of a pregnant woman is exceeded, an examination in a hospital is necessary to detect the pathology that provokes proteinuria

If other abnormal indicators are detected in the urine, for example, a high number of bacteria, leukocytes, erythrocytes, the woman is referred for consultation to a urologist or nephrologist, who determine the presence of pathologies in the urinary system (cystitis, pyelonephritis, glomerulonephritis, etc.) To confirm the diagnosis, a culture is performed urine for microflora, as well as ultrasound examination of the kidneys with Dopplerography of the uteroplacental blood flow.

To diagnose gestosis, a pregnant woman is prescribed general and biochemical blood and urine tests, and blood clotting tests. It is necessary to monitor the ratio of drunk and excreted fluid to detect hidden edema, as well as monitor the dynamics of weight gain and changes in blood pressure in accordance with the increasing duration of pregnancy.

A complete examination will allow you to make a correct diagnosis for the expectant mother and maintain the health of the woman and her baby.

Treatment of proteinuria in pregnant women

Depending on the symptoms that accompany the appearance of protein in the urine, further treatment tactics are selected that are safest for both mother and child.

Cause of proteinuria - diseases of the urinary system

If the diagnosis shows that the cause of protein getting into the urine is inflammatory or infectious processes in the kidneys or bladder, then first of all the patient is prescribed antibiotic therapy - taking drugs that relieve inflammation, as well as diuretics that flush out microbial waste products and toxins.

Antibiotics of the penicillin group (Amoxiclav, Flemoxin Solutab) are considered the safest for mother and fetus; they are less toxic and effective against pathogens of pyelonephritis, cystitis and other diseases, and can be used for different periods. The use of these drugs is justified if the benefit of treatment for the mother outweighs the risk to the fetus.

In addition, cephalosporins (Ceftriaxone, Cefazolin), Furadonin and macrolides (Macropen, Vilprafen), which are prescribed in the second and third trimesters, do not have a negative effect on the fetus.

An expectant mother can take antibiotics only with the permission of a doctor; self-medication is not allowed due to the great danger of some types of antibiotics that negatively affect the fetus or have a mutagenic effect.

Additional drugs that reduce inflammation can be herbal medications that have a mild diuretic effect: Canephron and Cyston. If necessary, pregnant women can take Paracetamol to lower their temperature.

Paracetamol is the safest of all antipyretics for the expectant mother and child

Traditional medicine is the main assistant in the treatment of expectant mothers, since most medications are prohibited for use. Diuretic herbs and herbal infusions that relieve inflammation, have antimicrobial and diuretic effects, serve as an aid in the treatment of pyelonephritis and kidney diseases:

• lingonberry or strawberry leaves;
• cranberries;
• chamomile;
• thyme;
• raspberries;
• horsetail;
• coltsfoot, etc.

In addition to the usual plants that help with kidney diseases, I recommend paying attention to the herb called Pol-Fal. Not everyone knows about this plant, but it has long been included in the most effective herbal remedies that help fight inflammation of the kidneys and other organs of the urinary system. From my own experience, I can say that taking an infusion of this plant helped me cope with cystitis, which plagued me during pregnancy, even without the use of antibiotics.
The thing is that half-palm has a good diuretic effect, and does not provoke the loss of electrolytes by the body. An infusion of the herb relieves inflammation in the kidneys and bladder, is a good antiseptic, normalizes metabolic processes and lowers blood pressure, which is so important in the last stages of pregnancy. I recommend preparing a half-paly infusion at the rate of 2 tablespoons of raw materials per glass of boiling water. You can brew the plant in a thermos or use a water bath for better effect.
I always drank the infusion before meals, but it is extremely important to use a straw and rinse your mouth with water after drinking. The fact is that saturated infusions destroy tooth enamel, which already suffers from excessive calcium loss during pregnancy. By drinking 50 ml of infusion 2 times a day for 10 days, you can forget about the unpleasant manifestations of cystitis, and urine tests also become good. If you are predisposed to allergies, suffer from severe urolithiasis or osteoporosis, then using half-palu is prohibited.

Among the methods of physiotherapy for kidney inflammation, pregnant women are recommended to use healing mud and warm paraffin to improve blood circulation, and pine baths. Procedures using currents and magnets are prohibited.

A pregnant woman must follow a diet in which it is necessary to avoid the use of seasonings, excessively salty, spicy foods, concentrated broths and meat. You need to drink as much fluid as possible (up to 2 liters), and also eat diuretic fruits and vegetables.

Surgery during pregnancy is performed for emergency reasons when the situation poses a danger to the life of the mother and fetus. For example, if it is necessary to decapsulate the kidney in order to reduce intrarenal pressure or remove abscesses when an abscess develops.

Treatment of gestosis

If gestosis is detected, against the background of which proteinuria occurs, the pregnant woman is indicated for hospitalization in a hospital for a period of 2 weeks and until birth, depending on the severity of the condition, in order to relieve the current symptoms and preserve the life of the mother and child. Home regime is allowed only in the initial stages of the development of gestosis, when the pregnant woman suffers only from swelling. If the expectant mother is diagnosed with nephropathy, preeclampsia or eclampsia (high blood pressure accompanied by seizures), then hospitalization is vital. In the latter case, the best solution is usually early delivery.

Video: treatment of gestosis and getting rid of edema

In the Department of Pregnancy Pathology in perinatal centers, they are fighting gestosis in the second or third trimesters. The main condition for treatment is the absence of stress in the woman, rest, rest and bed rest. For this purpose, you can resort to traditional methods of therapy: drink infusions of motherwort, valerian and other sedative herbs.

The following approved drugs are used to lower blood pressure:

To reduce edema, diuretic preparations are used, including leaves of lingonberry, rosehip, St. John's wort or string. A pregnant woman must strictly observe the drinking regime - drinking more than a liter of water per day is prohibited, and salt restriction is also indicated. The expectant mother's food should be light, rich in protein and vitamins.

To eliminate the symptoms of gestosis in the form of edema, herbal diuretics are often prescribed

If a patient’s ultrasound with Doppler sonography reveals disturbances in blood flow in the placenta or uterus, then doctors recommend taking Actovegin or Curantil. To prevent placental insufficiency, B vitamins, tocopherol, ascorbic acid, and methionine are prescribed.

If it is necessary to improve blood circulation, pregnant women are often prescribed droppers with glucose, saline, and plasma substitutes (Reopoliglucin). Oxygen therapy sessions and the use of oxygen cocktails are also recommended to ensure that the fetus receives sufficient oxygen.

Treatment prognosis and possible complications

The duration and success of therapy depends on the severity of the disease that caused proteinuria. Thus, with timely treatment of inflammatory processes in the kidneys with antibiotics, the prognosis is favorable. Cases of spontaneous abortion caused by intoxication and fever are extremely rare.

In case of gestosis of moderate severity in the absence of effect from treatment for 10 days, negative dynamics of the woman’s condition, as well as the failure of resuscitation efforts in severe form of gestosis within 3 hours, early delivery is recommended. Stable nephropathy and complicated eclampsia, which causes intrauterine growth retardation of the child, despite all the treatment, leads to the same result.

If, in case of late gestosis, the therapy provides a lasting result, confirmed by urine tests, and ultrasound and cardiac monitoring studies do not detect developmental disorders of the child, then the pregnant woman can give birth on her own and on time.

Prevention of proteinuria in pregnant women

To avoid loss of protein by the body of the expectant mother, excreted along with urine, it is necessary to follow these recommendations:

• monitor the condition of the kidneys by regularly taking urine tests;
• monitor the volume of fluid consumed and excreted for timely detection of the early stage of gestosis;
• notify the gynecologist if sediment or foam is detected in the urine;
• follow a diet with limited salt and drinking regime;
• Constantly monitor blood pressure and weight;
• undergo appropriate and timely treatment if bacteria are detected in the urine;
• maintain personal hygiene.

Timely detection of gestosis during pregnancy is an extremely important task for the observing gynecologist, since this disease still remains the first in terms of maternal mortality in Russia. Monitoring the composition of urine by taking tests, following a diet, controlling weight and blood pressure is the key to the health of a pregnant woman and her child. Even a single appearance of protein in the urine is a reason for an early retake of the test and additional examination.