Mechanism of proteinuria in pregnancy

The article was professionally consulted with Specialist Doctor I Le Hong Lien - Doctor of Pregnancy Ultrasound - Department of Obstetrics and Gynecology - Vinmec Central Park International General Hospital.

Pregnant women should have regular urinalysis, especially in the last months of pregnancy, to detect proteinuria. The presence of proteinuria in the urine reflects a number of medical conditions that need to be monitored and treated promptly. What is the cause and mechanism of proteinuria in pregnancy?

For normal pregnant women, there may be a small amount of protein in the urine, when proteinuria exceeds 0.3 g in 24 hours or more than 1g/l is considered positive proteinuria.
When proteinuria appears above the normal level, it is necessary to diagnose the cause for monitoring and treatment as well as prognosis. If the protein is present after 20 weeks of gestation, it could be a sign of preeclampsia. However, if before pregnancy or before 20 weeks of gestation, the presence of proteinuria in the urine is considered a sign of pre-existing kidney disease.
Proteinuria during pregnancy is usually determined through a urinalysis.

2.1. Due to changes in anatomical and physiological structures, proteinuria occurs. However, proteinuria is usually less than 300mg/24h and does not require treatment.
Mechanism: In pregnant women, there is a change in the function of the urinary system, both in terms of anatomical and physiological structure. The size of the kidney is usually larger than normal, leading to dilation of the calyces - pyelonephritis and ureters due to the compression of the fetus into the urinary tract, the renal perfusion is also increased, protein can escape from the glomerular membrane. presence of protein in the urine. At the same time, increased renal hemodynamics changes capillary wall permeability and decreased tubular reabsorption, leading to the appearance of proteinuria.
2.2. Due to preeclampsia. Mechanism: In pre-eclampsia, vascular endothelial cells are damaged, along with the occurrence of an excessive inflammatory response in pregnant women, leading to increased glomerular capillary permeability, edema and bleeding. show proteinuria. In addition, pre-eclampsia reduces the reabsorption capacity of renal tubular cells, resulting in the appearance of protein in the urine, including proteinuria of low molecular weight and high molecular weight. Due to kidney diseases such as nephrotic syndrome, glomerulonephritis, pyelonephritis,... Mechanism: Normally, the glomerular membrane does not allow protein to pass through due to its high molecular weight. When diseases damage the glomerular membrane, protein can pass through the glomerular membrane to release protein into the urine.
In addition, some other factors cause proteinuria during pregnancy such as:
Stress Exposure to high temperatures Fever Dehydration Excessive exercise Leukemia, lupus erythematosus, chronic kidney disease, inflammation joints and diabetes. Diabetes, high blood pressure

If the patient has a history of kidney disease, during pregnancy, it is necessary to have regular tests, monitor edema, urine output, and take medication as prescribed by the doctor. Simultaneous monitoring in nephrology and obstetrics to coordinate treatment of renal disease and symptoms. The benefits of treatment for the mother and the fetus should be properly weighed. The use of drugs in pregnant women needs to be very cautious because some drugs can cross the placental barrier and affect the fetus.
If proteinuria is detected from the 20th week, it is necessary to think of preeclampsia, the patient needs to closely monitor the mother's clinical condition such as hypertension, edema, headache, epigastric pain, right lower quadrant pain. , ... and the development of the fetus regularly so that timely measures can be taken to ensure the safety of the mother's life and that of the child, if possible.
For other causes of proteinuria, the cause should be treated, such as controlling blood sugar if it is due to diabetes. If proteinuria is caused by hypertension, it is necessary to control blood pressure
Regular gentle exercise regularly, eat in moderation and take medications as prescribed, eat less salt in meals, drink plenty of water than.
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The pregnancy process is monitored by a team of highly qualified doctors Regular check-ups and tests, early detection of abnormalities Pregnancy All-inclusive products to facilitate the birthing process Newborns receive comprehensive care