Purpose of the study. This test is done to determine the ability of the kidneys to filter urine. It must be carried out for all pregnant women with preeclampsia, with urinary tract infections, with kidney diseases, and with diabetes mellitus.
Rules for collecting urine. Before the test, intense physical activity, strong tea and coffee are excluded. Urine is collected during the day in one container, which is stored in the refrigerator during the entire collection time. After completing the collection of urine, measure the contents of the container, be sure to mix and immediately pour 70-100 ml into a special container or jar and deliver it to the laboratory, reporting the total volume of urine collected per day.
At the time of delivery of urine to the laboratory, blood is taken for creatinine from a vein.
Investigated parameters. The method is based on the assessment of glomerular filtration by the rate of purification of blood plasma from creatinine, a special product of protein breakdown. This indicator can be determined if you know the concentration of creatinine in the blood, in the urine and the daily volume of urine. This indicator is calculated using a special formula and is called creatinine clearance. Normally, the value of this indicator ranges from 75 to 134 ml / min / 1.7 m2. A decrease in the level of renal filtration indicates kidney damage and occurs with severe complications of pregnancy - gestosis, kidney diseases (pyelonephritis, glomerulonephritis), diabetes mellitus, arterial hypertension, urolithiasis.