Urine bilirubin 1 in pregnant women

Urine bilirubin is a metabolic substance after the destruction of blood cells. Total bilirubin can be divided into unconjugated total bilirubin that is not resolved by the liver and conjugated bilirubin produced by conjugation with glucuronic acid in the liver. Unconjugated bilirubin is insoluble in water and combines with proteins in the blood and cannot pass through the renal tubular filter paper.

Conjugated bilirubin has a small relative molecular mass and high solubility. It can be excreted in the urine through the renal tubular filter paper and is called urinary bilirubin. Because the conjugated bilirubin content in normal people's blood is very low and the filtration rate is very small, total bilirubin cannot be detected in the urine. If the conjugated bilirubin in the blood increases, it can pass through the renal tubular membrane to increase the amount of conjugated bilirubin in the urine, and the urine bilirubin test will be positive.

Judgment experiment

Used for urine testing in patients with liver disease, the total bilirubin in normal people's urine should be negative. For example, in hepatic jaundice and obstructive jaundice, total bilirubin may appear in the urine, while in hemolytic jaundice, the total bilirubin test is generally negative. This item, together with urobilinogen and urobilin, can be used as the basis for the diagnosis of jaundice.

Positive actual meaning:

Liver damage

Inability to absorb indirect bilirubin, also unable to absorb direct bilirubin, resulting in an increase in both direct and indirect bilirubin in the blood, while direct bilirubin is excreted through the kidneys. Therefore, urobilinogen is positive and urine bilirubin is positive.

Bile duct obstruction

Direct bilirubin produced by the liver flows back into the blood, causing positive urine bilirubin.

Positive identification

Hepatic jaundice

When the liver is damaged, its uptake, fusion and clearance of total bilirubin may be impaired. Because the liver's ability to absorb unconjugated bilirubin in the blood is reduced, its concentration in the blood increases. The resulting conjugated bilirubin may, due to liver swelling and pressure on the common bile duct, diffuse through the sinuses between the swollen and necrotic liver and enter the blood circulation, causing an increase in conjugated bilirubin in the blood. It can dissolve in water and be excreted through the kidneys, making the urine bilirubin test positive. In addition, fecal bilirubin absorbed by the gastrointestinal tract cannot be converted into total bilirubin due to liver damage, and is excreted in the urine as urobilinogen. Therefore, both urine bilirubin and urobilinogen are significantly positive in jaundice. In subacute viral infections.