The urine test during pregnancy is indicated to diagnose any problem that may be affecting the patient’s urinary and renal system. It is a painless and easy-to-collect procedure that can provide information about serious diseases, such as kidney problems1.

Types of Urine Tests

There are three types of tests that can be performed through urine, not only during pregnancy but in general, namely the type 1, urine culture, and 24-hour urine. No specific preparation such as fasting is required beforehand.

The most conventional test, and most requested by doctors, is the type 1 or EAS Urine as it is called in laboratories, which is able to analyze the following elements.

  • Glucose
  • Proteins
  • Ketones
  • Bilirubin
  • Leukocytes
  • Urine pH

In addition to density and nitrite, the presence of blood residues, mucus or any other foreign substance found in the urine will indicate the patient’s problem. If nitrite, leukocytes, or blood are found, the test will indicate a possible urinary tract infection.

This should be confirmed through the urine culture test, which is the only test capable of proving the existence of an infection. Collection is ideally done with the first urine of the day, but it can also be performed with urine collected at any time, depending on the laboratory.

40 to 50 ml are needed and must be stored directly in a proper plastic container, discarding the first stream as it may contain impurities from the urinary tract.

It is recommended to collect the sample after genital hygiene and at the laboratory, so that the material can be delivered immediately. If collected at home, the urine should be delivered within up to two hours, otherwise it should be discarded for analysis purposes.

The urine test during pregnancy will be performed in two stages, one through a chemical reaction and the second through the analysis of drops of urine under the microscope. Using a microscope it is possible to detect substances that will indicate if something is wrong.

In addition to being used to diagnose infections and being part of routine prenatal tests, urine can also be used to detect and confirm a possible pregnancy2. Conventional tests like type 1 do not confirm pregnancy—a specific test that checks for the amount of HCG hormone in the urine should be performed.

For the urine test to detect and provide a correct result, it is recommended to perform it with a minimum menstrual delay of at least seven days. Each passing day the amount of HCG increases, which makes it possible for the urine test to detect the substance. But in the case of a negative result and delayed period, it is advised to repeat the test within a week or confirm through a beta HCG blood test.

Reference Values for Type 1 Urine Test

As mentioned above, if substances such as leukocytes, nitrites or even blood residues are found in the urine, it signals an apparent infectious condition, which should be investigated with complementary tests. The references serve to indicate normality, and when higher values are found, it means there is an actual reactive infection.

  • Density between 1.005 and 1.030
  • pH from 5.5 to 7.5
  • No presence of protein, ketones, bilirubin, leukocytes, glucose, nitrite, or blood.

Density

Density is compared to the reference values of water, which when pure is equal to 1000. So if the result is 1.008, the urine is well diluted and considered healthy. If it is close to the maximum 1.030, the urine is very concentrated and may indicate dehydration.

pH

pH measures the acidity of the urine, since the kidneys are responsible for eliminating acids from the body. The normal reference for pH is 5.5 to 7.0. If a value lower than normal is found, it may indicate a problem with the renal tubules.

If a value higher than the reference is found, it may indicate the presence of bacteria that is alkalinizing the urine or even the consumption of acidic foods or certain medications. Further investigation with complementary tests and medical analysis is necessary.

Glucose

Glucose is normally filtered by the kidneys and returned to the bloodstream, so when it is found in the urine, it may be a sign of problems in the renal tubules or may occur in diabetics who often lose glucose in the urine3. The presence of the substance indicates excess glucose in the blood or poor kidney function.

If any substance is found in the urine, the doctor will request further tests for confirmation of the diagnosis. Treatment will be indicated for the specific problem, and self-medicating is not recommended.

See also: Urinary Tract Infection During Pregnancy – What Now?

Photo: ken fager, Bethany Brown