Providing a urine sample during menstruation often raises concerns about test accuracy. Menstrual blood can introduce factors that influence the reliability of various laboratory analyses.
Impact on Urine Test Results
Menstrual blood can significantly affect the accuracy of urine test results due to potential contamination. When menstrual fluid enters the urine sample, it can introduce red blood cells, white blood cells, and protein, which are typically assessed in a urinalysis. These elements can lead to false positive findings, mimicking conditions like urinary tract infections (UTIs) or kidney disease.
For instance, in tests for urinary tract infections, menstrual blood can cause false positive results for leukocyte esterase, an enzyme produced by white blood cells. Menstrual fluid also contains white blood cells. Similarly, kidney function tests, which often check for protein and red blood cells in urine, can show misleading elevated levels due to menstrual contamination. While urine pregnancy tests primarily detect human chorionic gonadotropin (hCG) and are generally not affected by menstrual blood, other common urine tests can be compromised. Contamination can obscure true results or suggest issues that do not exist, making accurate diagnosis challenging.
Steps for an Accurate Sample
To obtain the most accurate urine sample while menstruating, a “clean catch” technique is recommended to minimize contamination. Begin by thoroughly washing your hands with soap and water to prevent the transfer of germs. Before collecting the sample, carefully clean the genital area using provided antiseptic wipes, wiping from front to back.
It is advisable to insert a fresh tampon or menstrual cup before collection, if possible, to help prevent menstrual blood from entering the urine stream. When ready to collect:
Spread the labia apart with one hand and begin urinating a small amount into the toilet first.
Without stopping the flow, place the sterile collection cup into the urine stream and collect a midstream sample, filling the cup halfway.
Ensure the cup’s inside or rim does not touch the body or any other surfaces during collection.
Finish urinating into the toilet.
Communicating with Your Healthcare Provider
Inform your healthcare provider or laboratory staff if you are menstruating when providing a urine sample. This allows them to interpret the test results accurately, considering potential contamination. Even if a meticulous clean catch technique is followed, traces of menstrual blood can still inadvertently enter the sample. Your provider can use this information to avoid unnecessary further testing or misdiagnosis.
In some cases, especially for highly sensitive tests or if significant contamination is visible, your healthcare provider may recommend rescheduling the test for a later date. They can advise on the best course of action, which might include repeating the test after your period has ended to ensure clearer results. This context helps your medical team make informed decisions about your care and ensures the most reliable interpretation of your health status.