Effect of Catheterized Urine Specimen on Diagnosis and Workup of Microhematuria: A Pilot Study

Objectives: Our objective is to assess whether catheterized urine specimen, compared to mid-stream clean catch (MSCC) technique, would lead to a significant decrease in red blood cell (RBC) count, resulting in the need for fewer AMH work ups in the urogynecologic patient population.

Methods: We prospectively obtained a MSCC and catheterized urine sample from 21 new patients at our Urogynecology clinic between February 2022 and July 2022. AMH was defined as 3 or more RBCs per high power field on collected specimens according to the AUA 2020 guidelines. Matched specimens were compared for urinalysis characteristics, prevalence of AMH, and necessity for cystoscopy or renal imaging. Specimens were also compared based on urogynecologic diagnosis. Given a difference of 23 RBC between “low risk” and “high risk” categories in AUA 2020 AMH guidelines, a sample size of 21 urine specimens per group was calculated using P= 0.05, 90% power, to detect 23 RBC difference between.

Results: A total of 42 urine samples were analyzed by microscopic urinalysis. The mean age of participants was 62 (range 38 to 88) with 57% of patients diagnosed with POP and 52% with urinary incontinence. Of these samples, 5 (24%) of MSCC met criteria for AMH compared to 3 (14%) of catheterized ones (P= 0.414). The need for AMH workup decreased from 3 (14%) to 1 (4%) in the MSCC group vs the catheterized group respectively (P= 0.26). Among 12 participants with POP, 4 (33%) of MSCC samples met criteria for AMH compared to 2 (16%) of catheterized samples (P= 0.343) with catheterized specimens showing an average reduction of 6 RBCs compared to MSCC specimens (P= 0.146).

Conclusions: Our pilot study data shows that MSCC specimens in women with POP are more likely to meet criteria for AMH. Collecting a catheterized specimen may help decrease unnecessary AMH work ups in the urogynecologic population. Additional studies are needed to further explore the utility of catheterized urine specimens for AMH screening in women with POP and other urogynecologic conditions