Investigation of Microhematuria in Women

Initial Diagnostic Confirmation

• The American College of Physicians recommends confirming microhematuria by repeating microscopic urine analysis on 2 out of 3 properly collected samples to document ≥3 erythrocytes/HPF before any further investigation, and excluding transient benign causes such as menstruation, vigorous exercise, recent sexual activity, urinary tract infection, or trauma 1, 2

Risk Stratification

• For women with a low risk profile, such as non-smokers with <25 erythrocytes/HPF, the risk of urothelial malignancy is significantly lower than in men, and the American Urological Association recommends a more conservative approach 1, 3

Recommendations Based on Age

• For women aged ≥60 years, a complete urological investigation is recommended, including CT urography and cystoscopy, due to the increased risk of urothelial malignancy with age 1, 3, 4

Minimal Initial Evaluation

• The European Association of Urology recommends a complete urine analysis with sediment examination to identify erythrocyte dysmorphism, erythrocyte casts, and significant proteinuria, as well as serum creatinine and eGFR to assess renal function 2, 3

Indications for Complete Urological Investigation

• The American Urological Association recommends a complete urological investigation, including CT urography and cystoscopy, in women with a history of exposure to chemicals or dyes, macroscopic hematuria, persistent irritative bladder symptoms, previous pelvic irradiation, or analgesic abuse 1, 2, 3

Referral to Nephrology

• The National Kidney Foundation recommends referral to a nephrologist if there is significant proteinuria (protein-to-creatinine ratio >0.2 g/g), erythrocyte dysmorphism >80%, or erythrocyte casts, as these findings suggest glomerular disease 1, 2, 3

Follow-Up

• The American College of Physicians recommends annual urine analysis for 3 years after an initial negative investigation, as well as monitoring of blood pressure and re-evaluation if hypertension, proteinuria, or signs of glomerular bleeding develop 2, 3

Pitfalls to Avoid

• The European Association of Urology recommends not ignoring anticoagulation as a potential explanation for microhematuria, and not relying solely on dipstick testing due to its limited specificity 1, 3