What is the evaluation and management of hematuria in a pregnant patient with no visible bleeding?

Evaluation and Management of Hematuria in Pregnant Patients

For pregnant patients with hematuria but no visible bleeding, ultrasound of the kidneys and bladder is the recommended first-line imaging, with comprehensive workup deferred until after delivery once benign causes have been excluded. 1, 2

Initial Assessment

• Begin with thorough urinalysis with microscopic examination to confirm hematuria (≥3 red blood cells per high-power field) before initiating further evaluation 1
• Rule out common benign causes specific to pregnancy, including urinary tract infection and gynecologic bleeding 2
• Determine if hematuria is glomerular (dysmorphic RBCs, proteinuria, red cell casts) or non-glomerular (normal-shaped RBCs, minimal/no proteinuria) 1, 2
• The incidence of asymptomatic microhematuria in pregnant women is similar to non-pregnant women (approximately 20%) 2, 3
• The risk of malignancy in pregnant patients with hematuria is low compared to non-pregnant adults 1, 2

Diagnostic Algorithm

Laboratory Evaluation

• Complete urinalysis with microscopic examination to assess RBC morphology and count 1, 2
• Urine culture to rule out infection 2, 4
• Assess for proteinuria - significant proteinuria (>1g/day) suggests glomerular disease 1, 2
• Serum creatinine to evaluate renal function 1, 2

Imaging Recommendations

• Ultrasound of kidneys and bladder is the first-line imaging modality for pregnant patients with hematuria 1, 2
• CT, CTU, and MRI with IV contrast should be avoided during pregnancy due to fetal radiation exposure or uncertain effects of gadolinium 1, 2
• MRI without IV contrast may be considered in select cases when ultrasound is insufficient 1, 2

Specialist Referral

• Consider nephrology referral if there is evidence of glomerular disease (proteinuria >1g/day, red cell casts, dysmorphic RBCs) 1, 2
• Consider urology referral for cystoscopy and imaging in adults with microscopically confirmed hematuria in the absence of a demonstrable benign cause 1
• Defer comprehensive urologic workup until after delivery unless findings on ultrasound suggest urgent intervention is needed 1, 2

Follow-up Recommendations

• For patients with negative initial evaluation, repeat urinalysis after delivery 2, 3
• Microscopic hematuria may persist postpartum in approximately 50% of women, warranting follow-up to detect possible underlying mild glomerulonephritis 3
• If hematuria persists postpartum, a full workup should be completed 1, 2

Important Caveats

• Dipstick hematuria is very common during pregnancy (20% of pregnant women) but rarely signifies a disorder likely to impact pregnancy outcome 3
• Rare causes of hematuria in pregnancy include right renal vein hypertension due to compression from the gravid uterus (nutcracker phenomenon) 5
• Do not attribute hematuria solely to pregnancy without appropriate evaluation 2, 6
• Postpartum follow-up is recommended to detect women who have persistent hematuria and presumed underlying mild glomerulonephritis 3