Laboratory Workup for Uterine Fibroids
Essential Initial Laboratory Tests
Obtain a complete blood count (CBC) to assess for anemia from heavy menstrual bleeding, and perform a pregnancy test to rule out pregnancy as a cause of uterine enlargement. 1
Core Laboratory Panel
Complete Blood Count (CBC) is the single most important laboratory test, as fibroids commonly cause menorrhagia leading to iron-deficiency anemia that can range from mild to life-threatening (hemoglobin levels as low as 1.1 g/dl have been documented). 1, 2
Pregnancy test (serum or urine β-hCG) must be obtained to exclude pregnancy as the cause of uterine enlargement or bleeding, particularly since pregnancy and fibroids can coexist. 1
Urinalysis should be performed when patients present with pelvic pressure symptoms, urinary frequency, or back pain to exclude urinary tract infection or kidney stones that may mimic or coexist with fibroid-related symptoms. 1
Additional Laboratory Considerations Based on Clinical Presentation
Iron studies and ferritin levels are warranted when the CBC reveals anemia, to confirm iron deficiency and guide replacement therapy, though this is based on standard anemia workup principles rather than fibroid-specific guidelines. 3, 2
Thyroid function tests may be considered as part of the differential diagnosis for menorrhagia, since thyroid disorders can cause similar bleeding patterns, though this is not fibroid-specific. 4
Common Clinical Pitfalls
Failing to recognize severe anemia is a critical error—patients may present with hemoglobin levels below 2.0 g/dl due to chronic blood loss, requiring urgent intervention including blood transfusion and definitive treatment. 2
Overlooking pregnancy testing in reproductive-age women can lead to misdiagnosis, as pregnancy must always be excluded before proceeding with imaging or treatment planning. 1
Not investigating urinary symptoms thoroughly with urinalysis may miss concurrent urinary tract pathology that requires separate management from the fibroids themselves. 1
Laboratory Tests That Are NOT Routinely Indicated
Tumor markers (such as CA-125) are not part of the standard fibroid workup unless malignancy is suspected based on imaging characteristics or rapid growth in perimenopausal women. 1
Coagulation studies are not routinely needed unless the patient has a personal or family history suggesting an underlying bleeding disorder contributing to menorrhagia. 4