Laboratory Testing for Gynecologic Wellness Visit with Abnormal Uterine Bleeding
For any patient presenting with abnormal uterine bleeding, order a pregnancy test (β-hCG), complete blood count with platelets, and thyroid-stimulating hormone (TSH) level as essential first-line laboratory tests. 1
Core Laboratory Panel
Mandatory Tests for All Patients
Pregnancy test (β-hCG): Must be performed in all reproductive-age women to rule out pregnancy complications, including life-threatening ectopic pregnancy and trophoblastic disease where delayed diagnosis worsens prognosis 1, 2
Complete blood count (CBC) with platelets: Essential to assess for anemia from blood loss and to evaluate platelet count, particularly important given that coagulopathies are a recognized cause in the PALM-COEIN classification 1, 3, 4
Thyroid-stimulating hormone (TSH): Thyroid dysfunction is a common nonstructural cause of abnormal uterine bleeding and must be evaluated in the initial workup 1, 5
Additional Laboratory Tests Based on Clinical Presentation
Hormonal Evaluation for Ovulatory Dysfunction
When history suggests anovulation or oligoovulation (irregular cycles, prolonged unopposed estrogen exposure):
Prolactin level: Evaluate for hyperprolactinemia as a cause of anovulation 1, 5
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH): Consider when evaluating for premature ovarian failure or polycystic ovary syndrome 1, 2
Testosterone and dehydroepiandrosterone sulfate (DHEAS): Order when hyperandrogenic conditions are suspected 1, 2
Coagulation Studies
- Coagulation profile: Indicated when clinical history suggests bleeding disorder (heavy bleeding since menarche, family history of bleeding disorders, easy bruising, or bleeding with dental procedures), as von Willebrand disease is the most common coagulation defect causing menorrhagia 5
Metabolic Assessment
- Liver function tests: Consider in patients with suspected systemic disease or when history suggests hepatic dysfunction 2
Risk-Stratified Approach to Endometrial Sampling
While not strictly a "laboratory test," endometrial tissue sampling is critical in specific populations:
High-Risk Patients Requiring Endometrial Biopsy
Age ≥35 years with recurrent anovulation: Increased risk for endometrial cancer from prolonged unopposed estrogen 5
Age <35 years with risk factors: Obesity, history of oligoovulation/anovulation, or failure to respond to first-line medical management 2, 5
Postmenopausal bleeding: Endometrial cancer is the primary concern and must be ruled out 1
Clinical Pitfalls to Avoid
Never skip the pregnancy test: Even in patients who report contraceptive use or deny sexual activity, ectopic pregnancy can be fatal if missed 2
Don't overlook coagulopathy in adolescents: Young women with heavy bleeding since menarche may have undiagnosed von Willebrand disease 5
Recognize when CBC alone is insufficient: A normal hemoglobin doesn't rule out significant bleeding if the patient has been supplementing iron or if bleeding is recent 3
Age-appropriate cancer screening: Women ≥35 years or those with risk factors need endometrial assessment before attributing bleeding to benign causes 2, 5