Laboratory Tests for Evaluating Dysmenorrhea
For patients with dysmenorrhea, initial laboratory evaluation should include pregnancy test, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, and thyroid-stimulating hormone (TSH) levels to rule out underlying causes.
Initial Evaluation
- A pregnancy test is essential as the first step in evaluating any menstrual abnormality or pelvic pain 1
- Serum levels of LH, FSH, prolactin, and TSH should be measured to exclude endocrine causes of dysmenorrhea 1, 2
- These tests should be performed between days 3-6 of the menstrual cycle for accurate interpretation 2
Additional Testing Based on Clinical Suspicion
For Suspected Polycystic Ovary Syndrome (PCOS)
- Total testosterone or bioavailable/free testosterone levels to assess ovarian hyperandrogenism 2
- Two-hour oral glucose tolerance test with 75g glucose load to screen for diabetes and insulin resistance 2
- Fasting lipid profile including total cholesterol, LDL, HDL, and triglycerides 2
- Calculate body mass index (BMI) and waist-hip ratio to assess obesity patterns 2
For Suspected Endometriosis
- Transvaginal ultrasound should be performed if secondary dysmenorrhea is suspected 3
- This is particularly important when hormonal treatments and NSAIDs have failed to provide relief 4
For Suspected Bleeding Disorders
- Consider coagulation studies in patients with heavy menstrual bleeding accompanying dysmenorrhea 5
- A bleeding score assessment can help identify women who require additional hematological investigations 5
Special Considerations
- For adolescents, a speculum or bimanual examination is not necessary before prescribing most forms of contraception for dysmenorrhea management 2
- In cases of severe dysmenorrhea, pelvic examination is indicated to identify potential anatomic abnormalities 2
- Progesterone levels measured during mid-luteal phase can help identify anovulation, which may contribute to menstrual pain 2
Follow-up Testing
- If no improvement occurs after 3-6 months of empiric treatment for primary dysmenorrhea, further investigation for secondary causes is warranted 4
- Persistent symptoms despite treatment may require referral to a gynecologist for more specialized testing 4
Common Pitfalls to Avoid
- Don't overlook thyroid dysfunction, which can present with menstrual irregularities and pain 2
- Avoid assuming all dysmenorrhea is primary without appropriate laboratory evaluation, especially with severe symptoms 3
- Remember that laboratory values must be interpreted in the context of the patient's menstrual cycle phase 2
- Don't forget to consider medical conditions that can mimic or exacerbate dysmenorrhea, such as inflammatory bowel disease, interstitial cystitis, or pelvic congestion syndrome 2