From the Guidelines
The initial laboratory workup for irregular menses should include a comprehensive evaluation of hormonal and metabolic factors, including pregnancy test (hCG), thyroid-stimulating hormone (TSH), prolactin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol, as well as tests for polycystic ovary syndrome (PCOS) such as total testosterone, free testosterone, dehydroepiandrosterone sulfate (DHEAS), and 17-hydroxyprogesterone 1.
Key Components of the Workup
- Pregnancy test (hCG) to rule out pregnancy as a cause of irregular menses
- Thyroid-stimulating hormone (TSH) to evaluate for thyroid dysfunction
- Prolactin to assess for hyperprolactinemia
- Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to evaluate for ovulatory dysfunction
- Estradiol to assess for adequate estrogen levels
- Additional testing for PCOS, including total testosterone, free testosterone, dehydroepiandrosterone sulfate (DHEAS), and 17-hydroxyprogesterone, as PCOS is a common cause of irregular menses 1
Considerations for PCOS
- PCOS is associated with an increased risk of metabolic syndrome, diabetes, dyslipidemia, and hypertension 1
- Women with PCOS should be screened for cardiovascular disease risk factors, including weight changes, blood pressure, fasting lipid panel, and glycemic control 1
- Metformin is recommended for patients with PCOS who have cardiometabolic features such as abdominal obesity and insulin resistance 1
Additional Testing
- Complete blood count and comprehensive metabolic panel to evaluate for other underlying causes of irregular menses
- Progesterone challenge test for patients with amenorrhea to determine if adequate estrogen is present
- Androgen levels should be measured if hirsutism or virilization is present
- Hemoglobin A1c or fasting glucose should be checked if metabolic issues are suspected A comprehensive approach to the laboratory workup for irregular menses is essential to identify the underlying cause and guide appropriate treatment, which may include hormonal contraceptives, metformin for PCOS, thyroid medication, or other targeted therapies depending on the underlying cause 1.
From the Research
Initial Evaluation
When evaluating irregular menses, a stepwise approach is recommended, including:
- Obtaining a thorough medical history
- Performing a physical examination
- Understanding the characteristics of the menstrual cycle to determine the etiology 2
Laboratory Tests
Selected laboratory tests can help differentiate between various causes of menstrual irregularity, including:
- Anovulation due to an immature hypothalamic-pituitary-ovarian axis
- Endocrine abnormalities
- Anatomic abnormalities 3
- A careful history and physical examination can guide the choice of laboratory tests
Differential Diagnosis
The differential diagnosis of irregular menstrual cycles should consider common conditions and their defining characteristics, such as: