From the Guidelines
The first-line laboratory tests for diagnosing Polycystic Ovary Syndrome (PCOS) should include total testosterone (TT) and free testosterone (FT) using mass spectrometry, as they are the most accurate measures of biochemical hyperandrogenism 1. When mass spectrometry is unavailable, the free androgen index (FAI) can be employed as an alternative. If TT or FT is not elevated, measuring androstenedione (A4) and dehydroepiandrosterone sulfate (DHEAS) could be considered, noting their poorer specificity. A comprehensive evidence-based PCOS lab panel may also include:
- DHEAS
- Androstenedione
- 17-hydroxyprogesterone
- Fasting glucose
- Fasting insulin
- Hemoglobin A1c
- Lipid profile
- Thyroid function tests (TSH, free T4)
- Prolactin
- A 2-hour oral glucose tolerance test These tests help diagnose PCOS and rule out other conditions with similar presentations. Testosterone and other androgen measurements are crucial as hyperandrogenism is a key diagnostic feature of PCOS. Metabolic testing is important because insulin resistance affects 50-70% of PCOS patients and increases risk for type 2 diabetes. Thyroid function tests and prolactin levels help exclude other endocrine disorders that can mimic PCOS symptoms. For patients with irregular periods, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) may be added to assess for an elevated LH:FSH ratio, though this finding is not specific enough for diagnosis alone. Testing should ideally be performed in the early follicular phase of the menstrual cycle when hormone levels are most stable. Regular monitoring of these parameters is recommended, particularly for patients with metabolic abnormalities, with frequency determined by individual risk factors and treatment response. It is essential to note that the diagnosis of PCOS should not be based solely on laboratory tests, but also on clinical presentation and ultrasound findings, as recommended by recent guidelines 1.
From the Research
Diagnostic Criteria for PCOS
The diagnosis of Polycystic Ovary Syndrome (PCOS) is based on the presence of specific clinical and laboratory features. According to the evidence-based guideline for the assessment and management of PCOS 2, the diagnostic criteria have been refined to include polycystic ovary morphology, which can be assessed with gynecological ultrasound or elevated anti-Müllerian hormone levels.
Laboratory Panel for PCOS
The laboratory panel for PCOS typically includes:
- Hormonal tests to evaluate androgen excess, such as testosterone and androstenedione levels
- Evaluation of ovulatory function, including follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels
- Assessment of metabolic parameters, including glucose and insulin levels
- Lipid profile to evaluate the risk of cardiovascular disease
- Thyroid function tests to rule out thyroid disorders
Key Features of PCOS
The key features of PCOS include:
- Hyperandrogenism, which can be clinical (hirsutism, acne, androgenetic alopecia) or biochemical (elevated androgen levels) 3
- Ovulatory dysfunction, which can manifest as oligomenorrhea or amenorrhea
- Polycystic ovarian morphology, which can be assessed with ultrasound or elevated anti-Müllerian hormone levels 2
Evaluation and Management of PCOS
The evaluation and management of PCOS should include:
- A thorough medical history and physical examination to assess for signs of hyperandrogenism and ovulatory dysfunction
- Laboratory tests to evaluate hormonal and metabolic parameters
- Assessment of risk factors for endometrial cancer, mood disorders, obstructive sleep apnea, diabetes, and cardiovascular disease 4
- Treatment options, such as hormonal contraceptives, metformin, and lifestyle intervention, to manage menstrual abnormalities, hirsutism, and metabolic abnormalities 4