From the Guidelines
To assess Polycystic Ovary Syndrome (PCOS), I recommend ordering a comprehensive panel of laboratory tests including total and free testosterone, sex hormone-binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEAS), androstenedione, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, thyroid-stimulating hormone (TSH), and a lipid panel, as supported by the most recent evidence from 1.
Laboratory Tests for PCOS
The following laboratory tests are essential for assessing PCOS:
- Total and free testosterone
- Sex hormone-binding globulin (SHBG)
- Dehydroepiandrosterone sulfate (DHEAS)
- Androstenedione
- Luteinizing hormone (LH)
- Follicle-stimulating hormone (FSH)
- Prolactin
- Thyroid-stimulating hormone (TSH)
- Lipid panel
Metabolic Tests
Additionally, the following metabolic tests should be performed:
- 2-hour oral glucose tolerance test with insulin levels
- Hemoglobin A1C
Special Considerations
- 17-hydroxyprogesterone should be measured to rule out congenital adrenal hyperplasia, particularly in patients with severe hirsutism or virilization.
- These tests should be performed during the early follicular phase (days 3-5) of the menstrual cycle when possible for accurate hormone assessment.
- Patients should be fasting for the metabolic tests.
Diagnosis of PCOS
The diagnosis of PCOS is based on the Rotterdam criteria, requiring at least two of three features: oligo/anovulation, clinical or biochemical hyperandrogenism, and polycystic ovaries on ultrasound, as discussed in 1 and 1. The laboratory tests help confirm hyperandrogenism, rule out other endocrine disorders that can mimic PCOS, and assess for metabolic complications that frequently accompany PCOS, including insulin resistance, dyslipidemia, and impaired glucose tolerance.
Recent Guidelines
Recent guidelines from 1 recommend evaluating for polycystic ovary syndrome in female adolescents with type 2 diabetes, including laboratory studies when indicated, and using metformin in addition to lifestyle modification to improve menstrual cyclicity and hyperandrogenism in female individuals with type 2 diabetes.
Ultrasound Criteria
The ultrasonographic criteria for diagnosing PCOS, as confirmed by 1, include the presence of multiple follicles in the ovaries, with a threshold of 25 follicles or an ovarian volume greater than 10 mL. However, the use of ultrasound in diagnosing PCOS is no longer recommended within 8 years post-menarche, as stated in 1.
Androgen Measurement
The most accurate androgen measurement for assessing biochemical hyperandrogenism in PCOS diagnosis is total testosterone (TT) and calculated free testosterone (cFT), as informed by the 2023 International PCOS Guideline recommendations in 1. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) is the preferred method for androgen measurement due to its high accuracy.
From the Research
Laboratory Tests for Assessing PCOS
To assess Polycystic Ovary Syndrome (PCOS), the following laboratory tests are ordered:
- 2 hour 75 g oral glucose tolerance test to screen for impaired glucose tolerance and diabetes mellitus 2
- Fasting lipid profile to screen for dyslipidemia 2
- Hemoglobin A1C and/or fasting glucose, although the 2 hour oral glucose tolerance test is preferred by the American College of Obstetricians and Gynecologists and the Endocrine Society as a superior indicator of impaired glucose tolerance/diabetes mellitus 2
Frequency of Laboratory Tests
The frequency of these laboratory tests is as follows:
- 2 hour oral glucose tolerance test: upon diagnosis and every 2-5 years 2
- Fasting lipid profile: upon diagnosis and every 2 years 2
Importance of Laboratory Tests
Laboratory tests are essential in assessing PCOS, as women with PCOS have substantially higher rates of insulin resistance, impaired glucose tolerance, type 2 diabetes, dyslipidemia, and metabolic syndrome compared to women without the disease 2, 3