From the Guidelines
Diagnosing PCOS requires meeting at least two of three criteria from the Rotterdam consensus: irregular or absent menstrual periods, clinical or biochemical signs of excess androgens, and polycystic ovaries on ultrasound, as stated in the 2023 International PCOS Guidelines 1. The diagnostic process typically begins with a detailed medical history and physical examination, looking for symptoms like irregular periods, excess facial or body hair, acne, and weight gain.
- Blood tests are essential to measure hormone levels, including testosterone, DHEAS, androstenedione, LH, FSH, estradiol, prolactin, and thyroid hormones, as well as to check for insulin resistance through fasting glucose and insulin levels.
- A transvaginal ultrasound is performed to examine the ovaries for multiple small follicles (cysts), with the best criterion being an excessive number (≥20) of 2–9 mm follicles per ovary (follicle number per ovary, FNPO) 1. It's important to rule out other conditions with similar symptoms, such as thyroid disorders, hyperprolactinemia, congenital adrenal hyperplasia, and Cushing's syndrome.
- Early diagnosis is crucial as PCOS increases risks for type 2 diabetes, cardiovascular disease, endometrial cancer, and infertility, allowing for timely intervention and management of these potential complications. The 2023 International PCOS Guidelines recommend using serum AMH as a valuable surrogate for elevated FNPO, especially if FNPO is not available 1. The most accurate diagnostic approach for PCOS is based on a combination of clinical, biochemical, and ultrasound findings, with a focus on individualized assessment and management to improve quality of life and reduce morbidity and mortality risks 1.
From the Research
Diagnostic Criteria for Polycystic Ovary Syndrome (PCOS)
The diagnostic criteria for PCOS involve the presence of at least two of the following three criteria:
- Chronic anovulation
- Hyperandrogenism (clinical or biological)
- Polycystic ovaries 2
Key Diagnostic Features
Key features that aid in the diagnosis of PCOS include:
- Menstrual irregularity
- Hyperandrogenism, which can be clinical (such as hirsutism, acne, and alopecia) or biochemical (elevated levels of androgens)
- Polycystic ovary morphology (PCOM) on ultrasound, characterized by the presence of at least 25 small follicles (2 to 9 mm) in the whole ovary and an ovarian size of more than 10 mL 2, 3
Biochemical Markers
Biochemical markers that can aid in the diagnosis of PCOS include:
- Elevated levels of luteinizing hormone (LH) and a decreased level of follicle-stimulating hormone (FSH)
- Elevated levels of total testosterone, free testosterone, and other androgens such as androstenedione
- Calculated testosterone indices such as free androgen index (FAI), calculated free testosterone (cFT), and calculated bioavailable testosterone (cBT) 3, 4, 5, 6
Clinical Assessment
Clinical assessment is crucial in the diagnosis of PCOS and includes:
- A thorough medical history
- Physical examination to assess for signs of hyperandrogenism such as hirsutism, acne, and alopecia
- Ultrasound to evaluate ovarian morphology
- Laboratory tests to evaluate hormonal levels and rule out other conditions that may mimic PCOS 2
Diagnostic Challenges
Diagnosing PCOS can be challenging, especially in adolescents, due to the variability in clinical presentation and the overlap with normal pubertal changes 2, 4
Establishing Cut-Off Values
Establishing cut-off values for androgen markers is essential for the accurate diagnosis of PCOS. Studies have shown that calculated testosterone indices such as FAI, cFT, and cBT are useful markers for distinguishing PCOS from non-PCOS 3, 6
Hormonal Parameters
Hormonal parameters that are commonly assessed in the diagnosis of PCOS include:
- LH and FSH levels
- Total testosterone and free testosterone levels
- Androstenedione and dehydroepiandrosterone sulfate (DHEAS) levels
- Sex hormone-binding globulin (SHBG) levels 5, 6
Anthropometric Parameters
Anthropometric parameters such as body mass index (BMI) and waist-to-hip ratio are also important in the assessment of PCOS, as obesity is a common finding in women with PCOS 4