What is Polycystic Ovary Syndrome (PCOS)?

Polycystic Ovary Syndrome (PCOS): Definition and Overview

Polycystic Ovary Syndrome (PCOS) is a common endocrine and metabolic disorder affecting 8-13% of reproductive-age women, characterized by hyperandrogenic chronic anovulation with significant impacts on fertility, metabolic health, and quality of life. 1, 2

Diagnostic Criteria

PCOS diagnosis is based on the Rotterdam criteria, requiring at least two of the following three features:

1. Oligo- or anovulation (irregular or absent menstrual cycles)
2. Clinical and/or biochemical hyperandrogenism (elevated testosterone, hirsutism, acne)
3. Polycystic ovarian morphology (PCOM) on ultrasound

Other potential causes of these symptoms must be excluded before confirming PCOS diagnosis 2.

Ultrasound Criteria for PCOM

• Transvaginal ultrasound (preferred method): ≥20 follicles per ovary or ovarian volume ≥10 ml 2
• Not recommended for diagnosis in adolescents within 8 years of menarche due to high incidence of multi-follicular ovaries 2

Pathophysiology

PCOS involves multiple interconnected pathological mechanisms:

• Hormonal dysregulation:

  • Acceleration of pulsatile GnRH secretion
  • Hypersecretion of luteinizing hormone (LH)
  • Hypofunction of follicle stimulating hormone (FSH)
  • Ovarian theca stromal cell hyperactivity 1

• Metabolic abnormalities:

  • Insulin resistance and hyperinsulinemia
  • Downstream metabolic dysregulation 1

These abnormalities result in:

• Hyperandrogenism
• Hirsutism
• Follicular arrest
• Ovarian acyclicity 1

Clinical Presentation

Common manifestations include:

• Reproductive symptoms:

  • Irregular menstrual cycles (oligomenorrhea or amenorrhea)
  • Infertility due to chronic anovulation
  • Multiple small antral follicles 3

• Hyperandrogenic symptoms:

  • Hirsutism (excessive body hair)
  • Acne
  • Androgenic alopecia (male-pattern hair loss)
  • Rarely, clitoromegaly 1, 2

• Metabolic features:

  • Obesity (especially abdominal)
  • Insulin resistance
  • Acanthosis nigricans (dark, velvety skin patches) 1

Associated Health Risks

PCOS significantly increases the risk of:

• Metabolic disorders:

  • Type 2 diabetes mellitus
  • Dyslipidemia (elevated LDL, decreased HDL, elevated triglycerides)
  • Metabolic syndrome 1, 4

• Cardiovascular disease:

  • Hypertension
  • Increased cardiovascular risk factors 1, 4

• Reproductive issues:

  • Infertility
  • Endometrial hyperplasia and cancer risk 1

• Psychological disorders:

  • Depression
  • Anxiety
  • Reduced quality of life 3, 5

Diagnostic Evaluation

Key components of PCOS evaluation include:

Clinical Assessment

• Detailed menstrual history
• Assessment of hyperandrogenic symptoms
• Family history of cardiovascular disease and diabetes
• Evaluation for signs of insulin resistance 2

Laboratory Testing

• Hormonal assessment:

  • Total or bioavailable testosterone
  • DHEAS (dehydroepiandrosterone sulfate)
  • 17-hydroxyprogesterone
  • LH/FSH ratio (often >2 in PCOS) 1, 2

• Metabolic screening:

  • 2-hour oral glucose tolerance test
  • Fasting lipid profile
  • Fasting glucose/insulin ratio 1, 2

• Exclusion of other disorders:

  • Thyroid-stimulating hormone (thyroid disease)
  • Prolactin (hyperprolactinemia)
  • Tests for Cushing's syndrome if clinically suspected 1, 2

Important Distinctions

• PCOS should not be confused with isolated polycystic ovaries (polycystic morphology without symptoms or hormonal abnormalities), which occur in 17-22% of the general female population 1

• PCOS prevalence is significantly higher (10-25%) in women with temporal lobe epilepsy, even without antiepileptic drug use 1

Special Considerations in Adolescents

• Diagnosis in adolescents should focus on:

  • Irregular menstruation (>2 years post-menarche)
  • Clinical and/or biochemical hyperandrogenism
  • Ultrasound is not required for diagnosis in this age group 2, 5

• Early identification and management in adolescents is crucial to prevent long-term complications 5, 6

PCOS is a lifelong condition requiring ongoing monitoring and management to address both immediate symptoms and long-term health risks. Early diagnosis and appropriate intervention are essential for improving quality of life and reducing associated morbidity and mortality.