Polycystic Ovarian Syndrome

Overview – Polycystic Ovarian Syndrome

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder in women of reproductive age, characterised by hyperandrogenism, menstrual irregularity, and polycystic ovaries. It arises from disrupted hypothalamo-pituitary-ovarian signalling and is associated with infertility, metabolic syndrome, and increased long-term risks including endometrial cancer and type 2 diabetes. Timely recognition and multidisciplinary management are key.

Definition

Polycystic ovarian syndrome (PCOS) is a hormonal disorder defined by at least two of the following (Rotterdam criteria):

1. Oligo- or anovulation
2. Clinical and/or biochemical signs of hyperandrogenism
3. Polycystic ovaries on ultrasound

Aetiology

• Genetic: Sex-limited autosomal dominant inheritance
  • ~50% chance of inheritance if female offspring
• Environmental/metabolic factors influence expression (e.g. obesity, insulin resistance)

Pathogenesis

• Disruption of the hypothalamo-pituitary-gonadal axis:
  • ↑ Gonadotropin-releasing hormone (GnRH) pulsatility
  • ↑ Luteinising hormone (LH) and ↓ Follicle-stimulating hormone (FSH)
    → Stimulates thecal cells to produce excess androgens
    → Suppressed granulosa cell function → follicular arrest
• Follicular arrest:
  • Follicles grow to mid-antral stage but fail to mature
  • Granulosa layer thins over time → poor oestrogen conversion
  • Result: Persistent anovulation + hyperandrogenism

Morphology

• Polycystic ovaries on ultrasound:
  • Enlarged ovaries with >12 peripheral immature follicles
  • Described as a “string of pearls” appearance

Clinical Features

Reproductive Features

• Oligomenorrhoea or amenorrhoea
• Anovulation → infertility, recurrent miscarriage
• Enlarged, cystic ovaries

Hyperandrogenism

• Acne
• Hirsutism (excess body/facial hair)
• Deepening of voice
• Elevated serum testosterone

Metabolic Dysfunction

• Insulin resistance
• Obesity
• Dyslipidaemia
• Increased risk of type 2 diabetes mellitus (D2M)
• Increased risk of hypertension and cardiovascular disease

Long-Term Risks

• Unopposed oestrogen exposure → endometrial hyperplasia/cancer
• Fertility challenges
• Metabolic syndrome (Syndrome X)

Diagnosis

• Clinical features: Menstrual irregularity, hirsutism, acne
• Pelvic ultrasound: Bilateral polycystic ovaries
• Blood tests:
  • ↑ Serum testosterone
  • Rule out differentials:
    • Hypothyroidism
    • Cushing’s syndrome
    • Congenital adrenal hyperplasia

Management

Treatment Goals

• Reverse signs of androgen excess
• Restore ovulation and menstrual regularity
• Improve fertility
• Prevent metabolic complications

First-Line Treatments

• Combined oral contraceptive pill (COCP) or IUD
  • Regulates menstruation, reduces hirsutism
• Anti-androgens (e.g. spironolactone)
• Weight loss and lifestyle changes
  • Improves insulin sensitivity
  • Reduces risk of diabetes and cardiovascular disease
• Metformin
  • Improves insulin resistance
  • Promotes ovulation and fertility

Fertility-Focused Treatment

• Ovulation induction: Clomiphene citrate, letrozole, or gonadotropins
• Consider referral to fertility specialist if unsuccessful

Prognosis

Women with PCOS have increased lifelong risks of:

• Endometrial cancer (due to unopposed oestrogen)
• Type 2 diabetes mellitus
• Hypertension and cardiovascular disease
• Persistent subfertility if not adequately managed

Summary – Polycystic Ovarian Syndrome

Polycystic ovarian syndrome (PCOS) is a genetic and hormonal condition marked by hyperandrogenism, irregular menstruation, and metabolic dysfunction. It presents a major cause of infertility and carries increased risks of type 2 diabetes and endometrial cancer. Management targets symptom relief, menstrual regulation, fertility, and metabolic risk reduction. For a broader context, see our Reproductive Health Overview page.