PCOS (polycystic ovary syndrome) – medical revision notes

Key Points

• PCOS is a common endocrine disorder affecting reproductive-aged women
• It is characterised by a combination of hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology
• Early recognition and management are crucial to prevent long-term complications such as type 2 diabetes and cardiovascular disease
• Treatment is multidisciplinary, aiming to manage symptoms and reduce long-term risks

1. Definition

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that affects women of reproductive age. It is diagnosed based on the Rotterdam criteria, which require at least two of the following:

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

It is a syndrome, meaning not all women present with the same set of symptoms, making diagnosis and management individualised.

PCOS is one of the most common endocrine conditions in women of reproductive age and yet the disorder has remained an enigma for many decades, with little progress made towards the improvement of symptoms and wellbeing of patients.

2. Epidemiology

• PCOS is the most common endocrine disorder among women of reproductive age, affecting around 8-13% of women globally
• PCOS is common, with a prevalence of PCOS varies from 5 to 20%. Around 50% of women are not aware that they have PCOS, though many cases may go undiagnosed, or have a delayed diagnosis
• It is also a leading cause of infertility due to anovulation, accounting for around 70% of ovulatory disorders.

3. Risk factors

• Family history of PCOS or diabetes
• Obesity: Excess weight can exacerbate symptoms.
• Insulin resistance
• Sedentary lifestyle: Lack of physical activity is associated with worsening metabolic outcomes.
• Ethnicity: Women of South Asian origin may present with more severe symptoms and higher metabolic risks.

4. Cause

The exact cause of PCOS is not fully understood, but several factors are thought to contribute:

1. Genetic predisposition: There is often a family history of PCOS or type 2 diabetes.
2. Insulin resistance: Hyperinsulinemia increases androgen production by the ovaries.
3. Hormonal imbalance: Elevated levels of luteinising hormone (LH) and androgens contribute to the disruption of ovulation.
4. Environmental factors: Poor diet, obesity, and a sedentary lifestyle can worsen symptoms.

5. Symptoms

PCOS presents with a broad range of symptoms, which can vary in severity:

• Menstrual irregularities: Oligomenorrhoea or amenorrhoea due to ovulatory dysfunction.
• Infertility: Difficulty in conceiving due to anovulation.
• Hyperandrogenism: Hirsutism, acne, and male-pattern alopecia due to elevated androgen levels.
• Weight gain: Many women with PCOS struggle with obesity or difficulty losing weight.
• Acanthosis nigricans: Darkened, thickened skin, typically on the neck or under the arms, indicating insulin resistance.

Acanthosis nigricans on the neck

And in the armpits

Note. PCOS signs and symptoms are typically more severe in people with obesity.

6. Diagnosis

The diagnosis of PCOS is clinical, based on the Rotterdam criteria. Exclusion of other causes of hyperandrogenism and menstrual irregularities is necessary.

Investigations

1. Biochemical tests
   • Total and free testosterone: To assess for hyperandrogenism
   • LH and FSH: The LH ratio may be elevated but is not required for diagnosis
   • Sex hormone-binding globulin (SHBG): Often decreased in PCOS
   • Serum prolactin and thyroid function tests: To rule out other causes of menstrual irregularity
   • Fasting glucose and insulin levels: To evaluate insulin resistance.
2. Ultrasound
   • Pelvic ultrasound: May reveal polycystic ovaries (>12 small follicles or increased ovarian volume >10 ml).
3. Additional assessments
   • Oral glucose tolerance test: Screening for glucose intolerance or type 2 diabetes
   • Lipid profile: To assess for dyslipidaemia.

Differential diagnosis

Several conditions mimic PCOS and should be excluded:

• Hypothyroidism: Can cause menstrual irregularities and weight gain
• Hyperprolactinemia: Can cause oligomenorrhoea and galactorrhoea
• Congenital adrenal hyperplasia (CAH): Causes androgen excess and menstrual disturbances
• Cushing’s syndrome: Excess cortisol can lead to hyperandrogenism and obesity
• Androgen-secreting tumours: Rare but should be considered in cases of severe hyperandrogenism.

7. Treatment

Treatment is tailored to the patient’s symptoms and reproductive goals:

1. Lifestyle modification:
   • Weight loss: Even a 5-10% reduction in body weight can restore ovulation and improve insulin sensitivity
   • Exercise: Regular physical activity improves metabolic parameters and reduces cardiovascular risk.
2. Pharmacological treatment:
   • Combined oral contraceptive pills (COCPs): First-line therapy for menstrual irregularities and hyperandrogenism
   • Anti-androgens: Spironolactone or cyproterone acetate can be added for severe hirsutism or acne
   • Metformin: Used to improve insulin sensitivity, particularly in women with impaired glucose tolerance
   • Clomifene citrate or letrozole: For ovulation induction in women who wish to conceive.
3. Fertility treatments
   • Gonadotropins or in vitro fertilization (IVF) may be needed for women who do not respond to oral ovulation induction agents.
4. Cosmetic treatments
   • Laser hair removal and topical treatments for hirsutism and acne.

8. Complications

PCOS can lead to several long-term complications if not managed appropriately:

• Type 2 diabetes: Women with PCOS have a significantly increased risk due to insulin resistance
• Cardiovascular disease: Dyslipidemia and obesity contribute to increased cardiovascular risk
• Endometrial hyperplasia and cancer: Unopposed oestrogen in women with anovulation increases the risk of endometrial hyperplasia and, eventually, carcinoma
• Infertility: Anovulation makes conception challenging, and treatment may be required
• Psychosocial impact: PCOS can cause anxiety, depression, and decreased quality of life due to body image concerns and infertility.

9. Prognosis

• With appropriate treatment, most women with PCOS can manage their symptoms and lead healthy lives.
• However, the risk of long-term complications such as diabetes, cardiovascular disease, and endometrial cancer persists, necessitating regular monitoring
• Women with PCOS should be encouraged to maintain a healthy lifestyle to minimise these risks.

10. Prevention

• There is no definitive way to prevent PCOS, but modifiable risk factors such as weight management and physical activity can help reduce its severity
• Early diagnosis and intervention can also prevent complications like diabetes and cardiovascular disease.

Regular follow-up is essential, especially in women with risk factors for metabolic syndrome or those with fertility concerns. Educating patients on lifestyle modifications remains a cornerstone of long-term management.