Polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is characterised by oligomenorrhoea, hyperandrogenism, and anovulation. It’s a common disorder, as it affects approx. 10% of women. It’s the most common cause of hyperandrogenism in females.

Symptoms usually begin in adolescence.

Risk factors

• Obesity
• Diabetes mellitus
• Family history

Pathomechanism

The pathomechanism is unknown. One hypothesis is that obesity leads to insulin resistance and hyperinsulinaemia, which increases the frequency of GnRH pulses from the hypothalamus, which stimulates LH more than FSH. This leads to increased androgen production and decreased follicular maturation in the ovaries. However, many PCOS patients are not overweight.

Another hypothesis is that the ovarian capsule is thickened, which prevents follicles from rupturing, causing follicles to accumulate and grow into cyst.

Clinical features

• Oligomenorrhoea or amenorrhoea
• Hyperandrogenism
  • Hirsutism
  • Acne
  • Male-pattern hair loss
• Other symptoms
  • Overweight or obesity
  • Type 2 diabetes
  • Mood disorders

The chronic anovulation is a risk factor for endometrial hyperplasia and cancer.

Diagnosis and evaluation

We should test for biochemical evidence of hyperandrogenism, by measuring serum androgens. We can also measure an LH:FSH ratio of > 3:1.

Transvaginal ultrasound is essential to look for polycystic ovaries.

The diagnosis is made based on the Rotterdam criteria. According to these criteria, at least two of these three criteria must be present:

• Oligo/anovulation
• Hyperandrogenism (clinical or on labs)
• Polycystic ovaries on ultrasound

After diagnosis, we should screen for diabetic, cardiovascular, and hepatic complications.

Differential diagnosis

It’s important to rule out other causes of oligomenorrhoea:

• Physiological oligo-amenorrhoea in teenagers
• Non-classic CAH – by measuring 17-hydroxyprogesterone
• Pregnancy – by measuring hCG
• Thyroid disease – by measuring TSH
• Hyperprolactinaemia – by measuring prolactin

Treatment

All overweight patient should undergo lifestyle changes to achieve weight loss and increase physical activity. These interventions improve both physical and psychiatric symptoms.

Combined oral contraceptive pills decrease the hyperandrogenism, restore normal menstrual cycles, and provide protection against endometrial cancer. If they’re not sufficient, we can add antiandrogens like spironolactone or cyproterone acetate.

Metformin is also commonly used. It restores normal menstrual cycles in 50% of women.

If weight loss is not sufficient to treat infertility in those with infertility who desire pregnancy, we should use drugs to induce ovulation.