Polycystic ovary syndrome (aka hyperandrogen Chronic Anovulation) is a very common cause of amenorrhoea and oligomenorrhoea. It is important as it is associated with excessive andorgen secretion and insulin resistance.
Typical patients
  • Hyperandrogenism
    • Hirsutism – male pattern hair growth / excessive female hair growth
    • Acne
  • Polycystic ovaries
  • Oligo-ovulation
  • Insulin resistance – weight gain
  • Can also be caused by Cushings, and adrenal hyperplasia


  • Very common!
  • 5-20% of women aged 18-45


  • Essentially unknown
  • Possibly insulin resistance
    • There is certainly a relationship between the two – hard to determine cause and effect
    • Insulin resistance is also associated with obesity – and excess adipose tissue will result in the creation of excess oestrogen! A vicious cycles!



  • Due to anovulation (irregular / absent ovulation)
  • The anovulation can also result in reduced fertility

Weight gain / insulin resistance

  • May be visible by dark patches of skin, particularly on the neck and in skin folds

Masculinisation – due to excessive testosterone production

  • E.g. Hirsutism – excessive hair growth on females. Common during puberty as the hormonal axis matures, and usually transient. If persistent, or presents later in life, suspect another cause (e.g. PCOS)
  • Excessive body hair
  • Acne

Infertility may occur
Symptoms usually begin around the time of puberty, and worsen at the patient gets older.

  • PCOS is unlikely if regular periods have been established before amenorrhoea.


Occurs when the ovaries are stimulated to produces excessive amounts of androgens, usually from excessive release of LH, although hyperinsulinaemia also has a similar effect and plays a role in many cases. The ultimate cause of either of these factors is not clear
  • The cysts seen on USS are actually immature follicles and not true cysts
  • Cysts are about 2-6mm in size


  • ↑ LH
  • ↔FSH
  • ↓ E2 (estradiol)
  • ↑ Testosterone
  • ↑ Prolactin
  • ↑ oestrogen – which ultimately results in increased risk of endometrial hyperplasia / endometrial cancer
  • TFTs – for hyperthyroidism:
    • ↓TSH
    • ↑T4


  • Shows >5 follicles per ovary
  • Sometimes said to look like a string of pearls


  • May show excessive cervical mucus – consistent with excess oestrogen

Risks / complications

  • Insulin resistance and possibly later, Type II diabetes
  • Cardiovascular disease
  • Hypertension
  • Dyslipiaemia – disorders of lipid metabolism
  • Weight gain
  • Miscarriage
  • Autoimmune thyroid disease
  • Acanothosis nigricans – patches of dark skin, typically under the arms and on the back of the neck
  • Increased risk of endometrial cancer due to unopposed oestrogens.


Avoid smoking
Treat diabetes

  • Advise increased exercise
  • Often Metformin is helpful. Can not only improve diabetic symptoms, but can also help menstrual problems (amenorrhoea / oligomenorrhoea), and can help ovulation
  • Metformin recommended by NICE in those trying to conceive

Treat hypertension
Treat hyperlipidaemia
Oral contraceptives – should be progesterone containing, usually POP (so not as to add more oestrogen !) Help to reduce endometrial cancer risk, and reduces circulating androgens. Usually with 3-monthly withdrawal bleeds.
Treatment of hirsutism – if a problem, consider cosmetic treatments (hair removal) or an anti-androgen e.g. cyproterone.

  • Spironolactone and finasteride – are also antiandrogenic, but is teratogenic, so avoid pregnancy!
If trying to conceive, consider:
  • Clomifene – usually used in conjunction with metformin, will help ovulation.
    • Increases the riks of multiple pregnancy and ovarian cancer
    • Monitor effect with USS in at least the first cycle
  • Ovarian drilling – is recommended as second line if clomiphene is not working. Helps to reduce steroid production.
  • COC may help provide regular bleeding, and will reduces the risk of endometrial cancer

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