Polycystic Ovarian Syndrome Flashcards
What is the definition of PCOS
Polycystic ovary syndrome is a condition that affects how the ovaries work.
what is the Rotterdam criteria for PCOS
i)Clinical hyperandrogenaemia
ii) oligomenorrhoea (less than 6-9 menses per year)
Iii) 12 or more polycystic ovaries on ultrasound. Or ovaries greater than 10ml
What is the criteria used for diagnosis of PCOS
Rotterdam criteria
What is the most common cause of hirsutism
- PCOS
What is PCOS characterised by
1) multiple small cysts within the ovary representing arrested follicular development
2) excess androgen production from the ovaries (and to a lesser extent from the adrenals)
What conditions is PCOS associated with
- Hyperinsulinaemia and insulin resistance - prevalence of T2DM is 10 times higher than in normal women
- hypertension, hyperlipidaemia and increased cardiovascular risk - metabolic syndrome is 2-3 times higher in PCOS
What are the clinical features of PCOS
- Hirsutism
- Age and speed of onset – usually begins around time of menarche and increases slowly and steadily in teens and twenties
- Menstruation – most people will have some disturbance, typically oligo-/amenorrhoea
- Weight – many people are overweight or obese; this worsens the underlying androgen excess and insulin resistance, and inhibits the response to treatment
why do they think insulin resistance is caused in PCOS
- insulin resistance due to hyperinsulinaemia
- decreased SHBG levels
- increased free androgens
What is SHBG
sex hormone binding globulin
- SHBG is a protein made by your liver. It binds tightly to 3 sex hormones found in both men and women. These hormones are estrogen, dihydrotestosterone (DHT), and testosterone.
What investigations do you use in PCOS
- serum total testosterone
- other androngens
- 17a-hydroxprogesterone
- gonadotrophin levels
- oestrogen levels
- ovarian ultrasound
- serum prolactin
What happens to serum total testosterone in PCOS
- often elevated
describe the hormones of PCOS
- Raised LH with normal FSH, Raised Testosterone (with or without reduced SHBG)
What symptom does raised testosterone cause in PCOS
- acne
- infertility hirsutism
what are the differential diagnosis to PCOS
- Exclude thyroid dysfunction, congenital adrenal hyperplasia, hyperprolactinaemia, androgen-secreting tumours.
What happens to gonadotrophin level in PCOS
- LH hyper secretion in PCOS
What happens to oestrogen levels in PCOS
- oestradiol is usually normal in PCOS but oestrone are elevated due to peripheral conversion
What does ovarian ultrasound show in PCOS
- used to identify cysts, thickened capsule and hyperchogenic stroma in PCOS
what happens to serum prolactin in PCOS
- mild hyperprolactinaemia common in PCOS but <1500mU/L
How do you manage hirsutism as a symptom of PCOS
local - hair removal, eflornithiine cream
Systemic
- Oestrogens (COCP) – should be used first unless CI
- Cyproterone lactate 50-100mg daily – produces amenorrhoea so only given for days 1-14 of each cycle
- Spironolactone 200mg daily – antiandrogen activity
- Finasteride 5mg daily - 5α-reductase inhibitor; prevents formation of DHEA in the skin
- Flutamide – less commonly used due to hepatic SEs
How do you manage menstrual distrubance in PCOS
- cyclical oestrogen/progesterone
- metformin 500mg tablets - reduced hyperinsulinaemia, may improve menstrual cycles, ovulation and hirsutism, promote weight loss
How do you manage sub fertility in PCOS
- Clomifene 50-100mg daily – given daily on days 2-6; effective in 75% in achieving ovulation; not used for longer than 6 cycles due to increased risk of ovarian cancer
- Low-dose FSH – used for non-responders to clomifene
- Metformin – on its own may improve ovulation and achieve conception
What investigations do you use in PCOS
- Pelvic ultrasound – multiple cysts on the ovaries
- FSH, LH, Prolactin, TSH and testosterone are useful investigations
- Check for impaired glucose tolerance
