Gynae: PCOS Flashcards
what is polycystic ovarian syndrome?
common endocrine disorder, characterised by excess androgen production and the presence of multiple immature follicles (“cysts”) within the ovaries.
what are the clinical features of PCOS?
- Hyperandrogenism
- acne, hirsutism, obesity
- anovulation
- oligomenorrhoea or amenorrhoea
- infertility
- hair loss in male pattern
what are the Rotterdam criteria
used for making a diagnosis of of PCOS. need 2 for a dx
- oligoovulation or anovulation presenting with irregular or absent menstrual periods
- hyperandrogenism characterised by hirsutism and acne
-
polycystic ovaries on ultrasound
- 12 or more in 1 or both ovaries (string of pearls)
- ovarian volume over >10cm3
what are some problems women may suffer from if they have PCOS?
- insulin resistance and diabetes
- acanthosis nigricans
- cardiovascular disease
- hypercholesterolaemia
- endometrial hyperplasia and cancer
- OSA
- depression and anxiety
- sexual problems
what are some differential diagnosis for PCOS
- simple obesity
- premature ovarian failure
- thyroid disease
- hyperprolactinaemia
- CAH
- androgen secreting tumours
- cushings syndrome
describe the effect of insulin resistance in PCOS
when someone is resistant to insulin the pancreas has to make more insulin to get a response from the cells. insulin promotes the release of androgens from the ovaries and adrenal glands, therefore higher levels of insulin result in higher levels of androgens. insulin also suppresses sex hormone-binding globulin production in the liver. SHBG normally binds to androgens and suppresses their function. reduced SHBG further promotes hyperandrogenism in women with pcos
high insulin contributes to halting development of follicles in the ovaries leading to anovulation and multiple partially developed follicles
what 3 things can help reduce insulin resistance?
diet
weight loss
exercise
what blood tests are required to diagnose PCOS?
- Sex hormone binding globulin (SHBG)
- total testosterone
- free androgen index (FAI) - raised in PCOS
- FSH, LH, TFT, Prolactin - differentials
all tests done in the early follicular phase of the menstrual cycle - day 2-5 - know what FSH and LH levels are at this point
what is free androgen index calculated from? will it be raised, low or normal in PCOS?
sex hormone binding globulin (SHBG) & total testosterone
raised in PCOS
what do the hormone tests for PCOS typically show?
LH, FHS, testosterone, insulin, oestrogen, and FAI
raised LH
raised LH:FSH ratio
raised testosterone
raised insulin
normal or raised oestrogen
raised FAI
what investigations other than bloods are needed when investigation PCOS
pelvic ultrasound scan
transvaginal ultrasound is gold standard for visualising the ovaries - string of pearls as follicles arranged around the periphery of the ovary or ovarian volume of 10cm3 or more
not reliable in adolescents at diagnosing PCOS
how is diabetes screen for in PCOS and what are the results?
2 hour 75g oral glucose tolerance test (OGTT)
(taking baseline fasting plasma glucos, give 75g glucose drink and measure glucose after 2 hours)
impaired fasting glucose = fasting glucose of 6.1-6.9 mmol/l
impaired glucose tolerance = plasma glucose 7.8-11.1 mmol/l at 2 hours
diabetes = plasma glucose 11.1mmol/l at 2 hours
name 4 causes of hirsutism other than PCOS
- Medications such as phenytoin, ciclosporin, corticosteroids, testosterone and anabolic steroids
- Ovarian and adrenal tumours that secrete androgens
- Cushings syndrome
- Congenital adrenal hyperplasia
why is weight loss so important in PCOS?
weight loss alone can result in ovulation and restore fertility and regular menstruation, improve insulin resistance, reduce hirsutism and reduce risk of associated conditions
what medication can be given and how does it help weight loss in PCOS?
Orlistat
lipase inhibitor which stope absorption of fat in the intestine
given to women with BMI over 30
