PCOS Flashcards
Pathophysiology of PCOS
Anterior pituitary makes too much LH (2x that of FSH)
Excessive LH causes too much androstindione to be made by theca cells - it enters blood and is converted to estrone by aromatase in adipose tissue
LH levels are so high so surge does not occur to trigger dominant follicle to be released so the follicle stays and becomes a cyst
Ovulation doesn’t occur
Link between insulin and PCOS
Those who are insulin resistant produce more insulin
Insulin can bind to insulin receptors on theca cells causing overproduction of theca cells and overproduction of LH receptors
This increases GnRH production thus leading to more LH production and release
Symptoms of PCOS explained by hormone changes
High levels of androstindione = hirsutism and acne
Lack of LH surge = lack of ovulation and oligomenorrhoea
Insulin resistance causes obesity and acanthosis nigricans
Investigations for PCOS
Bloods: LH:FSH 3:1 in first 5 days of cycle
Oestrogen and testosterone levels raised
USS: classic picture of a necklace of small follicles around periphery of ovary, ovary usually enlarged
Criteria used for diagnosis of PCOS
Rotterdam:
2 of the cirteria must be present
- Oligo/amenorrhoea
- Hyperandrogenism features or hyperandrogenaemia
- PCOS seen on USS
Management of PCOS
Encourage healthy lifestyle - offer weight loss advice as may help with symptoms
COCP for hyperandrogenism and irregular periods
Those wanting to conceive to have OGTT before conception
Prognosis with PCOS
Risk of menodmetrial hyperplasia and cancer if amenorrhoea is persistent and there are high levels of circulating oestrogen
