Polycystic ovarian syndrome

Useful indicator of general health and underlying disease. Menorrhagia may cause microcytic anaemia, and exacerbate hair loss.

Hypokalaemia may raise the possibility of cortisol excess.

Useful indicator of general health and underlying disease.

Fatty liver is common in both obesity and diabetes. It's also needed as a baseline before starting medical treatments.

Useful indicator of general health and underlying disease.

Unrecognised hypothyroidism is associated with weight gain and menstrual disturbance.

Hyperprolactinaemia of any cause is associated with oligomenorrhoea. 

Mild degrees of hyperprolactinaemia are also seen in PCOS and may not indicate pituitary or other pathology.

Essential for cardiovascular risk stratification.

This should be performed early morning, early follicular phase and off the contraceptive pill. 

Sex hormone binding globulin is typically low in PCOS and Cushing’s. Testosterone is typically but not always mildly elevated in PCOS. High levels (>3.5nmol/l in the author's institution) should prompt a search for other causes, for example virilising tumours or Cushing’s syndrome.

Elevated luteinising hormone: follicle stimulating hormone ratio is often seen in PCOS but is not diagnostic and so is not necessarily performed in all cases.

LH and FSH may both be low in pituitary and hypothalamic causes of oligomenorrhoea, for example associated with low body mass or anorexia or excessive exercise. FSH will be elevated in the secondary amenorrhoea of premature ovarian failure.

This test needs to be performed early morning, early follicular phase and off the contraceptive pill. 

17OHP is a useful initial screen for congenital adrenal hyperplasia - if elevated above 10nmol/l, the patient will require full evaluation: a short synacthen test.

This should be taken on day 21 of the menstrual cycle to indicate ovulation in patients with regular menses and diagnostic uncertainty.

This should also be recorded in patients seeking fertility.

In virilised patients, those with elevated testosterone, or suspected Cushing’s syndrome, or other adrenal pathology, full adrenal androgens should be assessed. These are typically minimally elevated in PCOS, higher in Cushing’s and adrenal tumours. 

Urinary cortsiols form a sensitive but not specific initial screen if Cushing's syndrome is suspected.

If there is a clinical suspicion of Cushing’s syndrome, a low dose dexamethasone suppression test (LDDST) should be performed to seek suppressibility of cortisol.

If androgens are elevated, LDDST should also be performed. Suppressibility of adrenal androgens by more than 40% has been reported as making virilising tumours highly unlikely.

If the baseline 17 hydroxyprogesterone is elevated >10nmol/l, proceed to a synacthen test to confirm or exclude late onset congenital adrenal hyperplasia.

If adrenal androgens are elevated, and do not suppress after dexamethasone testing, a virilising tumour should be suspected and CT or MRI imaging should be peformed.

If androgens are elevated and do not suppress after dexamethasone, imaging of the ovaries and adrenals should be arranged. If no obvious lesion is revealed on imaging, selective venous sampling of the abdomen and pelvis may identify the source of androgens.

This may be useful in cases of diagnostic difficulty where there is evidence of hyperandrogenism but not of ovarian dysfunction.

Typical polycystic appearance is supportive but not diagnostic of PCOS, as it may also be observed in many other conditions for example acromegaly, Cushing's syndrome and many normal women.

Ovarian imaging (by ultrasound or MRI) is also mandatory where there is a suspicion of virilising tumour.

When a virilising tumour is strongly suspected but not visualised on ultrasound scan, MRI pelvis may be helpful and can be combined with adrenal imaging to avoid the abdominal radiation exposure necessary for an adrenal protocol CT scan in a young woman.