Polycystic ovary syndrome

What it is

PCOS is a syndrome of androgen excess with ovarian dysfunction, due to raised androgen and insulin resistance. The Rotterdam criteria put it as US shows polycystic ovaries (12 follicles or more, volume 10ml or more) with oligomenorrhoea and hyperandrogenism (acne, hirsutism, acanthosis nigricans). Two of the following three criteria make the diagnosis:

1. Hyperandrogenism, clinical, that is hirsutism of male pattern, or biochemical, that is a high free testosterone.
2. Oligomenorrhoea or anovulation, checked by a day 21 progesterone.
3. Polycystic ovaries on US: 12 or more follicles measuring 2-9 mm in diameter in one ovary or both, or an ovary with a volume greater than 10 mL.

The same idea in three lines: androgen excess, clinical or biochemical; ovarian dysfunction, oligo-anovulation and/or polycystic ovarian morphology; and exclusion of other androgen excess or ovulatory disorders, which includes, but is not limited to, 21-hydroxylase deficient nonclassic adrenal hyperplasia, thyroid dysfunction, hyperprolactinemia, neoplastic androgen secretion, or drug-induced androgen excess. It affects about 5% of women, or between 5-20% of women of reproductive age, and accounts for over 80% of anovulatory infertility. It is put as disordered luteinising hormone production with peripheral insulin resistance, so LH and insulin are both raised; this increases androgen production, which disrupts folliculogenesis and leads to excess small ovarian follicles, irregular or absent ovulation and hirsutism, and there appears to be some overlap with the metabolic syndrome. A third statement of the criteria requires two of three: infrequent or no ovulation; clinical or biochemical signs of hyperandrogenism or elevated total or free testosterone; and polycystic ovaries on ultrasonography or increased ovarian volume, with irregular periods defined as more than 35 days apart. A high BMI is not part of the diagnostic criteria, though indirect evidence of insulin resistance such as acanthosis nigricans may help the physician suspect the condition.

One drug carries it as a side effect: valproate, used for GTC, myoclonic and absence seizures and for bipolar disorder, lists PCOS among its key side effects beside hepatotoxicity, teratogen with NTD, weight gain, tremor and thrombocytopenia. So in a woman on valproate the syndrome may come from the drug.