Polycystic Ovary Syndrome

Definition: It is a syndrome of ovarian dysfunction & endocrine problems associated with hyperinsulinemia. According to Rotterdam Consensus, the diagnostic criteria of which include the following:
• Evidence of hyperandrogenism, biochemical or clinical(hirsutism acne & male pattern baldness).
• Ovulatory dysfunction; amenorrhoea;oligomenorrhoea.
• Morphological polycystic ovaries.

Women who have at least two of these criteria are said to have polycystic ovary syndrome. Polycystic ovaries diagnosed by ultra-sound should not be confused with PCOS. The ultrasonic picture of polycystic ovary is the presence of 12 or more follicles measuring 2-9 mm in diameter or increased ovarian volume (>10 cm3) on transvaginal ultrasound. A woman having PCO in the absence of an ovulation disorder or hyperandrogenism (asymptomatic PCO) should not be considered as having PCOS, although she may develop symptoms over time, e.g if she gain weight.

Prevalence: PCOS affect around 15-20% of women of reproductive age group.

Aetiology:
The exact aetiology is unknown.
• Genetic factor: the syndrome clusters in families, the prevalence in first degree relatives is 5-6 times higher than in the general population.
• Hormonal factors: Hypersecretion of androgens by theca cells lead not only to the cardinal clinical features of the syndrome, hyperandrogenism, but also lead to inhibition of follicular growth with resultant excess of immature follicles. Hypersecretion of LH stimulate excess production of testosterone by the ovary.
Insulin resistance occur in up to 60 % of women with PCOS especially in those with high BMI. The resultant hyperinsulinaemia stimulate LH- induced androgen production from the ovaries. In the liver elevated insulin causes a decreased production of sex-hormone binding globulin increasing the level of free androgen in the circulation.