Endocrine Abstracts

Polycystic ovary syndrome (PCOS) is the commonest cause of anovulatory infertility, and menstrual disturbances. The mechanism of anovulation is complex but the characteristic ovarian feature is arrest of antral follicles at 5–8 mm in diameter. Follicle arrest probably reflects the abnormal endocrine environment in which elevated LH and or hyperinsulinaemia (together with a relative deficiency of FSH) are important elements. However, recent studies also point to abnormalities of the very earliest (gondotrophin independent) stages of follicle development. In terms of clinical management of infertility, anti-oestrogens such as clomiphene remain the treatment of first choice. Treatment of clomiphene-resistant subjects is difficult; conventional doses of gonadotrophins are associated with high rates of ovarian hyperstimulation syndrome and multiple pregnancy. On the other hand, low-dose gonadotrophin therapy has proven effective in inducing unifollicular ovulation. Weight reduction in obese subjects with PCOS not only increases the chance of fertility but also improves the long-term prognosis with regard to development of diabetes. Insulin sensitising drugs (particularly metformin) may also have a part to play in management of anovulatory women with PCOS but positioning of such therapies still awaits the results of large scale randomised controlled trials.