Endocrine Abstracts

Polycystic ovary syndrome (PCOS) is the commonest cause of anovulatory infertility; anovulation in PCOS is characterised by arrest of antral follicle growth that may reflect the abnormal endocrine environment. However, it has recently been shown that preantral follicle development is also abnormal in PCO (Webber et al, Lancet 2003, 362 1017). In that study, the proportion of follicles in the primordial, resting, phase, was reduced, compared to normal ovaries, in tissue from both ovulatory and anovulatory women with PCO and there was a reciprocal increase in the proportion of primary (early growing) follicles. The purpose of this study was to further define differences between normal and PCO in early folliculogenesis, specifically, (1) to include analysis of an intermediate stage of preantral follicle development - the so-called transitional follicles in which some (but not all) of the single layer of granulosa cells have assumed a cuboidal appearance - and (2) to examine potential differences between anovulatory (anovPCO) and ovulatory women with PCO (ovPCO) in an expanded collection of tissue samples. Follicle stages were defined in cortical biopsies obtained at routine laparoscopy (with informed consent and ethical approval) from 62 women with normal ovaries (1024 follicles analysed), 27 with ovPCO (284 follicles) and 21 with anovPCO (527 follicles). The proportions (% total) of follicles in normal, ovPCO and anovPCO respectively were primordial: 72, 61, 50; transitional: 18, 23, 33; primary 8, 12, 15; secondary 2, 4, 3 (chi-squared = 81.4, p<0.0001). There were significant differences between ovPCO and anovPCO (p=0.0035) and between each PCO group and normal ovaries (ovPCO vs normal, p=0.0035; anovPCO vs normal, p<0.0001). In conclusion, these data confirm the abnormalities of preantral folliculogenesis in PCO and show, for the first time differences in the proportion of transitional follicles between normal and PCO, and significant differences between ovPCO and anovPCO.