Few instead of many: human follicle collection from follicular aspirates at oocyte retrieval

BACKGROUND: The aim of this study was to determine if follicular aspirates obtained during oocyte retrieval for IVF were a good source of ovarian follicles for research purposes. METHODS: Follicular aspirates from 86 patients were collected and examined for the presence of follicles, and histological examination of tissue sample found was undertaken. RESULTS: Follicles were only obtained from aspirates of seven out of a total of 86 patients. From these samples a total of 14 follicles was found. The follicles were primordial, primary or secondary, 40-80 microm in diameter. Three of these recovered follicles were cultured and all degenerated within 2 days. In all aspirates some groups of granulosa cells that did not contain follicles or oocytes were found, as was vaginal epithelium that was also identified and verified by histology. CONCLUSIONS: Follicular aspirates are not a useful source of human follicles. Some structures found in the aspirates may be erroneously identified as follicles.