Rationale: It is known that oocytes fail to be recovered from some large follicles observed in human ovaries by conventional ultrasound examination. The prediction of oocyte recovery is particularly important when planning in vitro fertilization in women with low follicle numbers.

Objective: To describe a new ultrasound-based imaging technique, to which we have given the name virtual sonographic folliculoscopy, and to evaluate its ability to predict oocyte recovery from patients with poor response to ovarian stimulation.

Methods: We report a technique for visualization of the cumulus oophorus within the cavity of antral ovarian follicles, based on transformation of 2-dimensional sonographic recordings, taken from the vagina, to 3-dimensional virtual reconstructions. The prediction of the presence of an oocyte-cumulus complex within the follicles is confronted with the actual yield of oocytes by follicle aspiration.

Results: The cumulus-oocyte complexes were clearly visible within some, but not all, large antral follicles. In a group of 20 women with poor response to ovarian stimulation, treated by in vitro fertilization, the presence of a cumulus-oocyte complex in aspirated follicular fluid confirmed the folliculoscopy-based prediction in 17 cases. 

Conclusions: Virtual sonographic folliculoscopy appears to be a useful tool for the prediction of oocyte recovery from antral follicles resulting from ovarian stimulation of poor responder patients.