Significance of the ultrasonic morphology of preovulatory ovarian follicles prior to in vitro fertilization.

Forty-eight oocytes were collected from 47 follicles in 36 cycles from 24 patients with tubal infertility by ultrasonically guided percutaneous puncture under local anesthesia. The ultrasonic represented morphology of the aspirated follicles was compared to the presence of an egg-cumulus-mass in the follicular aspirate and the result of oocyte fertilization. There was a higher frequency of a cumulus-mass in the aspirate from follicles containing echoes (90 per cent) compared to ultrasonically empty follicles (37 per cent). Thirty-four oocytes were fertilized corresponding to a fertilization rate of 71 per cent. The mean diameter of follicles in the fertilized group was bigger (20.9 mm) than the mean diameter of follicles in the non-fertilized group (18.5 mm). The fertilization rate was higher in oocytes collected from follicles with internal echoes (87 per cent) compared to echo-free follicles (50 per cent). It seems that the ultrasonic demonstration of a fine cloud projecting into the follicle or a clouding of the cavity increases the possibility of collecting an oocyte suitable for in vitro fertilization.