Ultrasonic detection of a cumulus oophorus in patients undergoing in vitro fertilization.

Ultrasonic studies for the detection of a cumulus oophorus were carried out in 57 women taking part in an in vitro fertilization (IVF) program. When intrafollicular echoes were dissociated, clearly prominent from the follicular wall, they were considered to be a sure cumulus mass, and when they were only slightly prominent, they were suspected to be a nondissociated cumulus. All patients had at least one ultrasonically visible cumulus. A cumulus was seen in 50% of the follicles and 70% of them were dissociated. Cumuluses were also seen in follicles less than 18 mm in diameter but a significantly higher number of them were not clearly dissociated. The number of observed dissociated cumuluses correlated significantly with the number of recovered mature oocytes. However, in 18 patients there were more mature oocytes retrieved than cumuluses identified by ultrasound. When a cumulus mass is seen, it can be taken as evidence of a sign of maturity of that particular follicle and oocyte. However, mature oocytes are also found where no cumulus was seen by ultrasound. Lack of visible cumulus has little significance in predicting the maturity of the oocyte.