A prospective randomized study comparing aspiration only with aspiration and flushing for transvaginal...

To compare aspiration only with aspiration and flushing of ovarian follicles during transvaginal ultrasound (US)-directed oocyte recovery.

Prospective randomized study.

One hundred patients who were undergoing an in vitro fertilization (IVF) treatment cycle.

All patients underwent pituitary desensitization before the administration of gonadotropins. Monitoring of ovarian stimulation and the criteria for the administration of human chorionic gonadotropin were similar in both groups. In patients in whom aspiration alone was used, each follicle was aspirated until it was empty. The US probe was then rotated until every drop of follicular fluid had been aspirated before the next follicle was aspirated and the procedure repeated. For patients who had aspiration and flushing, each follicle was aspirated and then flushed up to a maximum of six times before moving to the next follicle. In both groups, all follicles greater than 10 mm were aspirated.

The indication for IVF and mean age of the patients were comparable in the two groups. There were no significant differences between the aspiration and the aspiration and flushing groups in terms of the number of oocytes retrieved (11 versus 9), the oocyte recovery rates (77.5% versus 77.0%), the fertilization rates (55.6% versus 60.0%), the number of embryos transferred (2 versus 2), or the number of clinical pregnancies (12 versus 13). The time taken for oocyte recovery was significantly shorter (15 versus 30 minutes, P less than 0.00001), and the dose of pethidine required significantly less (50 mg versus 100 mg, P less than 0.00001) in the aspiration only group.

Aspiration alone produces comparable oocyte recovery rates as aspiration and flushing while significantly reducing the length of the procedure and the dose of analgesia required. Aspiration alone suffices for virtually all cases during transvaginal US-directed oocyte recovery.