Prospective randomized trial of the effect of two flushing media on oocyte collection and fertilization rates after in vitro fertilization

OBJECTIVE: To assess the value of heparinized saline as a flushing medium for oocyte recovery. DESIGN: Prospective randomized study. SETTING: Academic tertiary referral center for fertility treatment. PATIENT(S): Thirty-five patients, with both ovaries intact having IVF-ET. INTERVENTION(S): Patients were randomized either to have the follicles of the left or right ovary flushed with heparinized normal saline at the time of oocyte recovery for IVF-ET. The contralateral ovary was flushed with heparinized culture medium. Oocytes obtained from each side were cultured separately and assessed for fertilization 18-21 hours after insemination. MAIN OUTCOME MEASURE(S): Collection and fertilization rates. RESULT(S): A total of 481 follicles were aspirated yielding 366 oocytes. Of these, 240 fertilized. From the side flushed with saline 185 oocytes were collected from 237 follicles, which was not significantly different from 181 oocytes collected from 244 follicles on the side flushed with culture medium (odds ratio = 1.23; 95% confidence interval = 0.79-1.92). Similarly, there was no significant difference observed in fertilization rates between oocytes obtained after saline (median 71.4%) and culture medium flush (median 75.0%) (odds ratio = 1.08; 95% confidence interval = 0.68-1.72). CONCLUSION(S): Heparinized normal saline is an equally good but cheaper and more convenient medium than standard heparinized culture medium and could replace it for flushing follicles during oocyte recovery for IVF-ET procedures.